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source: palm/trunk/SOURCE/wind_turbine_model_mod.f90 @ 3139

Last change on this file since 3139 was 3139, checked in by Giersch, 6 years ago
Bugfix in calculation of alpha_attack and Bugfix for restarts in combination with grid stretching
Property svn:keywords set to `Id`
File size: 120.6 KB

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1	!> @file wind_turbine_model_mod.f90
2	!------------------------------------------------------------------------------!
3	! This file is part of the PALM model system.
4	!
5	! PALM is free software: you can redistribute it and/or modify it under the
6	! terms of the GNU General Public License as published by the Free Software
7	! Foundation, either version 3 of the License, or (at your option) any later
8	! version.
9	!
10	! PALM is distributed in the hope that it will be useful, but WITHOUT ANY
11	! WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
12	! A PARTICULAR PURPOSE. See the GNU General Public License for more details.
13	!
14	! You should have received a copy of the GNU General Public License along with
15	! PALM. If not, see <http://www.gnu.org/licenses/>.
16	!
17	! Copyright 2009-2018 Carl von Ossietzky Universitaet Oldenburg
18	! Copyright 1997-2018 Leibniz Universitaet Hannover
19	!------------------------------------------------------------------------------!
20	!
21	! Current revisions:
22	! -----------------
23	!
24	!
25	! Former revisions:
26	! -----------------
27	! $Id: wind_turbine_model_mod.f90 3139 2018-07-17 11:30:10Z Giersch $
28	! Bugfix in calculation of alpha_attack
29	!
30	! 3069 2018-06-15 07:56:09Z witha
31	! Initialization of some arrays added
32	!
33	! 3066 2018-06-12 08:55:55Z Giersch
34	! Error message revised
35	!
36	! 3065 2018-06-12 07:03:02Z Giersch
37	! dz was replaced by dz(1), error message concerning grid stretching has been
38	! introduced
39	!
40	! 3049 2018-05-29 13:52:36Z Giersch
41	! Error messages revised
42	!
43	! 2932 2018-03-26 09:39:22Z Giersch
44	! renamed wind_turbine_par to wind_turbine_parameters
45	!
46	! 2894 2018-03-15 09:17:58Z Giersch
47	! variable named found has been introduced for checking if restart data was
48	! found, reading of restart strings has been moved completely to
49	! read_restart_data_mod, wind_turbine_prerun flag has been removed, redundant
50	! skipping function has been removed, wtm_read/write_restart_data have been
51	! renamed to wtm_r/wrd_global, wtm_rrd_global is called in
52	! read_restart_data_mod now, marker * end wtm * was removed, strings and
53	! their respective lengths are written out and read now in case of restart
54	! runs to get rid of prescribed character lengths, CASE DEFAULT was added if
55	! restart data is read
56	!
57	! 2885 2018-03-14 11:02:46Z Giersch
58	! Bugfix in interpolation of lift and drag coefficients on fine grid of radius
59	! segments and angles of attack, speed-up of the initialization of the wind
60	! turbine model
61	!
62	! 2792 2018-02-07 06:45:29Z Giersch
63	! omega_rot_l has to be calculated after determining the indices for the hub in
64	! case of restart runs
65	!
66	! 2776 2018-01-31 10:44:42Z Giersch
67	! wind_turbine_prerun flag is used to define if module
68	! related parameters were outputted as restart data
69	!
70	! 2718 2018-01-02 08:49:38Z maronga
71	! Corrected "Former revisions" section
72	!
73	! 2696 2017-12-14 17:12:51Z kanani
74	! Change in file header (GPL part)
75	!
76	! 2669 2017-12-06 16:03:27Z raasch
77	! filename of turbine output changed to WTM_OUTPUT_DATA. File extension now
78	! includes the nest domain number. Turbine extension changed to "_T##"
79	!
80	! 2576 2017-10-24 13:49:46Z Giersch
81	! Definition of a new function called wtm_skip_global to skip module
82	! parameters during reading restart data
83	!
84	! 2563 2017-10-19 15:36:10Z Giersch
85	! Restart runs with wind turbine model are possible now. For this purpose, two
86	! new subroutines wtm_write_restart_data and wtm_read_restart_data had to be
87	! defined
88	!
89	! 2553 2017-10-18 08:03:45Z Giersch
90	! Bugfix of vertical loop in wtm_tendencies to account for different turbine
91	! heights, bugfix of the interpolation of the u-component concerning the
92	! vertical index and further small adjustments of the programming style
93	!
94	! 2410 2017-09-06 08:16:30Z Giersch
95	! Revise error message PA0462
96	!
97	! 2349 2017-08-10 15:44:04Z Giersch
98	! Add parameter pitch_rate to namelist and revise/add error messages
99	!
100	! 2343 2017-08-08 11:28:43Z Giersch
101	! Unit correction in Doxygen comments
102	!
103	! 2323 2017-07-26 12:57:38Z Giersch
104	! Change unit number of file WTM_DATA from 201 to 90
105	!
106	! 2322 2017-07-26 08:30:28Z Giersch
107	! Bugfix of error message and assign error numbers
108	!
109	! 2257 2017-06-07 14:07:05Z witha
110	! Bugfix: turb_cl_tab and turb_cd_tab were set to zero before being allocated
111	!
112	! 2233 2017-05-30 18:08:54Z suehring
113	!
114	! 2232 2017-05-30 17:47:52Z suehring
115	! Adjustments to new topography concept
116	!
117	! 2152 2017-02-17 13:27:24Z lvollmer
118	! Bugfix in subroutine wtm_read_blade_tables
119	! Addition of a tip loss model
120	!
121	! 2015 2016-09-28 08:45:18Z lvollmer
122	! Bugfix of pitch control
123	!
124	! 2000 2016-08-20 18:09:15Z knoop
125	! Forced header and separation lines into 80 columns
126	!
127	! 1929 2016-06-09 16:25:25Z suehring
128	! Bugfix: added preprocessor directives for parallel and serial mode
129	!
130	! 1914 2016-05-26 14:44:07Z witha
131	! Initial revision
132	!
133	!
134	! Description:
135	! ------------
136	!> This module calculates the effect of wind turbines on the flow fields. The
137	!> initial version contains only the advanced actuator disk with rotation method
138	!> (ADM-R).
139	!> The wind turbines include the tower effect, can be yawed and tilted.
140	!> The wind turbine model includes controllers for rotational speed, pitch and
141	!> yaw.
142	!> Currently some specifications of the NREL 5 MW reference turbine
143	!> are hardcoded whereas most input data comes from separate files (currently
144	!> external, planned to be included as namelist which will be read in
145	!> automatically).
146	!>
147	!> @todo Replace dz(1) appropriatly to account for grid stretching
148	!> @todo Revise code according to PALM Coding Standard
149	!> @todo Implement ADM and ALM turbine models
150	!> @todo Generate header information
151	!> @todo Implement further parameter checks and error messages
152	!> @todo Revise and add code documentation
153	!> @todo Output turbine parameters as timeseries
154	!> @todo Include additional output variables
155	!> @todo Revise smearing the forces for turbines in yaw
156	!> @todo Revise nacelle and tower parameterization
157	!> @todo Allow different turbine types in one simulation
158	!
159	!------------------------------------------------------------------------------!
160	MODULE wind_turbine_model_mod
161
162	USE arrays_3d, &
163	ONLY: tend, u, v, w, zu, zw
164
165	USE constants, &
166	ONLY: pi
167
168	USE control_parameters, &
169	ONLY: coupling_char, dt_3d, dz, message_string, simulated_time, &
170	wind_turbine, initializing_actions
171
172	USE cpulog, &
173	ONLY: cpu_log, log_point_s
174
175	USE grid_variables, &
176	ONLY: ddx, dx, ddy, dy
177
178	USE indices, &
179	ONLY: nbgp, nx, nxl, nxlg, nxr, nxrg, ny, nyn, nyng, nys, nysg, nz, &
180	nzb, nzt, wall_flags_0
181
182	USE kinds
183
184	USE pegrid
185
186
187	IMPLICIT NONE
188
189	PRIVATE
190
191	!
192	!-- Variables specified in the namelist wind_turbine_par
193
194	INTEGER(iwp) :: nairfoils = 8 !< number of airfoils of the used turbine model (for ADM-R and ALM)
195	INTEGER(iwp) :: nturbines = 1 !< number of turbines
196
197	LOGICAL :: pitch_control = .FALSE. !< switch for use of pitch controller
198	LOGICAL :: speed_control = .FALSE. !< switch for use of speed controller
199	LOGICAL :: yaw_control = .FALSE. !< switch for use of yaw controller
200	LOGICAL :: tl_cor = .FALSE. !< switch for use of tip loss correct.
201
202	REAL(wp) :: segment_length = 1.0_wp !< length of the segments, the rotor area is divided into
203	!< (in tangential direction, as factor of MIN(dx,dy,dz))
204	REAL(wp) :: segment_width = 0.5_wp !< width of the segments, the rotor area is divided into
205	!< (in radial direction, as factor of MIN(dx,dy,dz))
206	REAL(wp) :: time_turbine_on = 0.0_wp !< time at which turbines are started
207	REAL(wp) :: tilt = 0.0_wp !< vertical tilt of the rotor [degree] ( positive = backwards )
208
209	REAL(wp), DIMENSION(1:100) :: dtow = 0.0_wp !< tower diameter [m]
210	REAL(wp), DIMENSION(1:100) :: omega_rot = 0.9_wp !< inital or constant rotor speed [rad/s]
211	REAL(wp), DIMENSION(1:100) :: phi_yaw = 0.0_wp !< yaw angle [degree] ( clockwise, 0 = facing west )
212	REAL(wp), DIMENSION(1:100) :: pitch_add = 0.0_wp !< constant pitch angle
213	REAL(wp), DIMENSION(1:100) :: rcx = 9999999.9_wp !< position of hub in x-direction
214	REAL(wp), DIMENSION(1:100) :: rcy = 9999999.9_wp !< position of hub in y-direction
215	REAL(wp), DIMENSION(1:100) :: rcz = 9999999.9_wp !< position of hub in z-direction
216	REAL(wp), DIMENSION(1:100) :: rnac = 0.0_wp !< nacelle diameter [m]
217	REAL(wp), DIMENSION(1:100) :: rr = 63.0_wp !< rotor radius [m]
218	REAL(wp), DIMENSION(1:100) :: turb_cd_nacelle = 0.85_wp !< drag coefficient for nacelle
219	REAL(wp), DIMENSION(1:100) :: turb_cd_tower = 1.2_wp !< drag coefficient for tower
220
221	!
222	!-- Variables specified in the namelist for speed controller
223	!-- Default values are from the NREL 5MW research turbine (Jonkman, 2008)
224
225	REAL(wp) :: rated_power = 5296610.0_wp !< rated turbine power [W]
226	REAL(wp) :: gear_ratio = 97.0_wp !< Gear ratio from rotor to generator
227	REAL(wp) :: inertia_rot = 34784179.0_wp !< Inertia of the rotor [kg*m2]
228	REAL(wp) :: inertia_gen = 534.116_wp !< Inertia of the generator [kg*m2]
229	REAL(wp) :: gen_eff = 0.944_wp !< Electric efficiency of the generator
230	REAL(wp) :: gear_eff = 1.0_wp !< Loss between rotor and generator
231	REAL(wp) :: air_dens = 1.225_wp !< Air density to convert to W [kg/m3]
232	REAL(wp) :: rated_genspeed = 121.6805_wp !< Rated generator speed [rad/s]
233	REAL(wp) :: max_torque_gen = 47402.91_wp !< Maximum of the generator torque [Nm]
234	REAL(wp) :: slope2 = 2.332287_wp !< Slope constant for region 2
235	REAL(wp) :: min_reg2 = 91.21091_wp !< Lower generator speed boundary of region 2 [rad/s]
236	REAL(wp) :: min_reg15 = 70.16224_wp !< Lower generator speed boundary of region 1.5 [rad/s]
237	REAL(wp) :: max_trq_rate = 15000.0_wp !< Max generator torque increase [Nm/s]
238	REAL(wp) :: pitch_rate = 8.0_wp !< Max pitch rate [degree/s]
239
240
241	!
242	!-- Variables specified in the namelist for yaw control
243
244	REAL(wp) :: yaw_speed = 0.005236_wp !< speed of the yaw actuator [rad/s]
245	REAL(wp) :: max_miss = 0.08726_wp !< maximum tolerated yaw missalignment [rad]
246	REAL(wp) :: min_miss = 0.008726_wp !< minimum yaw missalignment for which the actuator stops [rad]
247
248	!
249	!-- Set flag for output files TURBINE_PARAMETERS
250	TYPE file_status
251	LOGICAL :: opened, opened_before
252	END TYPE file_status
253
254	TYPE(file_status), DIMENSION(500) :: openfile_turb_mod = &
255	file_status(.FALSE.,.FALSE.)
256
257	!
258	!-- Variables for initialization of the turbine model
259
260	INTEGER(iwp) :: inot !< turbine loop index (turbine id)
261	INTEGER(iwp) :: nsegs_max !< maximum number of segments (all turbines, required for allocation of arrays)
262	INTEGER(iwp) :: nrings_max !< maximum number of rings (all turbines, required for allocation of arrays)
263	INTEGER(iwp) :: ring !< ring loop index (ring number)
264	INTEGER(iwp) :: rr_int !<
265	INTEGER(iwp) :: upper_end !<
266
267	INTEGER(iwp), DIMENSION(1) :: lct !<
268
269	INTEGER(iwp), DIMENSION(:), ALLOCATABLE :: i_hub !< index belonging to x-position of the turbine
270	INTEGER(iwp), DIMENSION(:), ALLOCATABLE :: i_smear !< index defining the area for the smearing of the forces (x-direction)
271	INTEGER(iwp), DIMENSION(:), ALLOCATABLE :: j_hub !< index belonging to y-position of the turbine
272	INTEGER(iwp), DIMENSION(:), ALLOCATABLE :: j_smear !< index defining the area for the smearing of the forces (y-direction)
273	INTEGER(iwp), DIMENSION(:), ALLOCATABLE :: k_hub !< index belonging to hub height
274	INTEGER(iwp), DIMENSION(:), ALLOCATABLE :: k_smear !< index defining the area for the smearing of the forces (z-direction)
275	INTEGER(iwp), DIMENSION(:), ALLOCATABLE :: nrings !< number of rings per turbine
276	INTEGER(iwp), DIMENSION(:), ALLOCATABLE :: nsegs_total !< total number of segments per turbine
277
278	INTEGER(iwp), DIMENSION(:,:), ALLOCATABLE :: nsegs !< number of segments per ring and turbine
279
280	!
281	!- parameters for the smearing from the rotor to the cartesian grid
282	REAL(wp) :: pol_a !< parameter for the polynomial smearing fct
283	REAL(wp) :: pol_b !< parameter for the polynomial smearing fct
284	REAL(wp) :: delta_t_factor !<
285	REAL(wp) :: eps_factor !<
286	REAL(wp) :: eps_min !<
287	REAL(wp) :: eps_min2 !<
288	REAL(wp) :: sqrt_arg !<
289
290	!
291	!-- Variables for the calculation of lift and drag coefficients
292	REAL(wp), DIMENSION(:), ALLOCATABLE :: ard !<
293	REAL(wp), DIMENSION(:), ALLOCATABLE :: crd !<
294	REAL(wp), DIMENSION(:), ALLOCATABLE :: delta_r !< radial segment length
295	REAL(wp), DIMENSION(:), ALLOCATABLE :: lrd !<
296
297	REAL(wp) :: accu_cl_cd_tab = 0.1_wp !< Accuracy of the interpolation of
298	!< the lift and drag coeff [deg]
299
300	REAL(wp), DIMENSION(:,:), ALLOCATABLE :: turb_cd_tab !< table of the blade drag coefficient
301	REAL(wp), DIMENSION(:,:), ALLOCATABLE :: turb_cl_tab !< table of the blade lift coefficient
302
303	REAL(wp), DIMENSION(:,:,:), ALLOCATABLE :: nac_cd_surf !< 3d field of the tower drag coefficient
304	REAL(wp), DIMENSION(:,:,:), ALLOCATABLE :: tow_cd_surf !< 3d field of the nacelle drag coefficient
305
306	!
307	!-- Variables for the calculation of the forces
308
309	REAL(wp) :: cur_r !<
310	REAL(wp) :: phi_rotor !<
311	REAL(wp) :: pre_factor !<
312	REAL(wp) :: torque_seg !<
313	REAL(wp) :: u_int_l !<
314	REAL(wp) :: u_int_u !<
315	REAL(wp) :: u_rot !<
316	REAL(wp) :: v_int_l !<
317	REAL(wp) :: v_int_u !<
318	REAL(wp) :: w_int_l !<
319	REAL(wp) :: w_int_u !<
320	!
321	!- Tendencies from the nacelle and tower thrust
322	REAL(wp) :: tend_nac_x = 0.0_wp !<
323	REAL(wp) :: tend_tow_x = 0.0_wp !<
324	REAL(wp) :: tend_nac_y = 0.0_wp !<
325	REAL(wp) :: tend_tow_y = 0.0_wp !<
326
327	REAL(wp), DIMENSION(:), ALLOCATABLE :: alpha_attack !<
328	REAL(wp), DIMENSION(:), ALLOCATABLE :: chord !<
329	REAL(wp), DIMENSION(:), ALLOCATABLE :: phi_rel !<
330	REAL(wp), DIMENSION(:), ALLOCATABLE :: torque_total !<
331	REAL(wp), DIMENSION(:), ALLOCATABLE :: thrust_rotor !<
332	REAL(wp), DIMENSION(:), ALLOCATABLE :: turb_cl !<
333	REAL(wp), DIMENSION(:), ALLOCATABLE :: turb_cd !<
334	REAL(wp), DIMENSION(:), ALLOCATABLE :: vrel !<
335	REAL(wp), DIMENSION(:), ALLOCATABLE :: vtheta !<
336
337	REAL(wp), DIMENSION(:,:), ALLOCATABLE :: rbx, rby, rbz !< coordinates of the blade elements
338	REAL(wp), DIMENSION(:,:), ALLOCATABLE :: rotx, roty, rotz !< normal vectors to the rotor coordinates
339
340	!
341	!- Fields for the interpolation of velocities on the rotor grid
342	REAL(wp), DIMENSION(:,:,:), ALLOCATABLE :: u_int !<
343	REAL(wp), DIMENSION(:,:,:), ALLOCATABLE :: u_int_1_l !<
344	REAL(wp), DIMENSION(:,:,:), ALLOCATABLE :: v_int !<
345	REAL(wp), DIMENSION(:,:,:), ALLOCATABLE :: v_int_1_l !<
346	REAL(wp), DIMENSION(:,:,:), ALLOCATABLE :: w_int !<
347	REAL(wp), DIMENSION(:,:,:), ALLOCATABLE :: w_int_1_l !<
348
349	!
350	!- rotor tendencies on the segments
351	REAL(wp), DIMENSION(:), ALLOCATABLE :: thrust_seg !<
352	REAL(wp), DIMENSION(:), ALLOCATABLE :: torque_seg_y !<
353	REAL(wp), DIMENSION(:), ALLOCATABLE :: torque_seg_z !<
354
355	!
356	!- rotor tendencies on the rings
357	REAL(wp), DIMENSION(:,:), ALLOCATABLE :: thrust_ring !<
358	REAL(wp), DIMENSION(:,:), ALLOCATABLE :: torque_ring_y !<
359	REAL(wp), DIMENSION(:,:), ALLOCATABLE :: torque_ring_z !<
360
361	!
362	!- rotor tendencies on rotor grids for all turbines
363	REAL(wp), DIMENSION(:,:,:), ALLOCATABLE :: thrust !<
364	REAL(wp), DIMENSION(:,:,:), ALLOCATABLE :: torque_y !<
365	REAL(wp), DIMENSION(:,:,:), ALLOCATABLE :: torque_z !<
366
367	!
368	!- rotor tendencies on coordinate grid
369	REAL(wp), DIMENSION(:,:,:), ALLOCATABLE :: rot_tend_x !<
370	REAL(wp), DIMENSION(:,:,:), ALLOCATABLE :: rot_tend_y !<
371	REAL(wp), DIMENSION(:,:,:), ALLOCATABLE :: rot_tend_z !<
372	!
373	!- variables for the rotation of the rotor coordinates
374	REAL(wp), DIMENSION(1:100,1:3,1:3) :: rot_coord_trans !< matrix for rotation of rotor coordinates
375
376	REAL(wp), DIMENSION(1:3) :: rot_eigen_rad !<
377	REAL(wp), DIMENSION(1:3) :: rot_eigen_azi !<
378	REAL(wp), DIMENSION(1:3) :: rot_eigen_nor !<
379	REAL(wp), DIMENSION(1:3) :: re !<
380	REAL(wp), DIMENSION(1:3) :: rea !<
381	REAL(wp), DIMENSION(1:3) :: ren !<
382	REAL(wp), DIMENSION(1:3) :: rote !<
383	REAL(wp), DIMENSION(1:3) :: rota !<
384	REAL(wp), DIMENSION(1:3) :: rotn !<
385
386	!
387	!-- Fixed variables for the speed controller
388
389	LOGICAL :: start_up = .TRUE. !<
390
391	REAL(wp) :: Fcorner !< corner freq for the controller low pass filter
392	REAL(wp) :: min_reg25 !< min region 2.5
393	REAL(wp) :: om_rate !< rotor speed change
394	REAL(wp) :: slope15 !< slope in region 1.5
395	REAL(wp) :: slope25 !< slope in region 2.5
396	REAL(wp) :: trq_rate !< torque change
397	REAL(wp) :: vs_sysp !<
398	REAL(wp) :: lp_coeff !< coeff for the controller low pass filter
399
400	REAL(wp), DIMENSION(100) :: omega_rot_l = 0.0_wp !< local rot speed [rad/s]
401
402	!
403	!-- Fixed variables for the yaw controller
404
405	REAL(wp), DIMENSION(:) , ALLOCATABLE :: yawdir !< direction to yaw
406	REAL(wp), DIMENSION(:) , ALLOCATABLE :: phi_yaw_l !< local (cpu) yaw angle
407	REAL(wp), DIMENSION(:) , ALLOCATABLE :: wd30_l !< local (cpu) long running avg of the wd
408	REAL(wp), DIMENSION(:) , ALLOCATABLE :: wd2_l !< local (cpu) short running avg of the wd
409	REAL(wp), DIMENSION(:) , ALLOCATABLE :: wdir !< wind direction at hub
410	REAL(wp), DIMENSION(:) , ALLOCATABLE :: u_inflow !< wind speed at hub
411	REAL(wp), DIMENSION(:) , ALLOCATABLE :: wdir_l !<
412	REAL(wp), DIMENSION(:) , ALLOCATABLE :: u_inflow_l !<
413	REAL(wp), DIMENSION(:,:), ALLOCATABLE :: wd30 !<
414	REAL(wp), DIMENSION(:,:), ALLOCATABLE :: wd2 !<
415	LOGICAL, DIMENSION(1:100) :: doyaw = .FALSE. !<
416	INTEGER(iwp) :: WDLON !<
417	INTEGER(iwp) :: WDSHO !<
418
419	!
420	!-- Variables that have to be saved in the binary file for restarts
421	REAL(wp), DIMENSION(1:100) :: pitch_add_old = 0.0_wp !< old constant pitch angle
422	REAL(wp), DIMENSION(1:100) :: omega_gen = 0.0_wp !< curr. generator speed
423	REAL(wp), DIMENSION(1:100) :: omega_gen_f = 0.0_wp !< filtered generator speed
424	REAL(wp), DIMENSION(1:100) :: omega_gen_old = 0.0_wp !< last generator speed
425	REAL(wp), DIMENSION(1:100) :: omega_gen_f_old = 0.0_wp !< last filtered generator speed
426	REAL(wp), DIMENSION(1:100) :: torque_gen = 0.0_wp !< generator torque
427	REAL(wp), DIMENSION(1:100) :: torque_gen_old = 0.0_wp !< last generator torque
428
429
430	SAVE
431
432
433	INTERFACE wtm_parin
434	MODULE PROCEDURE wtm_parin
435	END INTERFACE wtm_parin
436
437	INTERFACE wtm_wrd_global
438	MODULE PROCEDURE wtm_wrd_global
439	END INTERFACE wtm_wrd_global
440
441	INTERFACE wtm_rrd_global
442	MODULE PROCEDURE wtm_rrd_global
443	END INTERFACE wtm_rrd_global
444
445	INTERFACE wtm_check_parameters
446	MODULE PROCEDURE wtm_check_parameters
447	END INTERFACE wtm_check_parameters
448
449	INTERFACE wtm_init_arrays
450	MODULE PROCEDURE wtm_init_arrays
451	END INTERFACE wtm_init_arrays
452
453	INTERFACE wtm_init
454	MODULE PROCEDURE wtm_init
455	END INTERFACE wtm_init
456
457	INTERFACE wtm_read_blade_tables
458	MODULE PROCEDURE wtm_read_blade_tables
459	END INTERFACE wtm_read_blade_tables
460
461	INTERFACE wtm_forces
462	MODULE PROCEDURE wtm_forces
463	END INTERFACE wtm_forces
464
465	INTERFACE wtm_yawcontrol
466	MODULE PROCEDURE wtm_yawcontrol
467	END INTERFACE wtm_yawcontrol
468
469	INTERFACE wtm_rotate_rotor
470	MODULE PROCEDURE wtm_rotate_rotor
471	END INTERFACE wtm_rotate_rotor
472
473	INTERFACE wtm_speed_control
474	MODULE PROCEDURE wtm_init_speed_control
475	MODULE PROCEDURE wtm_speed_control
476	END INTERFACE wtm_speed_control
477
478	INTERFACE wtm_tendencies
479	MODULE PROCEDURE wtm_tendencies
480	MODULE PROCEDURE wtm_tendencies_ij
481	END INTERFACE wtm_tendencies
482
483
484	PUBLIC wtm_check_parameters, wtm_forces, wtm_init, wtm_init_arrays, &
485	wtm_parin, wtm_wrd_global, wtm_rrd_global, wtm_tendencies
486
487
488	CONTAINS
489
490
491	!------------------------------------------------------------------------------!
492	! Description:
493	! ------------
494	!> Parin for &wind_turbine_par for wind turbine model
495	!------------------------------------------------------------------------------!
496	SUBROUTINE wtm_parin
497
498
499	IMPLICIT NONE
500
501	INTEGER(iwp) :: ierrn !<
502
503	CHARACTER (LEN=80) :: line !< dummy string that contains the current line of the parameter file
504
505	NAMELIST /wind_turbine_par/ air_dens, dtow, gear_eff, gear_ratio, &
506	gen_eff, inertia_gen, inertia_rot, max_miss, &
507	max_torque_gen, max_trq_rate, min_miss, &
508	min_reg15, min_reg2, nairfoils, nturbines, &
509	omega_rot, phi_yaw, pitch_add, pitch_control,&
510	rated_genspeed, rated_power, rcx, rcy, rcz, &
511	rnac, rr, segment_length, segment_width, &
512	slope2, speed_control, tilt, time_turbine_on,&
513	turb_cd_nacelle, turb_cd_tower, pitch_rate, &
514	yaw_control, yaw_speed, tl_cor
515
516	NAMELIST /wind_turbine_parameters/ &
517	air_dens, dtow, gear_eff, gear_ratio, &
518	gen_eff, inertia_gen, inertia_rot, max_miss, &
519	max_torque_gen, max_trq_rate, min_miss, &
520	min_reg15, min_reg2, nairfoils, nturbines, &
521	omega_rot, phi_yaw, pitch_add, pitch_control,&
522	rated_genspeed, rated_power, rcx, rcy, rcz, &
523	rnac, rr, segment_length, segment_width, &
524	slope2, speed_control, tilt, time_turbine_on,&
525	turb_cd_nacelle, turb_cd_tower, pitch_rate, &
526	yaw_control, yaw_speed, tl_cor
527	!
528	!-- Try to find wind turbine model package
529	REWIND ( 11 )
530	line = ' '
531	DO WHILE ( INDEX( line, '&wind_turbine_parameters' ) == 0 )
532	READ ( 11, '(A)', END=10 ) line
533	ENDDO
534	BACKSPACE ( 11 )
535
536	!
537	!-- Read user-defined namelist
538	READ ( 11, wind_turbine_parameters, IOSTAT=ierrn )
539
540	IF ( ierrn < 0 ) THEN
541	message_string = 'no wind_turbine_parameters-NAMELIST found: ' // &
542	'End of file has reached'
543	CALL message( 'wtm_parin', 'PA0460', 1, 2, 0, 6, 0 )
544	ELSEIF ( ierrn > 0 ) THEN
545	message_string = 'errors in wind_turbine_parameters-NAMELIST: ' // &
546	'some variables for steering may not be properly set'
547	CALL message( 'wtm_parin', 'PA0466', 1, 2, 0, 6, 0 )
548	ENDIF
549
550	!
551	!-- Set flag that indicates that the wind turbine model is switched on
552	wind_turbine = .TRUE.
553
554	GOTO 12
555
556	!
557	!-- Try to find wind turbine model package
558	10 REWIND ( 11 )
559	line = ' '
560	DO WHILE ( INDEX( line, '&wind_turbine_par' ) == 0 )
561	READ ( 11, '(A)', END=12 ) line
562	ENDDO
563	BACKSPACE ( 11 )
564
565	!
566	!-- Read user-defined namelist
567	READ ( 11, wind_turbine_par, IOSTAT=ierrn )
568
569	IF ( ierrn < 0 ) THEN
570	message_string = 'no wind_turbine_par-NAMELIST found: ' // &
571	'End of file has reached'
572	CALL message( 'wtm_parin', 'PA0460', 1, 2, 0, 6, 0 )
573	ELSEIF ( ierrn > 0 ) THEN
574	message_string = 'errors in wind_turbine_par-NAMELIST: ' // &
575	'some variables for steering may not be properly set'
576	CALL message( 'wtm_parin', 'PA0466', 1, 2, 0, 6, 0 )
577	ENDIF
578
579	message_string = 'namelist wind_tubrine_par is deprecated and will ' // &
580	'be removed in near future. &Please use namelist ' // &
581	'wind_turbine_parameters instead'
582	CALL message( 'wtm_parin', 'PA0487', 0, 1, 0, 6, 0 )
583
584	!
585	!-- Set flag that indicates that the wind turbine model is switched on
586	wind_turbine = .TRUE.
587
588	12 CONTINUE ! TBD Change from continue, mit ierrn machen
589
590
591	END SUBROUTINE wtm_parin
592
593
594	!------------------------------------------------------------------------------!
595	! Description:
596	! ------------
597	!> This routine writes the respective restart data.
598	!------------------------------------------------------------------------------!
599	SUBROUTINE wtm_wrd_global
600
601
602	IMPLICIT NONE
603
604
605	CALL wrd_write_string( 'omega_gen' )
606	WRITE ( 14 ) omega_gen
607
608	CALL wrd_write_string( 'omega_gen_f' )
609	WRITE ( 14 ) omega_gen_f
610
611	CALL wrd_write_string( 'omega_gen_f_old' )
612	WRITE ( 14 ) omega_gen_f_old
613
614	CALL wrd_write_string( 'omega_gen_old' )
615	WRITE ( 14 ) omega_gen_old
616
617	CALL wrd_write_string( 'omega_rot' )
618	WRITE ( 14 ) omega_rot
619
620	CALL wrd_write_string( 'phi_yaw' )
621	WRITE ( 14 ) phi_yaw
622
623	CALL wrd_write_string( 'pitch_add' )
624	WRITE ( 14 ) pitch_add
625
626	CALL wrd_write_string( 'pitch_add_old' )
627	WRITE ( 14 ) pitch_add_old
628
629	CALL wrd_write_string( 'torque_gen' )
630	WRITE ( 14 ) torque_gen
631
632	CALL wrd_write_string( 'torque_gen_old' )
633	WRITE ( 14 ) torque_gen_old
634
635
636	END SUBROUTINE wtm_wrd_global
637
638
639	!------------------------------------------------------------------------------!
640	! Description:
641	! ------------
642	!> This routine reads the respective restart data.
643	!------------------------------------------------------------------------------!
644	SUBROUTINE wtm_rrd_global( found )
645
646
647	USE control_parameters, &
648	ONLY: length, restart_string
649
650
651	IMPLICIT NONE
652
653	LOGICAL, INTENT(OUT) :: found
654
655
656	found = .TRUE.
657
658
659	SELECT CASE ( restart_string(1:length) )
660
661	CASE ( 'omega_gen' )
662	READ ( 13 ) omega_gen
663	CASE ( 'omega_gen_f' )
664	READ ( 13 ) omega_gen_f
665	CASE ( 'omega_gen_f_old' )
666	READ ( 13 ) omega_gen_f_old
667	CASE ( 'omega_gen_old' )
668	READ ( 13 ) omega_gen_old
669	CASE ( 'omega_rot' )
670	READ ( 13 ) omega_rot
671	CASE ( 'phi_yaw' )
672	READ ( 13 ) phi_yaw
673	CASE ( 'pitch_add' )
674	READ ( 13 ) pitch_add
675	CASE ( 'pitch_add_old' )
676	READ ( 13 ) pitch_add_old
677	CASE ( 'torque_gen' )
678	READ ( 13 ) torque_gen
679	CASE ( 'torque_gen_old' )
680	READ ( 13 ) torque_gen_old
681
682	CASE DEFAULT
683
684	found = .FALSE.
685
686	END SELECT
687
688
689	END SUBROUTINE wtm_rrd_global
690
691
692	!------------------------------------------------------------------------------!
693	! Description:
694	! ------------
695	!> Check namelist parameter
696	!------------------------------------------------------------------------------!
697	SUBROUTINE wtm_check_parameters
698
699
700	IMPLICIT NONE
701
702	IF ( ( .NOT.speed_control ) .AND. pitch_control ) THEN
703	message_string = 'pitch_control = .TRUE. requires '// &
704	'speed_control = .TRUE.'
705	CALL message( 'wtm_check_parameters', 'PA0461', 1, 2, 0, 6, 0 )
706	ENDIF
707
708	IF ( ANY( omega_rot(1:nturbines) < 0.0 ) ) THEN
709	message_string = 'omega_rot < 0.0, Please set omega_rot to ' // &
710	'a value equal or larger than zero'
711	CALL message( 'wtm_check_parameters', 'PA0462', 1, 2, 0, 6, 0 )
712	ENDIF
713
714
715	IF ( ANY( rcx(1:nturbines) == 9999999.9_wp ) .OR. &
716	ANY( rcy(1:nturbines) == 9999999.9_wp ) .OR. &
717	ANY( rcz(1:nturbines) == 9999999.9_wp ) ) THEN
718
719	message_string = 'rcx, rcy, rcz ' // &
720	'have to be given for each turbine.'
721	CALL message( 'wtm_check_parameters', 'PA0463', 1, 2, 0, 6, 0 )
722
723	ENDIF
724
725
726	END SUBROUTINE wtm_check_parameters
727
728
729	!------------------------------------------------------------------------------!
730	! Description:
731	! ------------
732	!> Allocate wind turbine model arrays
733	!------------------------------------------------------------------------------!
734	SUBROUTINE wtm_init_arrays
735
736
737	IMPLICIT NONE
738
739	REAL(wp) :: delta_r_factor !<
740	REAL(wp) :: delta_r_init !<
741
742	!
743	!-- To be able to allocate arrays with dimension of rotor rings and segments,
744	!-- the maximum possible numbers of rings and segments have to be calculated:
745
746	ALLOCATE( nrings(1:nturbines) )
747	ALLOCATE( delta_r(1:nturbines) )
748
749	nrings(:) = 0
750	delta_r(:) = 0.0_wp
751
752	!
753	!-- Thickness (radial) of each ring and length (tangential) of each segment:
754	delta_r_factor = segment_width
755	delta_t_factor = segment_length
756	delta_r_init = delta_r_factor * MIN( dx, dy, dz(1))
757
758	DO inot = 1, nturbines
759	!
760	!-- Determine number of rings:
761	nrings(inot) = NINT( rr(inot) / delta_r_init )
762
763	delta_r(inot) = rr(inot) / nrings(inot)
764
765	ENDDO
766
767	nrings_max = MAXVAL(nrings)
768
769	ALLOCATE( nsegs(1:nrings_max,1:nturbines) )
770	ALLOCATE( nsegs_total(1:nturbines) )
771
772	nsegs(:,:) = 0
773	nsegs_total(:) = 0
774
775
776	DO inot = 1, nturbines
777	DO ring = 1, nrings(inot)
778	!
779	!-- Determine number of segments for each ring:
780	nsegs(ring,inot) = MAX( 8, CEILING( delta_r_factor * pi * &
781	( 2.0_wp * ring - 1.0_wp ) / &
782	delta_t_factor ) )
783	ENDDO
784	!
785	!-- Total sum of all rotor segments:
786	nsegs_total(inot) = SUM( nsegs(:,inot) )
787
788	ENDDO
789
790	!
791	!-- Maximum number of segments per ring:
792	nsegs_max = MAXVAL(nsegs)
793
794	!!
795	!!-- TODO: Folgendes im Header ausgeben!
796	! IF ( myid == 0 ) THEN
797	! PRINT*, 'nrings(1) = ', nrings(1)
798	! PRINT*, '--------------------------------------------------'
799	! PRINT*, 'nsegs(:,1) = ', nsegs(:,1)
800	! PRINT*, '--------------------------------------------------'
801	! PRINT*, 'nrings_max = ', nrings_max
802	! PRINT*, 'nsegs_max = ', nsegs_max
803	! PRINT*, 'nsegs_total(1) = ', nsegs_total(1)
804	! ENDIF
805
806
807	!
808	!-- Allocate 1D arrays (dimension = number of turbines)
809	ALLOCATE( i_hub(1:nturbines) )
810	ALLOCATE( i_smear(1:nturbines) )
811	ALLOCATE( j_hub(1:nturbines) )
812	ALLOCATE( j_smear(1:nturbines) )
813	ALLOCATE( k_hub(1:nturbines) )
814	ALLOCATE( k_smear(1:nturbines) )
815	ALLOCATE( torque_total(1:nturbines) )
816	ALLOCATE( thrust_rotor(1:nturbines) )
817
818	!
819	!-- Allocation of the 1D arrays for yaw control
820	ALLOCATE( yawdir(1:nturbines) )
821	ALLOCATE( u_inflow(1:nturbines) )
822	ALLOCATE( wdir(1:nturbines) )
823	ALLOCATE( u_inflow_l(1:nturbines) )
824	ALLOCATE( wdir_l(1:nturbines) )
825	ALLOCATE( phi_yaw_l(1:nturbines) )
826
827	!
828	!-- Allocate 1D arrays (dimension = number of rotor segments)
829	ALLOCATE( alpha_attack(1:nsegs_max) )
830	ALLOCATE( chord(1:nsegs_max) )
831	ALLOCATE( phi_rel(1:nsegs_max) )
832	ALLOCATE( thrust_seg(1:nsegs_max) )
833	ALLOCATE( torque_seg_y(1:nsegs_max) )
834	ALLOCATE( torque_seg_z(1:nsegs_max) )
835	ALLOCATE( turb_cd(1:nsegs_max) )
836	ALLOCATE( turb_cl(1:nsegs_max) )
837	ALLOCATE( vrel(1:nsegs_max) )
838	ALLOCATE( vtheta(1:nsegs_max) )
839
840	!
841	!-- Allocate 2D arrays (dimension = number of rotor rings and segments)
842	ALLOCATE( rbx(1:nrings_max,1:nsegs_max) )
843	ALLOCATE( rby(1:nrings_max,1:nsegs_max) )
844	ALLOCATE( rbz(1:nrings_max,1:nsegs_max) )
845	ALLOCATE( thrust_ring(1:nrings_max,1:nsegs_max) )
846	ALLOCATE( torque_ring_y(1:nrings_max,1:nsegs_max) )
847	ALLOCATE( torque_ring_z(1:nrings_max,1:nsegs_max) )
848
849	!
850	!-- Allocate additional 2D arrays
851	ALLOCATE( rotx(1:nturbines,1:3) )
852	ALLOCATE( roty(1:nturbines,1:3) )
853	ALLOCATE( rotz(1:nturbines,1:3) )
854
855	!
856	!-- Allocate 3D arrays (dimension = number of grid points)
857	ALLOCATE( nac_cd_surf(nzb:nzt+1,nysg:nyng,nxlg:nxrg) )
858	ALLOCATE( rot_tend_x(nzb:nzt+1,nysg:nyng,nxlg:nxrg) )
859	ALLOCATE( rot_tend_y(nzb:nzt+1,nysg:nyng,nxlg:nxrg) )
860	ALLOCATE( rot_tend_z(nzb:nzt+1,nysg:nyng,nxlg:nxrg) )
861	ALLOCATE( thrust(nzb:nzt+1,nysg:nyng,nxlg:nxrg) )
862	ALLOCATE( torque_y(nzb:nzt+1,nysg:nyng,nxlg:nxrg) )
863	ALLOCATE( torque_z(nzb:nzt+1,nysg:nyng,nxlg:nxrg) )
864	ALLOCATE( tow_cd_surf(nzb:nzt+1,nysg:nyng,nxlg:nxrg) )
865
866	!
867	!-- Allocate additional 3D arrays
868	ALLOCATE( u_int(1:nturbines,1:nrings_max,1:nsegs_max) )
869	ALLOCATE( u_int_1_l(1:nturbines,1:nrings_max,1:nsegs_max) )
870	ALLOCATE( v_int(1:nturbines,1:nrings_max,1:nsegs_max) )
871	ALLOCATE( v_int_1_l(1:nturbines,1:nrings_max,1:nsegs_max) )
872	ALLOCATE( w_int(1:nturbines,1:nrings_max,1:nsegs_max) )
873	ALLOCATE( w_int_1_l(1:nturbines,1:nrings_max,1:nsegs_max) )
874
875	!
876	!-- All of the arrays are initialized with a value of zero:
877	i_hub(:) = 0
878	i_smear(:) = 0
879	j_hub(:) = 0
880	j_smear(:) = 0
881	k_hub(:) = 0
882	k_smear(:) = 0
883
884	torque_total(:) = 0.0_wp
885	thrust_rotor(:) = 0.0_wp
886
887	IF ( TRIM( initializing_actions ) /= 'read_restart_data' ) THEN
888	omega_gen(:) = 0.0_wp
889	omega_gen_old(:) = 0.0_wp
890	omega_gen_f(:) = 0.0_wp
891	omega_gen_f_old(:) = 0.0_wp
892	pitch_add_old(:) = 0.0_wp
893	torque_gen(:) = 0.0_wp
894	torque_gen_old(:) = 0.0_wp
895	ENDIF
896
897	yawdir(:) = 0.0_wp
898	wdir_l(:) = 0.0_wp
899	wdir(:) = 0.0_wp
900	u_inflow(:) = 0.0_wp
901	u_inflow_l(:) = 0.0_wp
902	phi_yaw_l(:) = 0.0_wp
903
904	!
905	!-- Allocate 1D arrays (dimension = number of rotor segments)
906	alpha_attack(:) = 0.0_wp
907	chord(:) = 0.0_wp
908	phi_rel(:) = 0.0_wp
909	thrust_seg(:) = 0.0_wp
910	torque_seg_y(:) = 0.0_wp
911	torque_seg_z(:) = 0.0_wp
912	turb_cd(:) = 0.0_wp
913	turb_cl(:) = 0.0_wp
914	vrel(:) = 0.0_wp
915	vtheta(:) = 0.0_wp
916
917	rbx(:,:) = 0.0_wp
918	rby(:,:) = 0.0_wp
919	rbz(:,:) = 0.0_wp
920	thrust_ring(:,:) = 0.0_wp
921	torque_ring_y(:,:) = 0.0_wp
922	torque_ring_z(:,:) = 0.0_wp
923
924	rotx(:,:) = 0.0_wp
925	roty(:,:) = 0.0_wp
926	rotz(:,:) = 0.0_wp
927
928	nac_cd_surf(:,:,:) = 0.0_wp
929	rot_tend_x(:,:,:) = 0.0_wp
930	rot_tend_y(:,:,:) = 0.0_wp
931	rot_tend_z(:,:,:) = 0.0_wp
932	thrust(:,:,:) = 0.0_wp
933	torque_y(:,:,:) = 0.0_wp
934	torque_z(:,:,:) = 0.0_wp
935	tow_cd_surf(:,:,:) = 0.0_wp
936
937	u_int(:,:,:) = 0.0_wp
938	u_int_1_l(:,:,:) = 0.0_wp
939	v_int(:,:,:) = 0.0_wp
940	v_int_1_l(:,:,:) = 0.0_wp
941	w_int(:,:,:) = 0.0_wp
942	w_int_1_l(:,:,:) = 0.0_wp
943
944
945	END SUBROUTINE wtm_init_arrays
946
947
948	!------------------------------------------------------------------------------!
949	! Description:
950	! ------------
951	!> Initialization of the wind turbine model
952	!------------------------------------------------------------------------------!
953	SUBROUTINE wtm_init
954
955
956	USE control_parameters, &
957	ONLY: dz_stretch_level_start
958
959	IMPLICIT NONE
960
961	INTEGER(iwp) :: i !< running index
962	INTEGER(iwp) :: j !< running index
963	INTEGER(iwp) :: k !< running index
964
965	!
966	!-- Help variables for the smearing function
967	REAL(wp) :: eps_kernel !<
968
969	!
970	!-- Help variables for calculation of the tower drag
971	INTEGER(iwp) :: tower_n !<
972	INTEGER(iwp) :: tower_s !<
973	!
974	!-- Help variables for the calulaction of the nacelle drag
975	INTEGER(iwp) :: i_ip !<
976	INTEGER(iwp) :: i_ipg !<
977
978	REAL(wp) :: yvalue
979	REAL(wp) :: dy_int !<
980	REAL(wp) :: dz_int !<
981
982	REAL(wp), DIMENSION(:,:), ALLOCATABLE :: circle_points !<
983
984	INTEGER(iwp), DIMENSION(:), ALLOCATABLE :: index_nacb !<
985	INTEGER(iwp), DIMENSION(:), ALLOCATABLE :: index_nacl !<
986	INTEGER(iwp), DIMENSION(:), ALLOCATABLE :: index_nacr !<
987	INTEGER(iwp), DIMENSION(:), ALLOCATABLE :: index_nact !<
988
989	ALLOCATE( index_nacb(1:nturbines) )
990	ALLOCATE( index_nacl(1:nturbines) )
991	ALLOCATE( index_nacr(1:nturbines) )
992	ALLOCATE( index_nact(1:nturbines) )
993
994	!
995	!------------------------------------------------------------------------------!
996	!-- Calculation of parameters for the regularization kernel
997	!-- (smearing of the forces)
998	!------------------------------------------------------------------------------!
999	!
1000	!-- In the following, some of the required parameters for the smearing will
1001	!-- be calculated:
1002
1003	!-- The kernel is set equal to twice the grid spacing which has turned out to
1004	!-- be a reasonable value (see e.g. Troldborg et al. (2013), Wind Energy,
1005	!-- DOI: 10.1002/we.1608):
1006	eps_kernel = 2.0_wp * dx
1007	!
1008	!-- The zero point (eps_min) of the polynomial function must be the following
1009	!-- if the integral of the polynomial function (for values < eps_min) shall
1010	!-- be equal to the integral of the Gaussian function used before:
1011	eps_min = ( 105.0_wp / 32.0_wp )*( 1.0_wp / 3.0_wp ) &
1012	pi*( 1.0_wp / 6.0_wp ) eps_kernel
1013	!
1014	!-- Stretching (non-uniform grid spacing) is not considered in the wind
1015	!-- turbine model. Therefore, vertical stretching has to be applied above
1016	!-- the area where the wtm is active. ABS (...) is required because the
1017	!-- default value of dz_stretch_level_start is -9999999.9_wp (negative).
1018	IF ( ABS( dz_stretch_level_start(1) ) <= MAXVAL(rcz) + MAXVAL(rr) + &
1019	eps_min) THEN
1020	WRITE( message_string, * ) 'The lowest level where vertical ', &
1021	'stretching is applied &have to be ', &
1022	'greater than ', MAXVAL(rcz) + &
1023	MAXVAL(rr) + eps_min
1024	CALL message( 'wtm_init', 'PA0484', 1, 2, 0, 6, 0 )
1025	ENDIF
1026	!
1027	!-- Square of eps_min:
1028	eps_min2 = eps_min**2
1029	!
1030	!-- Parameters in the polynomial function:
1031	pol_a = 1.0_wp / eps_min**4
1032	pol_b = 2.0_wp / eps_min**2
1033	!
1034	!-- Normalization factor which is the inverse of the integral of the smearing
1035	!-- function:
1036	eps_factor = 105.0_wp / ( 32.0_wp * pi * eps_min**3 )
1037
1038	!-- Change tilt angle to rad:
1039	tilt = tilt * pi / 180.0_wp
1040
1041	!
1042	!-- Change yaw angle to rad:
1043	IF ( TRIM( initializing_actions ) /= 'read_restart_data' ) THEN
1044	phi_yaw(:) = phi_yaw(:) * pi / 180.0_wp
1045	ENDIF
1046
1047
1048	DO inot = 1, nturbines
1049	!
1050	!-- Rotate the rotor coordinates in case yaw and tilt are defined
1051	CALL wtm_rotate_rotor( inot )
1052
1053	!
1054	!-- Determine the indices of the hub height
1055	i_hub(inot) = INT( rcx(inot) / dx )
1056	j_hub(inot) = INT( ( rcy(inot) + 0.5_wp * dy ) / dy )
1057	k_hub(inot) = INT( ( rcz(inot) + 0.5_wp * dz(1) ) / dz(1) )
1058
1059	!
1060	!-- Determining the area to which the smearing of the forces is applied.
1061	!-- As smearing now is effectively applied only for distances smaller than
1062	!-- eps_min, the smearing area can be further limited and regarded as a
1063	!-- function of eps_min:
1064	i_smear(inot) = CEILING( ( rr(inot) + eps_min ) / dx )
1065	j_smear(inot) = CEILING( ( rr(inot) + eps_min ) / dy )
1066	k_smear(inot) = CEILING( ( rr(inot) + eps_min ) / dz(1) )
1067
1068	ENDDO
1069
1070	!
1071	!-- Call the wtm_init_speed_control subroutine and calculate the local
1072	!-- omega_rot for the respective processor.
1073	IF ( speed_control) THEN
1074
1075	CALL wtm_speed_control
1076
1077	IF ( TRIM( initializing_actions ) == 'read_restart_data' ) THEN
1078
1079	DO inot = 1, nturbines
1080
1081	IF ( nxl > i_hub(inot) ) THEN
1082	torque_gen(inot) = 0.0_wp
1083	omega_gen_f(inot) = 0.0_wp
1084	omega_rot_l(inot) = 0.0_wp
1085	ENDIF
1086
1087	IF ( nxr < i_hub(inot) ) THEN
1088	torque_gen(inot) = 0.0_wp
1089	omega_gen_f(inot) = 0.0_wp
1090	omega_rot_l(inot) = 0.0_wp
1091	ENDIF
1092
1093	IF ( nys > j_hub(inot) ) THEN
1094	torque_gen(inot) = 0.0_wp
1095	omega_gen_f(inot) = 0.0_wp
1096	omega_rot_l(inot) = 0.0_wp
1097	ENDIF
1098
1099	IF ( nyn < j_hub(inot) ) THEN
1100	torque_gen(inot) = 0.0_wp
1101	omega_gen_f(inot) = 0.0_wp
1102	omega_rot_l(inot) = 0.0_wp
1103	ENDIF
1104
1105	IF ( ( nxl <= i_hub(inot) ) .AND. ( nxr >= i_hub(inot) ) ) THEN
1106	IF ( ( nys <= j_hub(inot) ) .AND. ( nyn >= j_hub(inot) ) ) THEN
1107
1108	omega_rot_l(inot) = omega_gen(inot) / gear_ratio
1109
1110	ENDIF
1111	ENDIF
1112
1113	END DO
1114
1115	ENDIF
1116
1117	ENDIF
1118
1119	!
1120	!------------------------------------------------------------------------------!
1121	!-- Determine the area within each grid cell that overlaps with the area
1122	!-- of the nacelle and the tower (needed for calculation of the forces)
1123	!------------------------------------------------------------------------------!
1124	!
1125	!-- Note: so far this is only a 2D version, in that the mean flow is
1126	!-- perpendicular to the rotor area.
1127
1128	!
1129	!-- Allocation of the array containing information on the intersection points
1130	!-- between rotor disk and the numerical grid:
1131	upper_end = ( ny + 1 ) * 10000
1132
1133	ALLOCATE( circle_points(1:2,1:upper_end) )
1134
1135	circle_points(:,:) = 0.0_wp
1136
1137
1138	DO inot = 1, nturbines ! loop over number of turbines
1139	!
1140	!-- Determine the grid index (u-grid) that corresponds to the location of
1141	!-- the rotor center (reduces the amount of calculations in the case that
1142	!-- the mean flow is perpendicular to the rotor area):
1143	i = i_hub(inot)
1144
1145	!
1146	!-- Determine the left and the right edge of the nacelle (corresponding
1147	!-- grid point indices):
1148	index_nacl(inot) = INT( ( rcy(inot) - rnac(inot) + 0.5_wp * dy ) / dy )
1149	index_nacr(inot) = INT( ( rcy(inot) + rnac(inot) + 0.5_wp * dy ) / dy )
1150	!
1151	!-- Determine the bottom and the top edge of the nacelle (corresponding
1152	!-- grid point indices).The grid point index has to be increased by 1, as
1153	!-- the first level for the u-component (index 0) is situated below the
1154	!-- surface. All points between z=0 and z=dz/s would already be contained
1155	!-- in grid box 1.
1156	index_nacb(inot) = INT( ( rcz(inot) - rnac(inot) ) / dz(1) ) + 1
1157	index_nact(inot) = INT( ( rcz(inot) + rnac(inot) ) / dz(1) ) + 1
1158
1159	!
1160	!-- Determine the indices of the grid boxes containing the left and
1161	!-- the right boundaries of the tower:
1162	tower_n = ( rcy(inot) + 0.5_wp * dtow(inot) - 0.5_wp * dy ) / dy
1163	tower_s = ( rcy(inot) - 0.5_wp * dtow(inot) - 0.5_wp * dy ) / dy
1164
1165	!
1166	!-- Determine the fraction of the grid box area overlapping with the tower
1167	!-- area and multiply it with the drag of the tower:
1168	IF ( ( nxlg <= i ) .AND. ( nxrg >= i ) ) THEN
1169
1170	DO j = nys, nyn
1171	!
1172	!-- Loop from south to north boundary of tower
1173	IF ( ( j >= tower_s ) .AND. ( j <= tower_n ) ) THEN
1174
1175	DO k = nzb, nzt
1176
1177	IF ( k == k_hub(inot) ) THEN
1178	IF ( tower_n - tower_s >= 1 ) THEN
1179	!
1180	!-- leftmost and rightmost grid box:
1181	IF ( j == tower_s ) THEN
1182	tow_cd_surf(k,j,i) = ( rcz(inot) - &
1183	( k_hub(inot) * dz(1) - 0.5_wp * dz(1) ) )*& ! extension in z-direction
1184	( ( tower_s + 1.0_wp + 0.5_wp ) * dy - &
1185	( rcy(inot) - 0.5_wp * dtow(inot) ) ) * & ! extension in y-direction
1186	turb_cd_tower(inot)
1187	ELSEIF ( j == tower_n ) THEN
1188	tow_cd_surf(k,j,i) = ( rcz(inot) - &
1189	( k_hub(inot) * dz(1) - 0.5_wp * dz(1) ) )*& ! extension in z-direction
1190	( ( rcy(inot) + 0.5_wp * dtow(inot) ) - &
1191	( tower_n + 0.5_wp ) * dy ) * & ! extension in y-direction
1192	turb_cd_tower(inot)
1193	!
1194	!-- grid boxes inbetween
1195	!-- (where tow_cd_surf = grid box area):
1196	ELSE
1197	tow_cd_surf(k,j,i) = ( rcz(inot) - &
1198	( k_hub(inot) * dz(1) - 0.5_wp * dz(1) ) )*&
1199	dy * turb_cd_tower(inot)
1200	ENDIF
1201	!
1202	!-- tower lies completely within one grid box:
1203	ELSE
1204	tow_cd_surf(k,j,i) = ( rcz(inot) - ( k_hub(inot) * &
1205	dz(1) - 0.5_wp * dz(1) ) ) * &
1206	dtow(inot) * turb_cd_tower(inot)
1207	ENDIF
1208	!
1209	!-- In case that k is smaller than k_hub the following actions
1210	!-- are carried out:
1211	ELSEIF ( k < k_hub(inot) ) THEN
1212
1213	IF ( ( tower_n - tower_s ) >= 1 ) THEN
1214	!
1215	!-- leftmost and rightmost grid box:
1216	IF ( j == tower_s ) THEN
1217	tow_cd_surf(k,j,i) = dz(1) * ( &
1218	( tower_s + 1 + 0.5_wp ) * dy - &
1219	( rcy(inot) - 0.5_wp * dtow(inot) ) &
1220	) * turb_cd_tower(inot)
1221	ELSEIF ( j == tower_n ) THEN
1222	tow_cd_surf(k,j,i) = dz(1) * ( &
1223	( rcy(inot) + 0.5_wp * dtow(inot) ) - &
1224	( tower_n + 0.5_wp ) * dy &
1225	) * turb_cd_tower(inot)
1226	!
1227	!-- grid boxes inbetween
1228	!-- (where tow_cd_surf = grid box area):
1229	ELSE
1230	tow_cd_surf(k,j,i) = dz(1) * dy * &
1231	turb_cd_tower(inot)
1232	ENDIF
1233	!
1234	!-- tower lies completely within one grid box:
1235	ELSE
1236	tow_cd_surf(k,j,i) = dz(1) * dtow(inot) * &
1237	turb_cd_tower(inot)
1238	ENDIF ! end if larger than grid box
1239
1240	ENDIF ! end if k == k_hub
1241
1242	ENDDO ! end loop over k
1243
1244	ENDIF ! end if inside north and south boundary of tower
1245
1246	ENDDO ! end loop over j
1247
1248	ENDIF ! end if hub inside domain + ghostpoints
1249
1250
1251	CALL exchange_horiz( tow_cd_surf, nbgp )
1252
1253	!
1254	!-- Calculation of the nacelle area
1255	!-- CAUTION: Currently disabled due to segmentation faults on the FLOW HPC
1256	!-- cluster (Oldenburg)
1257	!!
1258	!!-- Tabulate the points on the circle that are required in the following for
1259	!!-- the calculation of the Riemann integral (node points; they are called
1260	!!-- circle_points in the following):
1261	!
1262	! dy_int = dy / 10000.0_wp
1263	!
1264	! DO i_ip = 1, upper_end
1265	! yvalue = dy_int * ( i_ip - 0.5_wp ) + 0.5_wp * dy !<--- segmentation fault
1266	! sqrt_arg = rnac(inot)2 - ( yvalue - rcy(inot) )2 !<--- segmentation fault
1267	! IF ( sqrt_arg >= 0.0_wp ) THEN
1268	!!
1269	!!-- bottom intersection point
1270	! circle_points(1,i_ip) = rcz(inot) - SQRT( sqrt_arg )
1271	!!
1272	!!-- top intersection point
1273	! circle_points(2,i_ip) = rcz(inot) + SQRT( sqrt_arg ) !<--- segmentation fault
1274	! ELSE
1275	! circle_points(:,i_ip) = -111111 !<--- segmentation fault
1276	! ENDIF
1277	! ENDDO
1278	!
1279	!
1280	! DO j = nys, nyn
1281	!!
1282	!!-- In case that the grid box is located completely outside the nacelle
1283	!!-- (y) it can automatically be stated that there is no overlap between
1284	!!-- the grid box and the nacelle and consequently we can set
1285	!!-- nac_cd_surf(:,j,i) = 0.0:
1286	! IF ( ( j >= index_nacl(inot) ) .AND. ( j <= index_nacr(inot) ) ) THEN
1287	! DO k = nzb+1, nzt
1288	!!
1289	!!-- In case that the grid box is located completely outside the
1290	!!-- nacelle (z) it can automatically be stated that there is no
1291	!!-- overlap between the grid box and the nacelle and consequently
1292	!!-- we can set nac_cd_surf(k,j,i) = 0.0:
1293	! IF ( ( k >= index_nacb(inot) ) .OR. &
1294	! ( k <= index_nact(inot) ) ) THEN
1295	!!
1296	!!-- For all other cases Riemann integrals are calculated.
1297	!!-- Here, the points on the circle that have been determined
1298	!!-- above are used in order to calculate the overlap between the
1299	!!-- gridbox and the nacelle area (area approached by 10000
1300	!!-- rectangulars dz_int * dy_int):
1301	! DO i_ipg = 1, 10000
1302	! dz_int = dz
1303	! i_ip = j * 10000 + i_ipg
1304	!!
1305	!!-- Determine the vertical extension dz_int of the circle
1306	!!-- within the current grid box:
1307	! IF ( ( circle_points(2,i_ip) < zw(k) ) .AND. & !<--- segmentation fault
1308	! ( circle_points(2,i_ip) >= zw(k-1) ) ) THEN
1309	! dz_int = dz_int - & !<--- segmentation fault
1310	! ( zw(k) - circle_points(2,i_ip) )
1311	! ENDIF
1312	! IF ( ( circle_points(1,i_ip) <= zw(k) ) .AND. & !<--- segmentation fault
1313	! ( circle_points(1,i_ip) > zw(k-1) ) ) THEN
1314	! dz_int = dz_int - &
1315	! ( circle_points(1,i_ip) - zw(k-1) )
1316	! ENDIF
1317	! IF ( zw(k-1) > circle_points(2,i_ip) ) THEN
1318	! dz_int = 0.0_wp
1319	! ENDIF
1320	! IF ( zw(k) < circle_points(1,i_ip) ) THEN
1321	! dz_int = 0.0_wp
1322	! ENDIF
1323	! IF ( ( nxlg <= i ) .AND. ( nxrg >= i ) ) THEN
1324	! nac_cd_surf(k,j,i) = nac_cd_surf(k,j,i) + & !<--- segmentation fault
1325	! dy_int * dz_int * turb_cd_nacelle(inot)
1326	! ENDIF
1327	! ENDDO
1328	! ENDIF
1329	! ENDDO
1330	! ENDIF
1331	!
1332	! ENDDO
1333	!
1334	! CALL exchange_horiz( nac_cd_surf, nbgp ) !<--- segmentation fault
1335
1336	ENDDO ! end of loop over turbines
1337
1338	tow_cd_surf = tow_cd_surf / ( dx * dy * dz(1) ) ! Normalize tower drag
1339	nac_cd_surf = nac_cd_surf / ( dx * dy * dz(1) ) ! Normalize nacelle drag
1340
1341	CALL wtm_read_blade_tables
1342
1343	END SUBROUTINE wtm_init
1344
1345
1346	!------------------------------------------------------------------------------!
1347	! Description:
1348	! ------------
1349	!> Read in layout of the rotor blade , the lift and drag tables
1350	!> and the distribution of lift and drag tables along the blade
1351	!------------------------------------------------------------------------------!
1352	!
1353	SUBROUTINE wtm_read_blade_tables
1354
1355
1356	IMPLICIT NONE
1357
1358	INTEGER(iwp) :: ii !< running index
1359	INTEGER(iwp) :: jj !< running index
1360
1361	INTEGER(iwp) :: ierrn !<
1362
1363	CHARACTER(200) :: chmess !< Read in string
1364
1365	INTEGER(iwp) :: dlen !< no. rows of local table
1366	INTEGER(iwp) :: dlenbl !< no. rows of cd, cl table
1367	INTEGER(iwp) :: ialpha !< table position of current alpha value
1368	INTEGER(iwp) :: iialpha !<
1369	INTEGER(iwp) :: iir !<
1370	INTEGER(iwp) :: radres !< radial resolution
1371	INTEGER(iwp) :: t1 !< no. of airfoil
1372	INTEGER(iwp) :: t2 !< no. of airfoil
1373	INTEGER(iwp) :: trow !<
1374	INTEGER(iwp) :: dlenbl_int !< no. rows of interpolated cd, cl tables
1375
1376	REAL(wp) :: alpha_attack_i !<
1377	REAL(wp) :: weight_a !<
1378	REAL(wp) :: weight_b !<
1379
1380	INTEGER(iwp), DIMENSION(:), ALLOCATABLE :: ttoint1 !<
1381	INTEGER(iwp), DIMENSION(:), ALLOCATABLE :: ttoint2 !<
1382
1383	REAL(wp), DIMENSION(:), ALLOCATABLE :: turb_cd_sel1 !<
1384	REAL(wp), DIMENSION(:), ALLOCATABLE :: turb_cd_sel2 !<
1385	REAL(wp), DIMENSION(:), ALLOCATABLE :: turb_cl_sel1 !<
1386	REAL(wp), DIMENSION(:), ALLOCATABLE :: turb_cl_sel2 !<
1387	REAL(wp), DIMENSION(:), ALLOCATABLE :: read_cl_cd !< read in var array
1388
1389	REAL(wp), DIMENSION(:), ALLOCATABLE :: alpha_attack_tab !<
1390	REAL(wp), DIMENSION(:), ALLOCATABLE :: trad1 !<
1391	REAL(wp), DIMENSION(:), ALLOCATABLE :: trad2 !<
1392	REAL(wp), DIMENSION(:,:), ALLOCATABLE :: turb_cd_table !<
1393	REAL(wp), DIMENSION(:,:), ALLOCATABLE :: turb_cl_table !<
1394
1395	ALLOCATE ( read_cl_cd(1:2*nairfoils+1) )
1396
1397	!
1398	!-- Read in the distribution of lift and drag tables along the blade, the
1399	!-- layout of the rotor blade and the lift and drag tables:
1400
1401	OPEN ( 90, FILE='WTM_DATA', STATUS='OLD', FORM='FORMATTED', IOSTAT=ierrn )
1402
1403	IF ( ierrn /= 0 ) THEN
1404	message_string = 'file WTM_DATA does not exist'
1405	CALL message( 'wtm_init', 'PA0464', 1, 2, 0, 6, 0 )
1406	ENDIF
1407	!
1408	!-- Read distribution table:
1409
1410	dlen = 0
1411
1412	READ ( 90, '(3/)' )
1413
1414	rloop3: DO
1415	READ ( 90, *, IOSTAT=ierrn ) chmess
1416	IF ( ierrn < 0 .OR. chmess == '#' .OR. chmess == '') EXIT rloop3
1417	dlen = dlen + 1
1418	ENDDO rloop3
1419
1420	ALLOCATE( trad1(1:dlen), trad2(1:dlen), ttoint1(1:dlen), ttoint2(1:dlen))
1421
1422	DO jj = 1,dlen+1
1423	BACKSPACE ( 90, IOSTAT=ierrn )
1424	ENDDO
1425
1426	DO jj = 1,dlen
1427	READ ( 90, * ) trad1(jj), trad2(jj), ttoint1(jj), ttoint2(jj)
1428	ENDDO
1429
1430	!
1431	!-- Read layout table:
1432
1433	dlen = 0
1434
1435	READ ( 90, '(3/)')
1436
1437	rloop1: DO
1438	READ ( 90, *, IOSTAT=ierrn ) chmess
1439	IF ( ierrn < 0 .OR. chmess == '#' .OR. chmess == '') EXIT rloop1
1440	dlen = dlen + 1
1441	ENDDO rloop1
1442
1443	ALLOCATE( lrd(1:dlen), ard(1:dlen), crd(1:dlen) )
1444	DO jj = 1, dlen+1
1445	BACKSPACE ( 90, IOSTAT=ierrn )
1446	ENDDO
1447	DO jj = 1, dlen
1448	READ ( 90, * ) lrd(jj), ard(jj), crd(jj)
1449	ENDDO
1450
1451	!
1452	!-- Read tables (turb_cl(alpha),turb_cd(alpha) for the different profiles:
1453
1454	dlen = 0
1455
1456	READ ( 90, '(3/)' )
1457
1458	rloop2: DO
1459	READ ( 90, *, IOSTAT=ierrn ) chmess
1460	IF ( ierrn < 0 .OR. chmess == '#' .OR. chmess == '') EXIT rloop2
1461	dlen = dlen + 1
1462	ENDDO rloop2
1463
1464	ALLOCATE( alpha_attack_tab(1:dlen), turb_cl_table(1:dlen,1:nairfoils), &
1465	turb_cd_table(1:dlen,1:nairfoils) )
1466
1467	DO jj = 1,dlen+1
1468	BACKSPACE ( 90, IOSTAT=ierrn )
1469	ENDDO
1470
1471	DO jj = 1,dlen
1472	READ ( 90, * ) read_cl_cd
1473	alpha_attack_tab(jj) = read_cl_cd(1)
1474	DO ii= 1, nairfoils
1475	turb_cl_table(jj,ii) = read_cl_cd(ii*2)
1476	turb_cd_table(jj,ii) = read_cl_cd(ii*2+1)
1477	ENDDO
1478
1479	ENDDO
1480
1481	dlenbl = dlen
1482
1483	CLOSE ( 90 )
1484
1485	!
1486	!-- For each possible radial position (resolution: 0.1 m --> 631 values if rr(1)=63m)
1487	!-- and each possible angle of attack (resolution: 0.1 degrees --> 3601 values!)
1488	!-- determine the lift and drag coefficient by interpolating between the
1489	!-- tabulated values of each table (interpolate to current angle of attack)
1490	!-- and between the tables (interpolate to current radial position):
1491
1492	ALLOCATE( turb_cl_sel1(1:dlenbl) )
1493	ALLOCATE( turb_cl_sel2(1:dlenbl) )
1494	ALLOCATE( turb_cd_sel1(1:dlenbl) )
1495	ALLOCATE( turb_cd_sel2(1:dlenbl) )
1496
1497	radres = INT( rr(1) * 10.0_wp ) + 1_iwp
1498	dlenbl_int = INT( 360.0_wp / accu_cl_cd_tab ) + 1_iwp
1499
1500	ALLOCATE( turb_cl_tab(1:dlenbl_int,1:radres) )
1501	ALLOCATE( turb_cd_tab(1:dlenbl_int,1:radres) )
1502
1503	DO iir = 1, radres ! loop over radius
1504
1505	cur_r = ( iir - 1_iwp ) * 0.1_wp
1506	!
1507	!-- Find position in table 1
1508	lct = MINLOC( ABS( trad1 - cur_r ) )
1509	! lct(1) = lct(1)
1510
1511	IF ( ( trad1(lct(1)) - cur_r ) .GT. 0.0 ) THEN
1512	lct(1) = lct(1) - 1
1513	ENDIF
1514
1515	trow = lct(1)
1516	!
1517	!-- Calculate weights for radius interpolation
1518	weight_a = ( trad2(trow) - cur_r ) / ( trad2(trow) - trad1(trow) )
1519	weight_b = ( cur_r - trad1(trow) ) / ( trad2(trow) - trad1(trow) )
1520	t1 = ttoint1(trow)
1521	t2 = ttoint2(trow)
1522
1523	IF ( t1 .EQ. t2 ) THEN ! if both are the same, the weights are NaN
1524	weight_a = 0.5_wp ! then do interpolate in between same twice
1525	weight_b = 0.5_wp ! using 0.5 as weight
1526	ENDIF
1527
1528	IF ( t1 == 0 .AND. t2 == 0 ) THEN
1529	turb_cd_sel1 = 0.0_wp
1530	turb_cd_sel2 = 0.0_wp
1531	turb_cl_sel1 = 0.0_wp
1532	turb_cl_sel2 = 0.0_wp
1533
1534	turb_cd_tab(1,iir) = 0.0_wp ! For -180Â° (iialpha=1) the values
1535	turb_cl_tab(1,iir) = 0.0_wp ! for each radius has to be set
1536	! explicitly
1537	ELSE
1538	turb_cd_sel1 = turb_cd_table(:,t1)
1539	turb_cd_sel2 = turb_cd_table(:,t2)
1540	turb_cl_sel1 = turb_cl_table(:,t1)
1541	turb_cl_sel2 = turb_cl_table(:,t2)
1542	!
1543	!-- For -180Â° (iialpha=1) the values for each radius has to be set
1544	!-- explicitly
1545	turb_cd_tab(1,iir) = ( weight_a * turb_cd_table(1,t1) + weight_b &
1546	* turb_cd_table(1,t2) )
1547	turb_cl_tab(1,iir) = ( weight_a * turb_cl_table(1,t1) + weight_b &
1548	* turb_cl_table(1,t2) )
1549	ENDIF
1550
1551	DO iialpha = 2, dlenbl_int ! loop over angles
1552
1553	alpha_attack_i = -180.0_wp + REAL( iialpha-1 ) * accu_cl_cd_tab
1554	ialpha = 1
1555
1556	DO WHILE ( ( alpha_attack_i > alpha_attack_tab(ialpha) ) .AND. (ialpha <= dlen ) )
1557	ialpha = ialpha + 1
1558	ENDDO
1559
1560	!
1561	!-- Interpolation of lift and drag coefficiencts on fine grid of radius
1562	!-- segments and angles of attack
1563	turb_cl_tab(iialpha,iir) = ( alpha_attack_tab(ialpha) - &
1564	alpha_attack_i ) / &
1565	( alpha_attack_tab(ialpha) - &
1566	alpha_attack_tab(ialpha-1) ) * &
1567	( weight_a * turb_cl_sel1(ialpha-1) + &
1568	weight_b * turb_cl_sel2(ialpha-1) ) +&
1569	( alpha_attack_i - &
1570	alpha_attack_tab(ialpha-1) ) / &
1571	( alpha_attack_tab(ialpha) - &
1572	alpha_attack_tab(ialpha-1) ) * &
1573	( weight_a * turb_cl_sel1(ialpha) + &
1574	weight_b * turb_cl_sel2(ialpha) )
1575	turb_cd_tab(iialpha,iir) = ( alpha_attack_tab(ialpha) - &
1576	alpha_attack_i ) / &
1577	( alpha_attack_tab(ialpha) - &
1578	alpha_attack_tab(ialpha-1) ) * &
1579	( weight_a * turb_cd_sel1(ialpha-1) + &
1580	weight_b * turb_cd_sel2(ialpha-1) ) +&
1581	( alpha_attack_i - &
1582	alpha_attack_tab(ialpha-1) ) / &
1583	( alpha_attack_tab(ialpha) - &
1584	alpha_attack_tab(ialpha-1) ) * &
1585	( weight_a * turb_cd_sel1(ialpha) + &
1586	weight_b * turb_cd_sel2(ialpha) )
1587
1588	ENDDO ! end loop over angles of attack
1589
1590	ENDDO ! end loop over radius
1591
1592
1593	END SUBROUTINE wtm_read_blade_tables
1594
1595
1596	!------------------------------------------------------------------------------!
1597	! Description:
1598	! ------------
1599	!> The projection matrix for the coordinate system of therotor disc in respect
1600	!> to the yaw and tilt angle of the rotor is calculated
1601	!------------------------------------------------------------------------------!
1602	SUBROUTINE wtm_rotate_rotor( inot )
1603
1604
1605	IMPLICIT NONE
1606
1607	INTEGER(iwp) :: inot
1608	!
1609	!-- Calculation of the rotation matrix for the application of the tilt to
1610	!-- the rotors
1611	rot_eigen_rad(1) = SIN( phi_yaw(inot) ) ! x-component of the radial eigenvector
1612	rot_eigen_rad(2) = COS( phi_yaw(inot) ) ! y-component of the radial eigenvector
1613	rot_eigen_rad(3) = 0.0_wp ! z-component of the radial eigenvector
1614
1615	rot_eigen_azi(1) = 0.0_wp ! x-component of the azimuth eigenvector
1616	rot_eigen_azi(2) = 0.0_wp ! y-component of the azimuth eigenvector
1617	rot_eigen_azi(3) = 1.0_wp ! z-component of the azimuth eigenvector
1618
1619	rot_eigen_nor(1) = COS( phi_yaw(inot) ) ! x-component of the normal eigenvector
1620	rot_eigen_nor(2) = -SIN( phi_yaw(inot) ) ! y-component of the normal eigenvector
1621	rot_eigen_nor(3) = 0.0_wp ! z-component of the normal eigenvector
1622
1623	!
1624	!-- Calculation of the coordinate transformation matrix to apply a tilt to
1625	!-- the rotor. If tilt = 0, rot_coord_trans is a unit matrix.
1626
1627	rot_coord_trans(inot,1,1) = rot_eigen_rad(1)*2 &
1628	( 1.0_wp - COS( tilt ) ) + COS( tilt )
1629	rot_coord_trans(inot,1,2) = rot_eigen_rad(1) * rot_eigen_rad(2) * &
1630	( 1.0_wp - COS( tilt ) ) - &
1631	rot_eigen_rad(3) * SIN( tilt )
1632	rot_coord_trans(inot,1,3) = rot_eigen_rad(1) * rot_eigen_rad(3) * &
1633	( 1.0_wp - COS( tilt ) ) + &
1634	rot_eigen_rad(2) * SIN( tilt )
1635	rot_coord_trans(inot,2,1) = rot_eigen_rad(2) * rot_eigen_rad(1) * &
1636	( 1.0_wp - COS( tilt ) ) + &
1637	rot_eigen_rad(3) * SIN( tilt )
1638	rot_coord_trans(inot,2,2) = rot_eigen_rad(2)*2 &
1639	( 1.0_wp - COS( tilt ) ) + COS( tilt )
1640	rot_coord_trans(inot,2,3) = rot_eigen_rad(2) * rot_eigen_rad(3) * &
1641	( 1.0_wp - COS( tilt ) ) - &
1642	rot_eigen_rad(1) * SIN( tilt )
1643	rot_coord_trans(inot,3,1) = rot_eigen_rad(3) * rot_eigen_rad(1) * &
1644	( 1.0_wp - COS( tilt ) ) - &
1645	rot_eigen_rad(2) * SIN( tilt )
1646	rot_coord_trans(inot,3,2) = rot_eigen_rad(3) * rot_eigen_rad(2) * &
1647	( 1.0_wp - COS( tilt ) ) + &
1648	rot_eigen_rad(1) * SIN( tilt )
1649	rot_coord_trans(inot,3,3) = rot_eigen_rad(3)*2 &
1650	( 1.0_wp - COS( tilt ) ) + COS( tilt )
1651
1652	!
1653	!-- Vectors for the Transformation of forces from the rotor's spheric
1654	!-- coordinate system to the cartesian coordinate system
1655	rotx(inot,:) = MATMUL( rot_coord_trans(inot,:,:), rot_eigen_nor )
1656	roty(inot,:) = MATMUL( rot_coord_trans(inot,:,:), rot_eigen_rad )
1657	rotz(inot,:) = MATMUL( rot_coord_trans(inot,:,:), rot_eigen_azi )
1658
1659	END SUBROUTINE wtm_rotate_rotor
1660
1661
1662	!------------------------------------------------------------------------------!
1663	! Description:
1664	! ------------
1665	!> Calculation of the forces generated by the wind turbine
1666	!------------------------------------------------------------------------------!
1667	SUBROUTINE wtm_forces
1668
1669
1670	IMPLICIT NONE
1671
1672	CHARACTER (LEN=4) :: turbine_id
1673
1674	INTEGER(iwp) :: i, j, k !< loop indices
1675	INTEGER(iwp) :: inot !< turbine loop index (turbine id)
1676	INTEGER(iwp) :: iialpha, iir !<
1677	INTEGER(iwp) :: rseg, rseg_int !<
1678	INTEGER(iwp) :: ring, ring_int !<
1679	INTEGER(iwp) :: ii, jj, kk !<
1680
1681	REAL(wp) :: flag !< flag to mask topography grid points
1682	REAL(wp) :: sin_rot, cos_rot !<
1683	REAL(wp) :: sin_yaw, cos_yaw !<
1684
1685	REAL(wp) :: aa, bb, cc, dd !< interpolation distances
1686	REAL(wp) :: gg !< interpolation volume var
1687
1688	REAL(wp) :: dist_u_3d, dist_v_3d, dist_w_3d !< smearing distances
1689
1690
1691	!
1692	! Variables for pitch control
1693	REAL(wp) :: torque_max=0.0_wp
1694	LOGICAL :: pitch_sw=.FALSE.
1695
1696	INTEGER(iwp), DIMENSION(1) :: lct=0
1697	REAL(wp), DIMENSION(1) :: rad_d=0.0_wp
1698
1699	REAL(wp) :: tl_factor !< factor for tip loss correction
1700
1701
1702	CALL cpu_log( log_point_s(61), 'wtm_forces', 'start' )
1703
1704
1705	IF ( simulated_time >= time_turbine_on ) THEN
1706
1707	!
1708	!-- Set forces to zero for each new time step:
1709	thrust(:,:,:) = 0.0_wp
1710	torque_y(:,:,:) = 0.0_wp
1711	torque_z(:,:,:) = 0.0_wp
1712	torque_total(:) = 0.0_wp
1713	rot_tend_x(:,:,:) = 0.0_wp
1714	rot_tend_y(:,:,:) = 0.0_wp
1715	rot_tend_z(:,:,:) = 0.0_wp
1716	thrust_rotor(:) = 0.0_wp
1717	!
1718	!-- Loop over number of turbines:
1719	DO inot = 1, nturbines
1720
1721	cos_yaw = COS(phi_yaw(inot))
1722	sin_yaw = SIN(phi_yaw(inot))
1723	!
1724	!-- Loop over rings of each turbine:
1725	DO ring = 1, nrings(inot)
1726
1727	thrust_seg(:) = 0.0_wp
1728	torque_seg_y(:) = 0.0_wp
1729	torque_seg_z(:) = 0.0_wp
1730	!
1731	!-- Determine distance between each ring (center) and the hub:
1732	cur_r = (ring - 0.5_wp) * delta_r(inot)
1733
1734	!
1735	!-- Loop over segments of each ring of each turbine:
1736	DO rseg = 1, nsegs(ring,inot)
1737	!
1738	!-- !-----------------------------------------------------------!
1739	!-- !-- Determine coordinates of the ring segments --!
1740	!-- !-----------------------------------------------------------!
1741	!
1742	!-- Determine angle of ring segment towards zero degree angle of
1743	!-- rotor system (at zero degree rotor direction vectors aligned
1744	!-- with y-axis):
1745	phi_rotor = rseg * 2.0_wp * pi / nsegs(ring,inot)
1746	cos_rot = COS( phi_rotor )
1747	sin_rot = SIN( phi_rotor )
1748
1749	!-- Now the direction vectors can be determined with respect to
1750	!-- the yaw and tilt angle:
1751	re(1) = cos_rot * sin_yaw
1752	re(2) = cos_rot * cos_yaw
1753	re(3) = sin_rot
1754
1755	rote = MATMUL( rot_coord_trans(inot,:,:), re )
1756	!
1757	!-- Coordinates of the single segments (center points):
1758	rbx(ring,rseg) = rcx(inot) + cur_r * rote(1)
1759	rby(ring,rseg) = rcy(inot) + cur_r * rote(2)
1760	rbz(ring,rseg) = rcz(inot) + cur_r * rote(3)
1761
1762	!-- !-----------------------------------------------------------!
1763	!-- !-- Interpolation of the velocity components from the --!
1764	!-- !-- cartesian grid point to the coordinates of each ring --!
1765	!-- !-- segment (follows a method used in the particle model) --!
1766	!-- !-----------------------------------------------------------!
1767
1768	u_int(inot,ring,rseg) = 0.0_wp
1769	u_int_1_l(inot,ring,rseg) = 0.0_wp
1770
1771	v_int(inot,ring,rseg) = 0.0_wp
1772	v_int_1_l(inot,ring,rseg) = 0.0_wp
1773
1774	w_int(inot,ring,rseg) = 0.0_wp
1775	w_int_1_l(inot,ring,rseg) = 0.0_wp
1776
1777	!
1778	!-- Interpolation of the u-component:
1779
1780	ii = rbx(ring,rseg) * ddx
1781	jj = ( rby(ring,rseg) - 0.5_wp * dy ) * ddy
1782	kk = ( rbz(ring,rseg) + 0.5_wp * dz(1) ) / dz(1)
1783	!
1784	!-- Interpolate only if all required information is available on
1785	!-- the current PE:
1786	IF ( ( ii >= nxl ) .AND. ( ii <= nxr ) ) THEN
1787	IF ( ( jj >= nys ) .AND. ( jj <= nyn ) ) THEN
1788
1789	aa = ( ( ii + 1 ) * dx - rbx(ring,rseg) ) * &
1790	( ( jj + 1 + 0.5_wp ) * dy - rby(ring,rseg) )
1791	bb = ( rbx(ring,rseg) - ii * dx ) * &
1792	( ( jj + 1 + 0.5_wp ) * dy - rby(ring,rseg) )
1793	cc = ( ( ii+1 ) * dx - rbx(ring,rseg) ) * &
1794	( rby(ring,rseg) - ( jj + 0.5_wp ) * dy )
1795	dd = ( rbx(ring,rseg) - ii * dx ) * &
1796	( rby(ring,rseg) - ( jj + 0.5_wp ) * dy )
1797	gg = dx * dy
1798
1799	u_int_l = ( aa * u(kk,jj,ii) + &
1800	bb * u(kk,jj,ii+1) + &
1801	cc * u(kk,jj+1,ii) + &
1802	dd * u(kk,jj+1,ii+1) &
1803	) / gg
1804
1805	u_int_u = ( aa * u(kk+1,jj,ii) + &
1806	bb * u(kk+1,jj,ii+1) + &
1807	cc * u(kk+1,jj+1,ii) + &
1808	dd * u(kk+1,jj+1,ii+1) &
1809	) / gg
1810
1811	u_int_1_l(inot,ring,rseg) = u_int_l + &
1812	( rbz(ring,rseg) - zu(kk) ) / dz(1) * &
1813	( u_int_u - u_int_l )
1814
1815	ELSE
1816	u_int_1_l(inot,ring,rseg) = 0.0_wp
1817	ENDIF
1818	ELSE
1819	u_int_1_l(inot,ring,rseg) = 0.0_wp
1820	ENDIF
1821
1822
1823	!
1824	!-- Interpolation of the v-component:
1825	ii = ( rbx(ring,rseg) - 0.5_wp * dx ) * ddx
1826	jj = rby(ring,rseg) * ddy
1827	kk = ( rbz(ring,rseg) + 0.5_wp * dz(1) ) / dz(1)
1828	!
1829	!-- Interpolate only if all required information is available on
1830	!-- the current PE:
1831	IF ( ( ii >= nxl ) .AND. ( ii <= nxr ) ) THEN
1832	IF ( ( jj >= nys ) .AND. ( jj <= nyn ) ) THEN
1833
1834	aa = ( ( ii + 1 + 0.5_wp ) * dx - rbx(ring,rseg) ) * &
1835	( ( jj + 1 ) * dy - rby(ring,rseg) )
1836	bb = ( rbx(ring,rseg) - ( ii + 0.5_wp ) * dx ) * &
1837	( ( jj + 1 ) * dy - rby(ring,rseg) )
1838	cc = ( ( ii + 1 + 0.5_wp ) * dx - rbx(ring,rseg) ) * &
1839	( rby(ring,rseg) - jj * dy )
1840	dd = ( rbx(ring,rseg) - ( ii + 0.5_wp ) * dx ) * &
1841	( rby(ring,rseg) - jj * dy )
1842	gg = dx * dy
1843
1844	v_int_l = ( aa * v(kk,jj,ii) + &
1845	bb * v(kk,jj,ii+1) + &
1846	cc * v(kk,jj+1,ii) + &
1847	dd * v(kk,jj+1,ii+1) &
1848	) / gg
1849
1850	v_int_u = ( aa * v(kk+1,jj,ii) + &
1851	bb * v(kk+1,jj,ii+1) + &
1852	cc * v(kk+1,jj+1,ii) + &
1853	dd * v(kk+1,jj+1,ii+1) &
1854	) / gg
1855
1856	v_int_1_l(inot,ring,rseg) = v_int_l + &
1857	( rbz(ring,rseg) - zu(kk) ) / dz(1) * &
1858	( v_int_u - v_int_l )
1859
1860	ELSE
1861	v_int_1_l(inot,ring,rseg) = 0.0_wp
1862	ENDIF
1863	ELSE
1864	v_int_1_l(inot,ring,rseg) = 0.0_wp
1865	ENDIF
1866
1867
1868	!
1869	!-- Interpolation of the w-component:
1870	ii = ( rbx(ring,rseg) - 0.5_wp * dx ) * ddx
1871	jj = ( rby(ring,rseg) - 0.5_wp * dy ) * ddy
1872	kk = rbz(ring,rseg) / dz(1)
1873	!
1874	!-- Interpolate only if all required information is available on
1875	!-- the current PE:
1876	IF ( ( ii >= nxl ) .AND. ( ii <= nxr ) ) THEN
1877	IF ( ( jj >= nys ) .AND. ( jj <= nyn ) ) THEN
1878
1879	aa = ( ( ii + 1 + 0.5_wp ) * dx - rbx(ring,rseg) ) * &
1880	( ( jj + 1 + 0.5_wp ) * dy - rby(ring,rseg) )
1881	bb = ( rbx(ring,rseg) - ( ii + 0.5_wp ) * dx ) * &
1882	( ( jj + 1 + 0.5_wp ) * dy - rby(ring,rseg) )
1883	cc = ( ( ii + 1 + 0.5_wp ) * dx - rbx(ring,rseg) ) * &
1884	( rby(ring,rseg) - ( jj + 0.5_wp ) * dy )
1885	dd = ( rbx(ring,rseg) - ( ii + 0.5_wp ) * dx ) * &
1886	( rby(ring,rseg) - ( jj + 0.5_wp ) * dy )
1887	gg = dx * dy
1888
1889	w_int_l = ( aa * w(kk,jj,ii) + &
1890	bb * w(kk,jj,ii+1) + &
1891	cc * w(kk,jj+1,ii) + &
1892	dd * w(kk,jj+1,ii+1) &
1893	) / gg
1894
1895	w_int_u = ( aa * w(kk+1,jj,ii) + &
1896	bb * w(kk+1,jj,ii+1) + &
1897	cc * w(kk+1,jj+1,ii) + &
1898	dd * w(kk+1,jj+1,ii+1) &
1899	) / gg
1900
1901	w_int_1_l(inot,ring,rseg) = w_int_l + &
1902	( rbz(ring,rseg) - zw(kk) ) / dz(1) * &
1903	( w_int_u - w_int_l )
1904	ELSE
1905	w_int_1_l(inot,ring,rseg) = 0.0_wp
1906	ENDIF
1907	ELSE
1908	w_int_1_l(inot,ring,rseg) = 0.0_wp
1909	ENDIF
1910
1911	ENDDO
1912	ENDDO
1913
1914	ENDDO
1915
1916	!
1917	!-- Exchange between PEs (information required on each PE):
1918	#if defined( __parallel )
1919	CALL MPI_ALLREDUCE( u_int_1_l, u_int, nturbines * MAXVAL(nrings) * &
1920	MAXVAL(nsegs), MPI_REAL, MPI_SUM, comm2d, ierr )
1921	CALL MPI_ALLREDUCE( v_int_1_l, v_int, nturbines * MAXVAL(nrings) * &
1922	MAXVAL(nsegs), MPI_REAL, MPI_SUM, comm2d, ierr )
1923	CALL MPI_ALLREDUCE( w_int_1_l, w_int, nturbines * MAXVAL(nrings) * &
1924	MAXVAL(nsegs), MPI_REAL, MPI_SUM, comm2d, ierr )
1925	#else
1926	u_int = u_int_1_l
1927	v_int = v_int_1_l
1928	w_int = w_int_1_l
1929	#endif
1930
1931
1932	!
1933	!-- Loop over number of turbines:
1934
1935	DO inot = 1, nturbines
1936	pit_loop: DO
1937
1938	IF ( pitch_sw ) THEN
1939	torque_total(inot) = 0.0_wp
1940	thrust_rotor(inot) = 0.0_wp
1941	pitch_add(inot) = pitch_add(inot) + 0.25_wp
1942	! IF ( myid == 0 ) PRINT*, 'Pitch', inot, pitch_add(inot)
1943	ELSE
1944	cos_yaw = COS(phi_yaw(inot))
1945	sin_yaw = SIN(phi_yaw(inot))
1946	IF ( pitch_control ) THEN
1947	pitch_add(inot) = MAX(pitch_add_old(inot) - pitch_rate * &
1948	dt_3d , 0.0_wp )
1949	ENDIF
1950	ENDIF
1951
1952	!
1953	!-- Loop over rings of each turbine:
1954	DO ring = 1, nrings(inot)
1955	!
1956	!-- Determine distance between each ring (center) and the hub:
1957	cur_r = (ring - 0.5_wp) * delta_r(inot)
1958	!
1959	!-- Loop over segments of each ring of each turbine:
1960	DO rseg = 1, nsegs(ring,inot)
1961	!
1962	!-- Determine angle of ring segment towards zero degree angle of
1963	!-- rotor system (at zero degree rotor direction vectors aligned
1964	!-- with y-axis):
1965	phi_rotor = rseg * 2.0_wp * pi / nsegs(ring,inot)
1966	cos_rot = COS(phi_rotor)
1967	sin_rot = SIN(phi_rotor)
1968	!
1969	!-- Now the direction vectors can be determined with respect to
1970	!-- the yaw and tilt angle:
1971	re(1) = cos_rot * sin_yaw
1972	re(2) = cos_rot * cos_yaw
1973	re(3) = sin_rot
1974
1975	! The current unit vector in azimuthal direction:
1976	rea(1) = - sin_rot * sin_yaw
1977	rea(2) = - sin_rot * cos_yaw
1978	rea(3) = cos_rot
1979
1980	!
1981	!-- To respect the yawing angle for the calculations of
1982	!-- velocities and forces the unit vectors perpendicular to the
1983	!-- rotor area in direction of the positive yaw angle are defined:
1984	ren(1) = cos_yaw
1985	ren(2) = - sin_yaw
1986	ren(3) = 0.0_wp
1987	!
1988	!-- Multiplication with the coordinate transformation matrix
1989	!-- gives the final unit vector with consideration of the rotor
1990	!-- tilt:
1991	rote = MATMUL( rot_coord_trans(inot,:,:), re )
1992	rota = MATMUL( rot_coord_trans(inot,:,:), rea )
1993	rotn = MATMUL( rot_coord_trans(inot,:,:), ren )
1994	!
1995	!-- Coordinates of the single segments (center points):
1996	rbx(ring,rseg) = rcx(inot) + cur_r * rote(1)
1997
1998	rby(ring,rseg) = rcy(inot) + cur_r * rote(2)
1999
2000	rbz(ring,rseg) = rcz(inot) + cur_r * rote(3)
2001
2002	!
2003	!-- !-----------------------------------------------------------!
2004	!-- !-- Calculation of various angles and relative velocities --!
2005	!-- !-----------------------------------------------------------!
2006	!
2007	!-- In the following the 3D-velocity field is projected its
2008	!-- components perpendicular and parallel to the rotor area
2009	!-- The calculation of forces will be done in the rotor-
2010	!-- coordinates y' and z.
2011	!-- The yaw angle will be reintroduced when the force is applied
2012	!-- on the hydrodynamic equations
2013	!
2014	!-- Projection of the xy-velocities relative to the rotor area
2015	!
2016	!-- Velocity perpendicular to the rotor area:
2017	u_rot = u_int(inot,ring,rseg)*rotn(1) + &
2018	v_int(inot,ring,rseg)*rotn(2) + &
2019	w_int(inot,ring,rseg)*rotn(3)
2020	!
2021	!-- Projection of the 3D-velocity vector in the azimuthal
2022	!-- direction:
2023	vtheta(rseg) = rota(1) * u_int(inot,ring,rseg) + &
2024	rota(2) * v_int(inot,ring,rseg) + &
2025	rota(3) * w_int(inot,ring,rseg)
2026	!
2027	!-- Determination of the angle phi_rel between the rotor plane
2028	!-- and the direction of the flow relative to the rotor:
2029
2030	phi_rel(rseg) = ATAN( u_rot / &
2031	( omega_rot(inot) * cur_r - &
2032	vtheta(rseg) ) )
2033
2034	!
2035	!-- Interpolation of the local pitch angle from tabulated values
2036	!-- to the current radial position:
2037
2038	lct=minloc(ABS(cur_r-lrd))
2039	rad_d=cur_r-lrd(lct)
2040
2041	IF (cur_r == 0.0_wp) THEN
2042	alpha_attack(rseg) = 0.0_wp
2043	ELSE IF (cur_r >= lrd(size(ard))) THEN
2044	alpha_attack(rseg) = ( ard(size(ard)) + &
2045	ard(size(ard)-1) ) / 2.0_wp
2046	ELSE
2047	alpha_attack(rseg) = ( ard(lct(1)) * &
2048	( ( lrd(lct(1)+1) - cur_r ) / &
2049	( lrd(lct(1)+1) - lrd(lct(1)) ) &
2050	) ) + ( ard(lct(1)+1) * &
2051	( ( cur_r - lrd(lct(1)) ) / &
2052	( lrd(lct(1)+1) - lrd(lct(1)) ) ) )
2053	ENDIF
2054
2055	!
2056	!-- In Fortran radian instead of degree is used as unit for all
2057	!-- angles. Therefore, a transformation from angles given in
2058	!-- degree to angles given in radian is necessary here:
2059	alpha_attack(rseg) = alpha_attack(rseg) * &
2060	( (2.0_wp*pi) / 360.0_wp )
2061	!
2062	!-- Substraction of the local pitch angle to obtain the local
2063	!-- angle of attack:
2064	alpha_attack(rseg) = phi_rel(rseg) - alpha_attack(rseg)
2065	!
2066	!-- Preliminary transformation back from angles given in radian
2067	!-- to angles given in degree:
2068	alpha_attack(rseg) = alpha_attack(rseg) * &
2069	( 360.0_wp / (2.0_wp*pi) )
2070	!
2071	!-- Correct with collective pitch angle:
2072	alpha_attack(rseg) = alpha_attack(rseg) - pitch_add(inot)
2073
2074	!
2075	!-- Determination of the magnitude of the flow velocity relative
2076	!-- to the rotor:
2077	vrel(rseg) = SQRT( u_rot**2 + &
2078	( omega_rot(inot) * cur_r - &
2079	vtheta(rseg) )**2 )
2080
2081	!
2082	!-- !-----------------------------------------------------------!
2083	!-- !-- Interpolation of chord as well as lift and drag --!
2084	!-- !-- coefficients from tabulated values --!
2085	!-- !-----------------------------------------------------------!
2086
2087	!
2088	!-- Interpolation of the chord_length from tabulated values to
2089	!-- the current radial position:
2090
2091	IF (cur_r == 0.0_wp) THEN
2092	chord(rseg) = 0.0_wp
2093	ELSE IF (cur_r >= lrd(size(crd))) THEN
2094	chord(rseg) = (crd(size(crd)) + ard(size(crd)-1)) / 2.0_wp
2095	ELSE
2096	chord(rseg) = ( crd(lct(1)) * &
2097	( ( lrd(lct(1)+1) - cur_r ) / &
2098	( lrd(lct(1)+1) - lrd(lct(1)) ) ) ) + &
2099	( crd(lct(1)+1) * &
2100	( ( cur_r-lrd(lct(1)) ) / &
2101	( lrd(lct(1)+1) - lrd(lct(1)) ) ) )
2102	ENDIF
2103
2104	!
2105	!-- Determine index of current angle of attack, needed for
2106	!-- finding the appropriate interpolated values of the lift and
2107	!-- drag coefficients (-180.0 degrees = 1, +180.0 degrees = 3601,
2108	!-- so one index every 0.1 degrees):
2109	iialpha = CEILING( ( alpha_attack(rseg) + 180.0_wp ) &
2110	* ( 1.0_wp / accu_cl_cd_tab ) ) + 1.0_wp
2111	!
2112	!-- Determine index of current radial position, needed for
2113	!-- finding the appropriate interpolated values of the lift and
2114	!-- drag coefficients (one index every 0.1 m):
2115	iir = CEILING( cur_r * 10.0_wp )
2116	!
2117	!-- Read in interpolated values of the lift and drag coefficients
2118	!-- for the current radial position and angle of attack:
2119	turb_cl(rseg) = turb_cl_tab(iialpha,iir)
2120	turb_cd(rseg) = turb_cd_tab(iialpha,iir)
2121
2122	!
2123	!-- Final transformation back from angles given in degree to
2124	!-- angles given in radian:
2125	alpha_attack(rseg) = alpha_attack(rseg) * &
2126	( (2.0_wp*pi) / 360.0_wp )
2127
2128	IF ( tl_cor ) THEN
2129
2130	!-- Tip loss correction following Schito
2131	!-- Schito applies the tip loss correction only to the lift force
2132	!-- Therefore, the tip loss correction is only applied to the lift
2133	!-- coefficient and not to the drag coefficient in our case
2134	!--
2135	tl_factor = ( 2.0 / pi ) * &
2136	ACOS( EXP( -1.0 * ( 3.0 * ( rr(inot) - cur_r ) / &
2137	( 2.0 * cur_r * abs( sin( phi_rel(rseg) ) ) ) ) ) )
2138
2139	turb_cl(rseg) = tl_factor * turb_cl(rseg)
2140
2141	ENDIF
2142	!
2143	!-- !-----------------------------------------------------!
2144	!-- !-- Calculation of the forces --!
2145	!-- !-----------------------------------------------------!
2146
2147	!
2148	!-- Calculate the pre_factor for the thrust and torque forces:
2149
2150	pre_factor = 0.5_wp * (vrel(rseg)*2) 3.0_wp * &
2151	chord(rseg) * delta_r(inot) / nsegs(ring,inot)
2152
2153	!
2154	!-- Calculate the thrust force (x-component of the total force)
2155	!-- for each ring segment:
2156	thrust_seg(rseg) = pre_factor * &
2157	( turb_cl(rseg) * COS(phi_rel(rseg)) + &
2158	turb_cd(rseg) * SIN(phi_rel(rseg)) )
2159
2160	!
2161	!-- Determination of the second of the additional forces acting
2162	!-- on the flow in the azimuthal direction: force vector as basis
2163	!-- for torque (torque itself would be the vector product of the
2164	!-- radius vector and the force vector):
2165	torque_seg = pre_factor * &
2166	( turb_cl(rseg) * SIN(phi_rel(rseg)) - &
2167	turb_cd(rseg) * COS(phi_rel(rseg)) )
2168	!
2169	!-- Decomposition of the force vector into two parts:
2170	!-- One acting along the y-direction and one acting along the
2171	!-- z-direction of the rotor coordinate system:
2172
2173	torque_seg_y(rseg) = -torque_seg * sin_rot
2174	torque_seg_z(rseg) = torque_seg * cos_rot
2175
2176	!
2177	!-- Add the segment thrust to the thrust of the whole rotor
2178	thrust_rotor(inot) = thrust_rotor(inot) + &
2179	thrust_seg(rseg)
2180
2181
2182	torque_total(inot) = torque_total(inot) + (torque_seg * cur_r)
2183
2184	ENDDO !-- end of loop over ring segments
2185
2186	!
2187	!-- Restore the forces into arrays containing all the segments of
2188	!-- each ring:
2189	thrust_ring(ring,:) = thrust_seg(:)
2190	torque_ring_y(ring,:) = torque_seg_y(:)
2191	torque_ring_z(ring,:) = torque_seg_z(:)
2192
2193
2194	ENDDO !-- end of loop over rings
2195
2196
2197	CALL cpu_log( log_point_s(62), 'wtm_controller', 'start' )
2198
2199
2200	IF ( speed_control ) THEN
2201	!
2202	!-- Calculation of the current generator speed for rotor speed control
2203
2204	!
2205	!-- The acceleration of the rotor speed is calculated from
2206	!-- the force balance of the accelerating torque
2207	!-- and the torque of the rotating rotor and generator
2208	om_rate = ( torque_total(inot) * air_dens * gear_eff - &
2209	gear_ratio * torque_gen_old(inot) ) / &
2210	( inertia_rot + &
2211	gear_ratio * gear_ratio * inertia_gen ) * dt_3d
2212
2213	!
2214	!-- The generator speed is given by the product of gear gear_ratio
2215	!-- and rotor speed
2216	omega_gen(inot) = gear_ratio * ( omega_rot(inot) + om_rate )
2217
2218	ENDIF
2219
2220	IF ( pitch_control ) THEN
2221
2222	!
2223	!-- If the current generator speed is above rated, the pitch is not
2224	!-- saturated and the change from the last time step is within the
2225	!-- maximum pitch rate, then the pitch loop is repeated with a pitch
2226	!-- gain
2227	IF ( ( omega_gen(inot) > rated_genspeed ) .AND. &
2228	( pitch_add(inot) < 25.0_wp ) .AND. &
2229	( pitch_add(inot) < pitch_add_old(inot) + &
2230	pitch_rate * dt_3d ) ) THEN
2231	pitch_sw = .TRUE.
2232	!
2233	!-- Go back to beginning of pit_loop
2234	CYCLE pit_loop
2235	ENDIF
2236
2237	!
2238	!-- The current pitch is saved for the next time step
2239	pitch_add_old(inot) = pitch_add(inot)
2240	pitch_sw = .FALSE.
2241	ENDIF
2242	EXIT pit_loop
2243	ENDDO pit_loop ! Recursive pitch control loop
2244
2245
2246	!
2247	!-- Call the rotor speed controller
2248
2249	IF ( speed_control ) THEN
2250	!
2251	!-- Find processor at i_hub, j_hub
2252	IF ( ( nxl <= i_hub(inot) ) .AND. ( nxr >= i_hub(inot) ) ) &
2253	THEN
2254	IF ( ( nys <= j_hub(inot) ) .AND. ( nyn >= j_hub(inot) ) )&
2255	THEN
2256	CALL wtm_speed_control( inot )
2257	ENDIF
2258	ENDIF
2259
2260	ENDIF
2261
2262
2263	CALL cpu_log( log_point_s(62), 'wtm_controller', 'stop' )
2264
2265	CALL cpu_log( log_point_s(63), 'wtm_smearing', 'start' )
2266
2267
2268	!-- !-----------------------------------------------------------------!
2269	!-- !-- Regularization kernel --!
2270	!-- !-- Smearing of the forces and interpolation to cartesian grid --!
2271	!-- !-----------------------------------------------------------------!
2272	!
2273	!-- The aerodynamic blade forces need to be distributed smoothly on
2274	!-- several mesh points in order to avoid singular behaviour
2275	!
2276	!-- Summation over sum of weighted forces. The weighting factor
2277	!-- (calculated in user_init) includes information on the distance
2278	!-- between the center of the grid cell and the rotor segment under
2279	!-- consideration
2280	!
2281	!-- To save computing time, apply smearing only for the relevant part
2282	!-- of the model domain:
2283	!
2284	!--
2285	!-- Calculation of the boundaries:
2286	i_smear(inot) = CEILING( ( rr(inot) * ABS( roty(inot,1) ) + &
2287	eps_min ) / dx )
2288	j_smear(inot) = CEILING( ( rr(inot) * ABS( roty(inot,2) ) + &
2289	eps_min ) / dy )
2290
2291	DO i = MAX( nxl, i_hub(inot) - i_smear(inot) ), &
2292	MIN( nxr, i_hub(inot) + i_smear(inot) )
2293	DO j = MAX( nys, j_hub(inot) - j_smear(inot) ), &
2294	MIN( nyn, j_hub(inot) + j_smear(inot) )
2295	! DO k = MAX( nzb_u_inner(j,i)+1, k_hub(inot) - k_smear(inot) ), &
2296	! k_hub(inot) + k_smear(inot)
2297	DO k = nzb+1, k_hub(inot) + k_smear(inot)
2298	DO ring = 1, nrings(inot)
2299	DO rseg = 1, nsegs(ring,inot)
2300	!
2301	!-- Predetermine flag to mask topography
2302	flag = MERGE( 1.0_wp, 0.0_wp, BTEST( wall_flags_0(k,j,i), 1 ) )
2303
2304	!
2305	!-- Determine the square of the distance between the
2306	!-- current grid point and each rotor area segment:
2307	dist_u_3d = ( i * dx - rbx(ring,rseg) )**2 + &
2308	( j * dy + 0.5_wp * dy - rby(ring,rseg) )**2 + &
2309	( k * dz(1) - 0.5_wp * dz(1) - rbz(ring,rseg) )**2
2310	dist_v_3d = ( i * dx + 0.5_wp * dx - rbx(ring,rseg) )**2 + &
2311	( j * dy - rby(ring,rseg) )**2 + &
2312	( k * dz(1) - 0.5_wp * dz(1) - rbz(ring,rseg) )**2
2313	dist_w_3d = ( i * dx + 0.5_wp * dx - rbx(ring,rseg) )**2 + &
2314	( j * dy + 0.5_wp * dy - rby(ring,rseg) )**2 + &
2315	( k * dz(1) - rbz(ring,rseg) )**2
2316
2317	!
2318	!-- 3D-smearing of the forces with a polynomial function
2319	!-- (much faster than the old Gaussian function), using
2320	!-- some parameters that have been calculated in user_init.
2321	!-- The function is only similar to Gaussian function for
2322	!-- squared distances <= eps_min2:
2323	IF ( dist_u_3d <= eps_min2 ) THEN
2324	thrust(k,j,i) = thrust(k,j,i) + &
2325	thrust_ring(ring,rseg) * &
2326	( ( pol_a * dist_u_3d - pol_b ) * &
2327	dist_u_3d + 1.0_wp ) * eps_factor *&
2328	flag
2329	ENDIF
2330	IF ( dist_v_3d <= eps_min2 ) THEN
2331	torque_y(k,j,i) = torque_y(k,j,i) + &
2332	torque_ring_y(ring,rseg) * &
2333	( ( pol_a * dist_v_3d - pol_b ) * &
2334	dist_v_3d + 1.0_wp ) * eps_factor * &
2335	flag
2336	ENDIF
2337	IF ( dist_w_3d <= eps_min2 ) THEN
2338	torque_z(k,j,i) = torque_z(k,j,i) + &
2339	torque_ring_z(ring,rseg) * &
2340	( ( pol_a * dist_w_3d - pol_b ) * &
2341	dist_w_3d + 1.0_wp ) * eps_factor * &
2342	flag
2343	ENDIF
2344
2345	ENDDO ! End of loop over rseg
2346	ENDDO ! End of loop over ring
2347
2348	!
2349	!-- Rotation of force components:
2350	rot_tend_x(k,j,i) = rot_tend_x(k,j,i) + ( &
2351	thrust(k,j,i)*rotx(inot,1) + &
2352	torque_y(k,j,i)*roty(inot,1) + &
2353	torque_z(k,j,i)*rotz(inot,1) &
2354	) * flag
2355
2356	rot_tend_y(k,j,i) = rot_tend_y(k,j,i) + ( &
2357	thrust(k,j,i)*rotx(inot,2) + &
2358	torque_y(k,j,i)*roty(inot,2) + &
2359	torque_z(k,j,i)*rotz(inot,2) &
2360	) * flag
2361
2362	rot_tend_z(k,j,i) = rot_tend_z(k,j,i) + ( &
2363	thrust(k,j,i)*rotx(inot,3) + &
2364	torque_y(k,j,i)*roty(inot,3) + &
2365	torque_z(k,j,i)*rotz(inot,3) &
2366	) * flag
2367
2368	ENDDO ! End of loop over k
2369	ENDDO ! End of loop over j
2370	ENDDO ! End of loop over i
2371
2372	CALL cpu_log( log_point_s(63), 'wtm_smearing', 'stop' )
2373
2374	ENDDO !-- end of loop over turbines
2375
2376
2377	IF ( yaw_control ) THEN
2378	!
2379	!-- Allocate arrays for yaw control at first call
2380	!-- Can't be allocated before dt_3d is set
2381	IF ( start_up ) THEN
2382	WDLON = NINT( 30.0_wp / dt_3d ) ! 30s running mean array
2383	ALLOCATE( wd30(1:nturbines,1:WDLON) )
2384	wd30 = 999.0_wp ! Set to dummy value
2385	ALLOCATE( wd30_l(1:WDLON) )
2386
2387	WDSHO = NINT( 2.0_wp / dt_3d ) ! 2s running mean array
2388	ALLOCATE( wd2(1:nturbines,1:WDSHO) )
2389	wd2 = 999.0_wp ! Set to dummy value
2390	ALLOCATE( wd2_l(1:WDSHO) )
2391	start_up = .FALSE.
2392	ENDIF
2393
2394	!
2395	!-- Calculate the inflow wind speed
2396	!--
2397	!-- Loop over number of turbines:
2398	DO inot = 1, nturbines
2399	!
2400	!-- Find processor at i_hub, j_hub
2401	IF ( ( nxl <= i_hub(inot) ) .AND. ( nxr >= i_hub(inot) ) ) &
2402	THEN
2403	IF ( ( nys <= j_hub(inot) ) .AND. ( nyn >= j_hub(inot) ) )&
2404	THEN
2405
2406	u_inflow_l(inot) = u(k_hub(inot),j_hub(inot),i_hub(inot))
2407
2408	wdir_l(inot) = -1.0_wp * ATAN2( &
2409	0.5_wp * ( v(k_hub(inot),j_hub(inot),i_hub(inot)+1) + &
2410	v(k_hub(inot),j_hub(inot),i_hub(inot)) ) , &
2411	0.5_wp * ( u(k_hub(inot),j_hub(inot)+1,i_hub(inot)) + &
2412	u(k_hub(inot),j_hub(inot),i_hub(inot)) ) )
2413
2414	CALL wtm_yawcontrol( inot )
2415
2416	phi_yaw_l(inot) = phi_yaw(inot)
2417
2418	ENDIF
2419	ENDIF
2420
2421	ENDDO !-- end of loop over turbines
2422
2423	!
2424	!-- Transfer of information to the other cpus
2425	#if defined( __parallel )
2426	CALL MPI_ALLREDUCE( u_inflow_l, u_inflow, nturbines, MPI_REAL, &
2427	MPI_SUM, comm2d, ierr )
2428	CALL MPI_ALLREDUCE( wdir_l, wdir, nturbines, MPI_REAL, MPI_SUM, &
2429	comm2d, ierr )
2430	CALL MPI_ALLREDUCE( phi_yaw_l, phi_yaw, nturbines, MPI_REAL, &
2431	MPI_SUM, comm2d, ierr )
2432	#else
2433	u_inflow = u_inflow_l
2434	wdir = wdir_l
2435	phi_yaw = phi_yaw_l
2436
2437
2438	#endif
2439	DO inot = 1, nturbines
2440	!
2441	!-- Update rotor orientation
2442	CALL wtm_rotate_rotor( inot )
2443
2444	ENDDO ! End of loop over turbines
2445
2446	ENDIF ! end of yaw control
2447
2448	IF ( speed_control ) THEN
2449	!
2450	!-- Transfer of information to the other cpus
2451	! CALL MPI_ALLREDUCE( omega_gen, omega_gen_old, nturbines, &
2452	! MPI_REAL,MPI_SUM, comm2d, ierr )
2453	#if defined( __parallel )
2454	CALL MPI_ALLREDUCE( torque_gen, torque_gen_old, nturbines, &
2455	MPI_REAL, MPI_SUM, comm2d, ierr )
2456	CALL MPI_ALLREDUCE( omega_rot_l, omega_rot, nturbines, &
2457	MPI_REAL, MPI_SUM, comm2d, ierr )
2458	CALL MPI_ALLREDUCE( omega_gen_f, omega_gen_f_old, nturbines, &
2459	MPI_REAL, MPI_SUM, comm2d, ierr )
2460	#else
2461	torque_gen_old = torque_gen
2462	omega_rot = omega_rot_l
2463	omega_gen_f_old = omega_gen_f
2464	#endif
2465
2466	ENDIF
2467
2468	DO inot = 1, nturbines
2469
2470	IF ( myid == 0 ) THEN
2471	IF ( openfile_turb_mod(400+inot)%opened ) THEN
2472	WRITE ( 400+inot, 106 ) simulated_time, omega_rot(inot), &
2473	omega_gen(inot), torque_gen_old(inot), &
2474	torque_total(inot), pitch_add(inot), &
2475	torque_gen_old(inot)omega_gen(inot)gen_eff, &
2476	torque_total(inot)omega_rot(inot)air_dens, &
2477	thrust_rotor(inot), &
2478	wdir(inot)*180.0_wp/pi, &
2479	(phi_yaw(inot))*180.0_wp/pi
2480
2481	ELSE
2482
2483	WRITE ( turbine_id,'(A2,I2.2)') '_T', inot
2484	OPEN ( 400+inot, FILE=( 'WTM_OUTPUT_DATA' // &
2485	TRIM( coupling_char ) // &
2486	turbine_id ), FORM='FORMATTED' )
2487	WRITE ( 400+inot, 105 ) inot
2488	WRITE ( 400+inot, 106 ) simulated_time, omega_rot(inot), &
2489	omega_gen(inot), torque_gen_old(inot), &
2490	torque_total(inot), pitch_add(inot), &
2491	torque_gen_old(inot)omega_gen(inot)gen_eff, &
2492	torque_total(inot)omega_rot(inot)air_dens, &
2493	thrust_rotor(inot), &
2494	wdir(inot)*180.0_wp/pi, &
2495	(phi_yaw(inot))*180.0_wp/pi
2496	ENDIF
2497	ENDIF
2498
2499	!-- Set open flag
2500	openfile_turb_mod(400+inot)%opened = .TRUE.
2501	ENDDO !-- end of loop over turbines
2502
2503	ENDIF
2504
2505	CALL cpu_log( log_point_s(61), 'wtm_forces', 'stop' )
2506
2507	!
2508	!-- Formats
2509	105 FORMAT ('Turbine control data for turbine ',I2,1X,':'/ &
2510	&'----------------------------------------'/ &
2511	&' Time RSpeed GSpeed ', &
2512	'GenTorque AeroTorque Pitch Power(Gen) Power(Rot) ', &
2513	'RotThrust WDirection YawOrient')
2514
2515	106 FORMAT (F9.3,2X,F7.3,2X,F7.2,2X,F9.1,3X,F9.1,1X,F6.2,2X,F10.1,2X, &
2516	F10.1,1X,F9.1,2X,F7.2,1X,F7.2)
2517
2518
2519	END SUBROUTINE wtm_forces
2520
2521
2522	!------------------------------------------------------------------------------!
2523	! Description:
2524	! ------------
2525	!> Yaw controller for the wind turbine model
2526	!------------------------------------------------------------------------------!
2527	SUBROUTINE wtm_yawcontrol( inot )
2528
2529	USE kinds
2530
2531	IMPLICIT NONE
2532
2533	INTEGER(iwp) :: inot
2534	INTEGER(iwp) :: i_wd_30
2535	REAL(wp) :: missal
2536
2537	i_wd_30 = 0_iwp
2538
2539	!
2540	!-- The yaw controller computes a 30s running mean of the wind direction.
2541	!-- If the difference between turbine alignment and wind direction exceeds
2542	!-- 5Â°, the turbine is yawed. The mechanism stops as soon as the 2s-running
2543	!-- mean of the missalignment is smaller than 0.5Â°.
2544	!-- Attention: If the timestep during the simulation changes significantly
2545	!-- the lengths of the running means change and it does not correspond to
2546	!-- 30s/2s anymore.
2547	!-- ! Needs to be modified for these situations !
2548	!-- For wind from the east, the averaging of the wind direction could cause
2549	!-- problems and the yaw controller is probably flawed. -> Routine for
2550	!-- averaging needs to be improved!
2551	!
2552	!-- Check if turbine is not yawing
2553	IF ( .NOT. doyaw(inot) ) THEN
2554	!
2555	!-- Write current wind direction into array
2556	wd30_l = wd30(inot,:)
2557	wd30_l = CSHIFT( wd30_l, SHIFT=-1 )
2558	wd30_l(1) = wdir(inot)
2559	!
2560	!-- Check if array is full ( no more dummies )
2561	IF ( .NOT. ANY( wd30_l == 999.) ) THEN
2562
2563	missal = SUM( wd30_l ) / SIZE( wd30_l ) - phi_yaw(inot)
2564	!
2565	!-- Check if turbine is missaligned by more than max_miss
2566	IF ( ABS( missal ) > max_miss ) THEN
2567	!
2568	!-- Check in which direction to yaw
2569	yawdir(inot) = SIGN( 1.0_wp, missal )
2570	!
2571	!-- Start yawing of turbine
2572	phi_yaw(inot) = phi_yaw(inot) + yawdir(inot) * yaw_speed * dt_3d
2573	doyaw(inot) = .TRUE.
2574	wd30_l = 999. ! fill with dummies again
2575	ENDIF
2576	ENDIF
2577
2578	wd30(inot,:) = wd30_l
2579
2580	!
2581	!-- If turbine is already yawing:
2582	!-- Initialize 2 s running mean and yaw until the missalignment is smaller
2583	!-- than min_miss
2584
2585	ELSE
2586	!
2587	!-- Initialize 2 s running mean
2588	wd2_l = wd2(inot,:)
2589	wd2_l = CSHIFT( wd2_l, SHIFT = -1 )
2590	wd2_l(1) = wdir(inot)
2591	!
2592	!-- Check if array is full ( no more dummies )
2593	IF ( .NOT. ANY( wd2_l == 999.0_wp ) ) THEN
2594	!
2595	!-- Calculate missalignment of turbine
2596	missal = SUM( wd2_l - phi_yaw(inot) ) / SIZE( wd2_l )
2597	!
2598	!-- Check if missalignment is still larger than 0.5 degree and if the
2599	!-- yaw direction is still right
2600	IF ( ( ABS( missal ) > min_miss ) .AND. &
2601	( yawdir(inot) == SIGN( 1.0_wp, missal ) ) ) THEN
2602	!
2603	!-- Continue yawing
2604	phi_yaw(inot) = phi_yaw(inot) + yawdir(inot) * yaw_speed * dt_3d
2605	ELSE
2606	!
2607	!-- Stop yawing
2608	doyaw(inot) = .FALSE.
2609	wd2_l = 999.0_wp ! fill with dummies again
2610	ENDIF
2611	ELSE
2612	!
2613	!-- Continue yawing
2614	phi_yaw(inot) = phi_yaw(inot) + yawdir(inot) * yaw_speed * dt_3d
2615	ENDIF
2616
2617	wd2(inot,:) = wd2_l
2618
2619	ENDIF
2620
2621	END SUBROUTINE wtm_yawcontrol
2622
2623
2624	!------------------------------------------------------------------------------!
2625	! Description:
2626	! ------------
2627	!> Initialization of the speed control
2628	!------------------------------------------------------------------------------!
2629	SUBROUTINE wtm_init_speed_control
2630
2631
2632	IMPLICIT NONE
2633
2634	!
2635	!-- If speed control is set, remaining variables and control_parameters for
2636	!-- the control algorithm are calculated
2637	!
2638	!-- Calculate slope constant for region 15
2639	slope15 = ( slope2 * min_reg2 * min_reg2 ) / ( min_reg2 - min_reg15 )
2640	!
2641	!-- Calculate upper limit of slipage region
2642	vs_sysp = rated_genspeed / 1.1_wp
2643	!
2644	!-- Calculate slope of slipage region
2645	slope25 = ( rated_power / rated_genspeed ) / &
2646	( rated_genspeed - vs_sysp )
2647	!
2648	!-- Calculate lower limit of slipage region
2649	min_reg25 = ( slope25 - SQRT( slope25 * ( slope25 - 4.0_wp * &
2650	slope2 * vs_sysp ) ) ) / &
2651	( 2.0_wp * slope2 )
2652	!
2653	!-- Frequency for the simple low pass filter
2654	Fcorner = 0.25_wp
2655	!
2656	!-- At the first timestep the torque is set to its maximum to prevent
2657	!-- an overspeeding of the rotor
2658	IF ( TRIM( initializing_actions ) /= 'read_restart_data' ) THEN
2659	torque_gen_old(:) = max_torque_gen
2660	ENDIF
2661
2662	END SUBROUTINE wtm_init_speed_control
2663
2664
2665	!------------------------------------------------------------------------------!
2666	! Description:
2667	! ------------
2668	!> Simple controller for the regulation of the rotor speed
2669	!------------------------------------------------------------------------------!
2670	SUBROUTINE wtm_speed_control( inot )
2671
2672
2673	IMPLICIT NONE
2674
2675	INTEGER(iwp) :: inot
2676
2677
2678
2679	!
2680	!-- The controller is based on the fortran script from Jonkman
2681	!-- et al. 2009 "Definition of a 5 MW Reference Wind Turbine for
2682	!-- offshore system developement"
2683
2684	!
2685	!-- The generator speed is filtered by a low pass filter
2686	!-- for the control of the generator torque
2687	lp_coeff = EXP( -2.0_wp * 3.14_wp * dt_3d * Fcorner )
2688	omega_gen_f(inot) = ( 1.0_wp - lp_coeff ) * omega_gen(inot) + lp_coeff *&
2689	omega_gen_f_old(inot)
2690
2691	IF ( omega_gen_f(inot) <= min_reg15 ) THEN
2692	!
2693	!-- Region 1: Generator torque is set to zero to accelerate the rotor:
2694	torque_gen(inot) = 0
2695
2696	ELSEIF ( omega_gen_f(inot) <= min_reg2 ) THEN
2697	!
2698	!-- Region 1.5: Generator torque is increasing linearly with rotor speed:
2699	torque_gen(inot) = slope15 * ( omega_gen_f(inot) - min_reg15 )
2700
2701	ELSEIF ( omega_gen_f(inot) <= min_reg25 ) THEN
2702	!
2703	!-- Region 2: Generator torque is increased by the square of the generator
2704	!-- speed to keep the TSR optimal:
2705	torque_gen(inot) = slope2 * omega_gen_f(inot) * omega_gen_f(inot)
2706
2707	ELSEIF ( omega_gen_f(inot) < rated_genspeed ) THEN
2708	!
2709	!-- Region 2.5: Slipage region between 2 and 3:
2710	torque_gen(inot) = slope25 * ( omega_gen_f(inot) - vs_sysp )
2711
2712	ELSE
2713	!
2714	!-- Region 3: Generator torque is antiproportional to the rotor speed to
2715	!-- keep the power constant:
2716	torque_gen(inot) = rated_power / omega_gen_f(inot)
2717
2718	ENDIF
2719	!
2720	!-- Calculate torque rate and confine with a max
2721	trq_rate = ( torque_gen(inot) - torque_gen_old(inot) ) / dt_3d
2722	trq_rate = MIN( MAX( trq_rate, -1.0_wp * max_trq_rate ), max_trq_rate )
2723	!
2724	!-- Calculate new gen torque and confine with max torque
2725	torque_gen(inot) = torque_gen_old(inot) + trq_rate * dt_3d
2726	torque_gen(inot) = MIN( torque_gen(inot), max_torque_gen )
2727	!
2728	!-- Overwrite values for next timestep
2729	omega_rot_l(inot) = omega_gen(inot) / gear_ratio
2730
2731
2732	END SUBROUTINE wtm_speed_control
2733
2734
2735	!------------------------------------------------------------------------------!
2736	! Description:
2737	! ------------
2738	!> Application of the additional forces generated by the wind turbine on the
2739	!> flow components (tendency terms)
2740	!> Call for all grid points
2741	!------------------------------------------------------------------------------!
2742	SUBROUTINE wtm_tendencies( component )
2743
2744
2745	IMPLICIT NONE
2746
2747	INTEGER(iwp) :: component !< prognostic variable (u,v,w)
2748	INTEGER(iwp) :: i !< running index
2749	INTEGER(iwp) :: j !< running index
2750	INTEGER(iwp) :: k !< running index
2751
2752
2753	SELECT CASE ( component )
2754
2755	CASE ( 1 )
2756	!
2757	!-- Apply the x-component of the force to the u-component of the flow:
2758	IF ( simulated_time >= time_turbine_on ) THEN
2759	DO i = nxlg, nxrg
2760	DO j = nysg, nyng
2761	DO k = nzb+1, MAXVAL(k_hub) + MAXVAL(k_smear)
2762	!
2763	!-- Calculate the thrust generated by the nacelle and the tower
2764	tend_nac_x = 0.5_wp * nac_cd_surf(k,j,i) * &
2765	SIGN( u(k,j,i)**2 , u(k,j,i) )
2766	tend_tow_x = 0.5_wp * tow_cd_surf(k,j,i) * &
2767	SIGN( u(k,j,i)**2 , u(k,j,i) )
2768
2769	tend(k,j,i) = tend(k,j,i) + ( - rot_tend_x(k,j,i) &
2770	- tend_nac_x - tend_tow_x ) &
2771	* MERGE( 1.0_wp, 0.0_wp, &
2772	BTEST( wall_flags_0(k,j,i), 1 ) )
2773	ENDDO
2774	ENDDO
2775	ENDDO
2776	ENDIF
2777
2778	CASE ( 2 )
2779	!
2780	!-- Apply the y-component of the force to the v-component of the flow:
2781	IF ( simulated_time >= time_turbine_on ) THEN
2782	DO i = nxlg, nxrg
2783	DO j = nysg, nyng
2784	DO k = nzb+1, MAXVAL(k_hub) + MAXVAL(k_smear)
2785	tend_nac_y = 0.5_wp * nac_cd_surf(k,j,i) * &
2786	SIGN( v(k,j,i)**2 , v(k,j,i) )
2787	tend_tow_y = 0.5_wp * tow_cd_surf(k,j,i) * &
2788	SIGN( v(k,j,i)**2 , v(k,j,i) )
2789	tend(k,j,i) = tend(k,j,i) + ( - rot_tend_y(k,j,i) &
2790	- tend_nac_y - tend_tow_y ) &
2791	* MERGE( 1.0_wp, 0.0_wp, &
2792	BTEST( wall_flags_0(k,j,i), 2 ) )
2793	ENDDO
2794	ENDDO
2795	ENDDO
2796	ENDIF
2797
2798	CASE ( 3 )
2799	!
2800	!-- Apply the z-component of the force to the w-component of the flow:
2801	IF ( simulated_time >= time_turbine_on ) THEN
2802	DO i = nxlg, nxrg
2803	DO j = nysg, nyng
2804	DO k = nzb+1, MAXVAL(k_hub) + MAXVAL(k_smear)
2805	tend(k,j,i) = tend(k,j,i) - rot_tend_z(k,j,i) &
2806	* MERGE( 1.0_wp, 0.0_wp, &
2807	BTEST( wall_flags_0(k,j,i), 3 ) )
2808	ENDDO
2809	ENDDO
2810	ENDDO
2811	ENDIF
2812
2813
2814	CASE DEFAULT
2815
2816	WRITE( message_string, * ) 'unknown prognostic variable: ', component
2817	CALL message( 'wtm_tendencies', 'PA04??', 1, 2, 0, 6, 0 )
2818
2819	END SELECT
2820
2821
2822	END SUBROUTINE wtm_tendencies
2823
2824
2825	!------------------------------------------------------------------------------!
2826	! Description:
2827	! ------------
2828	!> Application of the additional forces generated by the wind turbine on the
2829	!> flow components (tendency terms)
2830	!> Call for grid point i,j
2831	!------------------------------------------------------------------------------!
2832	SUBROUTINE wtm_tendencies_ij( i, j, component )
2833
2834
2835	IMPLICIT NONE
2836
2837	INTEGER(iwp) :: component !< prognostic variable (u,v,w)
2838	INTEGER(iwp) :: i !< running index
2839	INTEGER(iwp) :: j !< running index
2840	INTEGER(iwp) :: k !< running index
2841
2842	SELECT CASE ( component )
2843
2844	CASE ( 1 )
2845	!
2846	!-- Apply the x-component of the force to the u-component of the flow:
2847	IF ( simulated_time >= time_turbine_on ) THEN
2848	DO k = nzb+1, MAXVAL(k_hub) + MAXVAL(k_smear)
2849	!
2850	!-- Calculate the thrust generated by the nacelle and the tower
2851	tend_nac_x = 0.5_wp * nac_cd_surf(k,j,i) * &
2852	SIGN( u(k,j,i)**2 , u(k,j,i) )
2853	tend_tow_x = 0.5_wp * tow_cd_surf(k,j,i) * &
2854	SIGN( u(k,j,i)**2 , u(k,j,i) )
2855	tend(k,j,i) = tend(k,j,i) + ( - rot_tend_x(k,j,i) &
2856	- tend_nac_x - tend_tow_x ) &
2857	* MERGE( 1.0_wp, 0.0_wp, &
2858	BTEST( wall_flags_0(k,j,i), 1 ) )
2859	ENDDO
2860	ENDIF
2861
2862	CASE ( 2 )
2863	!
2864	!-- Apply the y-component of the force to the v-component of the flow:
2865	IF ( simulated_time >= time_turbine_on ) THEN
2866	DO k = nzb+1, MAXVAL(k_hub) + MAXVAL(k_smear)
2867	tend_nac_y = 0.5_wp * nac_cd_surf(k,j,i) * &
2868	SIGN( v(k,j,i)**2 , v(k,j,i) )
2869	tend_tow_y = 0.5_wp * tow_cd_surf(k,j,i) * &
2870	SIGN( v(k,j,i)**2 , v(k,j,i) )
2871	tend(k,j,i) = tend(k,j,i) + ( - rot_tend_y(k,j,i) &
2872	- tend_nac_y - tend_tow_y ) &
2873	* MERGE( 1.0_wp, 0.0_wp, &
2874	BTEST( wall_flags_0(k,j,i), 2 ) )
2875	ENDDO
2876	ENDIF
2877
2878	CASE ( 3 )
2879	!
2880	!-- Apply the z-component of the force to the w-component of the flow:
2881	IF ( simulated_time >= time_turbine_on ) THEN
2882	DO k = nzb+1, MAXVAL(k_hub) + MAXVAL(k_smear)
2883	tend(k,j,i) = tend(k,j,i) - rot_tend_z(k,j,i) &
2884	* MERGE( 1.0_wp, 0.0_wp, &
2885	BTEST( wall_flags_0(k,j,i), 3 ) )
2886	ENDDO
2887	ENDIF
2888
2889
2890	CASE DEFAULT
2891
2892	WRITE( message_string, * ) 'unknown prognostic variable: ', component
2893	CALL message( 'wtm_tendencies', 'PA04??', 1, 2, 0, 6, 0 )
2894
2895	END SELECT
2896
2897
2898	END SUBROUTINE wtm_tendencies_ij
2899
2900	END MODULE wind_turbine_model_mod

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