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source: palm/trunk/SOURCE/wind_turbine_model_mod.f90 @ 3082

Last change on this file since 3082 was 3069, checked in by witha, 6 years ago
Initialization of some arrays changed
Property svn:keywords set to `Id`
File size: 120.5 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 3069 2018-06-15 07:56:09Z gronemeier $
28	! Initialization of some arrays added
29	!
30	! 3066 2018-06-12 08:55:55Z Giersch
31	! Error message revised
32	!
33	! 3065 2018-06-12 07:03:02Z Giersch
34	! dz was replaced by dz(1), error message concerning grid stretching has been
35	! introduced
36	!
37	! 3049 2018-05-29 13:52:36Z Giersch
38	! Error messages revised
39	!
40	! 2932 2018-03-26 09:39:22Z Giersch
41	! renamed wind_turbine_par to wind_turbine_parameters
42	!
43	! 2894 2018-03-15 09:17:58Z Giersch
44	! variable named found has been introduced for checking if restart data was
45	! found, reading of restart strings has been moved completely to
46	! read_restart_data_mod, wind_turbine_prerun flag has been removed, redundant
47	! skipping function has been removed, wtm_read/write_restart_data have been
48	! renamed to wtm_r/wrd_global, wtm_rrd_global is called in
49	! read_restart_data_mod now, marker * end wtm * was removed, strings and
50	! their respective lengths are written out and read now in case of restart
51	! runs to get rid of prescribed character lengths, CASE DEFAULT was added if
52	! restart data is read
53	!
54	! 2885 2018-03-14 11:02:46Z Giersch
55	! Bugfix in interpolation of lift and drag coefficients on fine grid of radius
56	! segments and angles of attack, speed-up of the initialization of the wind
57	! turbine model
58	!
59	! 2792 2018-02-07 06:45:29Z Giersch
60	! omega_rot_l has to be calculated after determining the indices for the hub in
61	! case of restart runs
62	!
63	! 2776 2018-01-31 10:44:42Z Giersch
64	! wind_turbine_prerun flag is used to define if module
65	! related parameters were outputted as restart data
66	!
67	! 2718 2018-01-02 08:49:38Z maronga
68	! Corrected "Former revisions" section
69	!
70	! 2696 2017-12-14 17:12:51Z kanani
71	! Change in file header (GPL part)
72	!
73	! 2669 2017-12-06 16:03:27Z raasch
74	! filename of turbine output changed to WTM_OUTPUT_DATA. File extension now
75	! includes the nest domain number. Turbine extension changed to "_T##"
76	!
77	! 2576 2017-10-24 13:49:46Z Giersch
78	! Definition of a new function called wtm_skip_global to skip module
79	! parameters during reading restart data
80	!
81	! 2563 2017-10-19 15:36:10Z Giersch
82	! Restart runs with wind turbine model are possible now. For this purpose, two
83	! new subroutines wtm_write_restart_data and wtm_read_restart_data had to be
84	! defined
85	!
86	! 2553 2017-10-18 08:03:45Z Giersch
87	! Bugfix of vertical loop in wtm_tendencies to account for different turbine
88	! heights, bugfix of the interpolation of the u-component concerning the
89	! vertical index and further small adjustments of the programming style
90	!
91	! 2410 2017-09-06 08:16:30Z Giersch
92	! Revise error message PA0462
93	!
94	! 2349 2017-08-10 15:44:04Z Giersch
95	! Add parameter pitch_rate to namelist and revise/add error messages
96	!
97	! 2343 2017-08-08 11:28:43Z Giersch
98	! Unit correction in Doxygen comments
99	!
100	! 2323 2017-07-26 12:57:38Z Giersch
101	! Change unit number of file WTM_DATA from 201 to 90
102	!
103	! 2322 2017-07-26 08:30:28Z Giersch
104	! Bugfix of error message and assign error numbers
105	!
106	! 2257 2017-06-07 14:07:05Z witha
107	! Bugfix: turb_cl_tab and turb_cd_tab were set to zero before being allocated
108	!
109	! 2233 2017-05-30 18:08:54Z suehring
110	!
111	! 2232 2017-05-30 17:47:52Z suehring
112	! Adjustments to new topography concept
113	!
114	! 2152 2017-02-17 13:27:24Z lvollmer
115	! Bugfix in subroutine wtm_read_blade_tables
116	! Addition of a tip loss model
117	!
118	! 2015 2016-09-28 08:45:18Z lvollmer
119	! Bugfix of pitch control
120	!
121	! 2000 2016-08-20 18:09:15Z knoop
122	! Forced header and separation lines into 80 columns
123	!
124	! 1929 2016-06-09 16:25:25Z suehring
125	! Bugfix: added preprocessor directives for parallel and serial mode
126	!
127	! 1914 2016-05-26 14:44:07Z witha
128	! Initial revision
129	!
130	!
131	! Description:
132	! ------------
133	!> This module calculates the effect of wind turbines on the flow fields. The
134	!> initial version contains only the advanced actuator disk with rotation method
135	!> (ADM-R).
136	!> The wind turbines include the tower effect, can be yawed and tilted.
137	!> The wind turbine model includes controllers for rotational speed, pitch and
138	!> yaw.
139	!> Currently some specifications of the NREL 5 MW reference turbine
140	!> are hardcoded whereas most input data comes from separate files (currently
141	!> external, planned to be included as namelist which will be read in
142	!> automatically).
143	!>
144	!> @todo Replace dz(1) appropriatly to account for grid stretching
145	!> @todo Revise code according to PALM Coding Standard
146	!> @todo Implement ADM and ALM turbine models
147	!> @todo Generate header information
148	!> @todo Implement further parameter checks and error messages
149	!> @todo Revise and add code documentation
150	!> @todo Output turbine parameters as timeseries
151	!> @todo Include additional output variables
152	!> @todo Revise smearing the forces for turbines in yaw
153	!> @todo Revise nacelle and tower parameterization
154	!> @todo Allow different turbine types in one simulation
155	!
156	!------------------------------------------------------------------------------!
157	MODULE wind_turbine_model_mod
158
159	USE arrays_3d, &
160	ONLY: tend, u, v, w, zu, zw
161
162	USE constants, &
163	ONLY: pi
164
165	USE control_parameters, &
166	ONLY: coupling_char, dt_3d, dz, message_string, simulated_time, &
167	wind_turbine, initializing_actions
168
169	USE cpulog, &
170	ONLY: cpu_log, log_point_s
171
172	USE grid_variables, &
173	ONLY: ddx, dx, ddy, dy
174
175	USE indices, &
176	ONLY: nbgp, nx, nxl, nxlg, nxr, nxrg, ny, nyn, nyng, nys, nysg, nz, &
177	nzb, nzt, wall_flags_0
178
179	USE kinds
180
181	USE pegrid
182
183
184	IMPLICIT NONE
185
186	PRIVATE
187
188	!
189	!-- Variables specified in the namelist wind_turbine_par
190
191	INTEGER(iwp) :: nairfoils = 8 !< number of airfoils of the used turbine model (for ADM-R and ALM)
192	INTEGER(iwp) :: nturbines = 1 !< number of turbines
193
194	LOGICAL :: pitch_control = .FALSE. !< switch for use of pitch controller
195	LOGICAL :: speed_control = .FALSE. !< switch for use of speed controller
196	LOGICAL :: yaw_control = .FALSE. !< switch for use of yaw controller
197	LOGICAL :: tl_cor = .FALSE. !< switch for use of tip loss correct.
198
199	REAL(wp) :: segment_length = 1.0_wp !< length of the segments, the rotor area is divided into
200	!< (in tangential direction, as factor of MIN(dx,dy,dz))
201	REAL(wp) :: segment_width = 0.5_wp !< width of the segments, the rotor area is divided into
202	!< (in radial direction, as factor of MIN(dx,dy,dz))
203	REAL(wp) :: time_turbine_on = 0.0_wp !< time at which turbines are started
204	REAL(wp) :: tilt = 0.0_wp !< vertical tilt of the rotor [degree] ( positive = backwards )
205
206	REAL(wp), DIMENSION(1:100) :: dtow = 0.0_wp !< tower diameter [m]
207	REAL(wp), DIMENSION(1:100) :: omega_rot = 0.9_wp !< inital or constant rotor speed [rad/s]
208	REAL(wp), DIMENSION(1:100) :: phi_yaw = 0.0_wp !< yaw angle [degree] ( clockwise, 0 = facing west )
209	REAL(wp), DIMENSION(1:100) :: pitch_add = 0.0_wp !< constant pitch angle
210	REAL(wp), DIMENSION(1:100) :: rcx = 9999999.9_wp !< position of hub in x-direction
211	REAL(wp), DIMENSION(1:100) :: rcy = 9999999.9_wp !< position of hub in y-direction
212	REAL(wp), DIMENSION(1:100) :: rcz = 9999999.9_wp !< position of hub in z-direction
213	REAL(wp), DIMENSION(1:100) :: rnac = 0.0_wp !< nacelle diameter [m]
214	REAL(wp), DIMENSION(1:100) :: rr = 63.0_wp !< rotor radius [m]
215	REAL(wp), DIMENSION(1:100) :: turb_cd_nacelle = 0.85_wp !< drag coefficient for nacelle
216	REAL(wp), DIMENSION(1:100) :: turb_cd_tower = 1.2_wp !< drag coefficient for tower
217
218	!
219	!-- Variables specified in the namelist for speed controller
220	!-- Default values are from the NREL 5MW research turbine (Jonkman, 2008)
221
222	REAL(wp) :: rated_power = 5296610.0_wp !< rated turbine power [W]
223	REAL(wp) :: gear_ratio = 97.0_wp !< Gear ratio from rotor to generator
224	REAL(wp) :: inertia_rot = 34784179.0_wp !< Inertia of the rotor [kg*m2]
225	REAL(wp) :: inertia_gen = 534.116_wp !< Inertia of the generator [kg*m2]
226	REAL(wp) :: gen_eff = 0.944_wp !< Electric efficiency of the generator
227	REAL(wp) :: gear_eff = 1.0_wp !< Loss between rotor and generator
228	REAL(wp) :: air_dens = 1.225_wp !< Air density to convert to W [kg/m3]
229	REAL(wp) :: rated_genspeed = 121.6805_wp !< Rated generator speed [rad/s]
230	REAL(wp) :: max_torque_gen = 47402.91_wp !< Maximum of the generator torque [Nm]
231	REAL(wp) :: slope2 = 2.332287_wp !< Slope constant for region 2
232	REAL(wp) :: min_reg2 = 91.21091_wp !< Lower generator speed boundary of region 2 [rad/s]
233	REAL(wp) :: min_reg15 = 70.16224_wp !< Lower generator speed boundary of region 1.5 [rad/s]
234	REAL(wp) :: max_trq_rate = 15000.0_wp !< Max generator torque increase [Nm/s]
235	REAL(wp) :: pitch_rate = 8.0_wp !< Max pitch rate [degree/s]
236
237
238	!
239	!-- Variables specified in the namelist for yaw control
240
241	REAL(wp) :: yaw_speed = 0.005236_wp !< speed of the yaw actuator [rad/s]
242	REAL(wp) :: max_miss = 0.08726_wp !< maximum tolerated yaw missalignment [rad]
243	REAL(wp) :: min_miss = 0.008726_wp !< minimum yaw missalignment for which the actuator stops [rad]
244
245	!
246	!-- Set flag for output files TURBINE_PARAMETERS
247	TYPE file_status
248	LOGICAL :: opened, opened_before
249	END TYPE file_status
250
251	TYPE(file_status), DIMENSION(500) :: openfile_turb_mod = &
252	file_status(.FALSE.,.FALSE.)
253
254	!
255	!-- Variables for initialization of the turbine model
256
257	INTEGER(iwp) :: inot !< turbine loop index (turbine id)
258	INTEGER(iwp) :: nsegs_max !< maximum number of segments (all turbines, required for allocation of arrays)
259	INTEGER(iwp) :: nrings_max !< maximum number of rings (all turbines, required for allocation of arrays)
260	INTEGER(iwp) :: ring !< ring loop index (ring number)
261	INTEGER(iwp) :: rr_int !<
262	INTEGER(iwp) :: upper_end !<
263
264	INTEGER(iwp), DIMENSION(1) :: lct !<
265
266	INTEGER(iwp), DIMENSION(:), ALLOCATABLE :: i_hub !< index belonging to x-position of the turbine
267	INTEGER(iwp), DIMENSION(:), ALLOCATABLE :: i_smear !< index defining the area for the smearing of the forces (x-direction)
268	INTEGER(iwp), DIMENSION(:), ALLOCATABLE :: j_hub !< index belonging to y-position of the turbine
269	INTEGER(iwp), DIMENSION(:), ALLOCATABLE :: j_smear !< index defining the area for the smearing of the forces (y-direction)
270	INTEGER(iwp), DIMENSION(:), ALLOCATABLE :: k_hub !< index belonging to hub height
271	INTEGER(iwp), DIMENSION(:), ALLOCATABLE :: k_smear !< index defining the area for the smearing of the forces (z-direction)
272	INTEGER(iwp), DIMENSION(:), ALLOCATABLE :: nrings !< number of rings per turbine
273	INTEGER(iwp), DIMENSION(:), ALLOCATABLE :: nsegs_total !< total number of segments per turbine
274
275	INTEGER(iwp), DIMENSION(:,:), ALLOCATABLE :: nsegs !< number of segments per ring and turbine
276
277	!
278	!- parameters for the smearing from the rotor to the cartesian grid
279	REAL(wp) :: pol_a !< parameter for the polynomial smearing fct
280	REAL(wp) :: pol_b !< parameter for the polynomial smearing fct
281	REAL(wp) :: delta_t_factor !<
282	REAL(wp) :: eps_factor !<
283	REAL(wp) :: eps_min !<
284	REAL(wp) :: eps_min2 !<
285	REAL(wp) :: sqrt_arg !<
286
287	!
288	!-- Variables for the calculation of lift and drag coefficients
289	REAL(wp), DIMENSION(:), ALLOCATABLE :: ard !<
290	REAL(wp), DIMENSION(:), ALLOCATABLE :: crd !<
291	REAL(wp), DIMENSION(:), ALLOCATABLE :: delta_r !< radial segment length
292	REAL(wp), DIMENSION(:), ALLOCATABLE :: lrd !<
293
294	REAL(wp) :: accu_cl_cd_tab = 0.1_wp !< Accuracy of the interpolation of
295	!< the lift and drag coeff [deg]
296
297	REAL(wp), DIMENSION(:,:), ALLOCATABLE :: turb_cd_tab !< table of the blade drag coefficient
298	REAL(wp), DIMENSION(:,:), ALLOCATABLE :: turb_cl_tab !< table of the blade lift coefficient
299
300	REAL(wp), DIMENSION(:,:,:), ALLOCATABLE :: nac_cd_surf !< 3d field of the tower drag coefficient
301	REAL(wp), DIMENSION(:,:,:), ALLOCATABLE :: tow_cd_surf !< 3d field of the nacelle drag coefficient
302
303	!
304	!-- Variables for the calculation of the forces
305
306	REAL(wp) :: cur_r !<
307	REAL(wp) :: phi_rotor !<
308	REAL(wp) :: pre_factor !<
309	REAL(wp) :: torque_seg !<
310	REAL(wp) :: u_int_l !<
311	REAL(wp) :: u_int_u !<
312	REAL(wp) :: u_rot !<
313	REAL(wp) :: v_int_l !<
314	REAL(wp) :: v_int_u !<
315	REAL(wp) :: w_int_l !<
316	REAL(wp) :: w_int_u !<
317	!
318	!- Tendencies from the nacelle and tower thrust
319	REAL(wp) :: tend_nac_x = 0.0_wp !<
320	REAL(wp) :: tend_tow_x = 0.0_wp !<
321	REAL(wp) :: tend_nac_y = 0.0_wp !<
322	REAL(wp) :: tend_tow_y = 0.0_wp !<
323
324	REAL(wp), DIMENSION(:), ALLOCATABLE :: alpha_attack !<
325	REAL(wp), DIMENSION(:), ALLOCATABLE :: chord !<
326	REAL(wp), DIMENSION(:), ALLOCATABLE :: phi_rel !<
327	REAL(wp), DIMENSION(:), ALLOCATABLE :: torque_total !<
328	REAL(wp), DIMENSION(:), ALLOCATABLE :: thrust_rotor !<
329	REAL(wp), DIMENSION(:), ALLOCATABLE :: turb_cl !<
330	REAL(wp), DIMENSION(:), ALLOCATABLE :: turb_cd !<
331	REAL(wp), DIMENSION(:), ALLOCATABLE :: vrel !<
332	REAL(wp), DIMENSION(:), ALLOCATABLE :: vtheta !<
333
334	REAL(wp), DIMENSION(:,:), ALLOCATABLE :: rbx, rby, rbz !< coordinates of the blade elements
335	REAL(wp), DIMENSION(:,:), ALLOCATABLE :: rotx, roty, rotz !< normal vectors to the rotor coordinates
336
337	!
338	!- Fields for the interpolation of velocities on the rotor grid
339	REAL(wp), DIMENSION(:,:,:), ALLOCATABLE :: u_int !<
340	REAL(wp), DIMENSION(:,:,:), ALLOCATABLE :: u_int_1_l !<
341	REAL(wp), DIMENSION(:,:,:), ALLOCATABLE :: v_int !<
342	REAL(wp), DIMENSION(:,:,:), ALLOCATABLE :: v_int_1_l !<
343	REAL(wp), DIMENSION(:,:,:), ALLOCATABLE :: w_int !<
344	REAL(wp), DIMENSION(:,:,:), ALLOCATABLE :: w_int_1_l !<
345
346	!
347	!- rotor tendencies on the segments
348	REAL(wp), DIMENSION(:), ALLOCATABLE :: thrust_seg !<
349	REAL(wp), DIMENSION(:), ALLOCATABLE :: torque_seg_y !<
350	REAL(wp), DIMENSION(:), ALLOCATABLE :: torque_seg_z !<
351
352	!
353	!- rotor tendencies on the rings
354	REAL(wp), DIMENSION(:,:), ALLOCATABLE :: thrust_ring !<
355	REAL(wp), DIMENSION(:,:), ALLOCATABLE :: torque_ring_y !<
356	REAL(wp), DIMENSION(:,:), ALLOCATABLE :: torque_ring_z !<
357
358	!
359	!- rotor tendencies on rotor grids for all turbines
360	REAL(wp), DIMENSION(:,:,:), ALLOCATABLE :: thrust !<
361	REAL(wp), DIMENSION(:,:,:), ALLOCATABLE :: torque_y !<
362	REAL(wp), DIMENSION(:,:,:), ALLOCATABLE :: torque_z !<
363
364	!
365	!- rotor tendencies on coordinate grid
366	REAL(wp), DIMENSION(:,:,:), ALLOCATABLE :: rot_tend_x !<
367	REAL(wp), DIMENSION(:,:,:), ALLOCATABLE :: rot_tend_y !<
368	REAL(wp), DIMENSION(:,:,:), ALLOCATABLE :: rot_tend_z !<
369	!
370	!- variables for the rotation of the rotor coordinates
371	REAL(wp), DIMENSION(1:100,1:3,1:3) :: rot_coord_trans !< matrix for rotation of rotor coordinates
372
373	REAL(wp), DIMENSION(1:3) :: rot_eigen_rad !<
374	REAL(wp), DIMENSION(1:3) :: rot_eigen_azi !<
375	REAL(wp), DIMENSION(1:3) :: rot_eigen_nor !<
376	REAL(wp), DIMENSION(1:3) :: re !<
377	REAL(wp), DIMENSION(1:3) :: rea !<
378	REAL(wp), DIMENSION(1:3) :: ren !<
379	REAL(wp), DIMENSION(1:3) :: rote !<
380	REAL(wp), DIMENSION(1:3) :: rota !<
381	REAL(wp), DIMENSION(1:3) :: rotn !<
382
383	!
384	!-- Fixed variables for the speed controller
385
386	LOGICAL :: start_up = .TRUE. !<
387
388	REAL(wp) :: Fcorner !< corner freq for the controller low pass filter
389	REAL(wp) :: min_reg25 !< min region 2.5
390	REAL(wp) :: om_rate !< rotor speed change
391	REAL(wp) :: slope15 !< slope in region 1.5
392	REAL(wp) :: slope25 !< slope in region 2.5
393	REAL(wp) :: trq_rate !< torque change
394	REAL(wp) :: vs_sysp !<
395	REAL(wp) :: lp_coeff !< coeff for the controller low pass filter
396
397	REAL(wp), DIMENSION(100) :: omega_rot_l = 0.0_wp !< local rot speed [rad/s]
398
399	!
400	!-- Fixed variables for the yaw controller
401
402	REAL(wp), DIMENSION(:) , ALLOCATABLE :: yawdir !< direction to yaw
403	REAL(wp), DIMENSION(:) , ALLOCATABLE :: phi_yaw_l !< local (cpu) yaw angle
404	REAL(wp), DIMENSION(:) , ALLOCATABLE :: wd30_l !< local (cpu) long running avg of the wd
405	REAL(wp), DIMENSION(:) , ALLOCATABLE :: wd2_l !< local (cpu) short running avg of the wd
406	REAL(wp), DIMENSION(:) , ALLOCATABLE :: wdir !< wind direction at hub
407	REAL(wp), DIMENSION(:) , ALLOCATABLE :: u_inflow !< wind speed at hub
408	REAL(wp), DIMENSION(:) , ALLOCATABLE :: wdir_l !<
409	REAL(wp), DIMENSION(:) , ALLOCATABLE :: u_inflow_l !<
410	REAL(wp), DIMENSION(:,:), ALLOCATABLE :: wd30 !<
411	REAL(wp), DIMENSION(:,:), ALLOCATABLE :: wd2 !<
412	LOGICAL, DIMENSION(1:100) :: doyaw = .FALSE. !<
413	INTEGER(iwp) :: WDLON !<
414	INTEGER(iwp) :: WDSHO !<
415
416	!
417	!-- Variables that have to be saved in the binary file for restarts
418	REAL(wp), DIMENSION(1:100) :: pitch_add_old = 0.0_wp !< old constant pitch angle
419	REAL(wp), DIMENSION(1:100) :: omega_gen = 0.0_wp !< curr. generator speed
420	REAL(wp), DIMENSION(1:100) :: omega_gen_f = 0.0_wp !< filtered generator speed
421	REAL(wp), DIMENSION(1:100) :: omega_gen_old = 0.0_wp !< last generator speed
422	REAL(wp), DIMENSION(1:100) :: omega_gen_f_old = 0.0_wp !< last filtered generator speed
423	REAL(wp), DIMENSION(1:100) :: torque_gen = 0.0_wp !< generator torque
424	REAL(wp), DIMENSION(1:100) :: torque_gen_old = 0.0_wp !< last generator torque
425
426
427	SAVE
428
429
430	INTERFACE wtm_parin
431	MODULE PROCEDURE wtm_parin
432	END INTERFACE wtm_parin
433
434	INTERFACE wtm_wrd_global
435	MODULE PROCEDURE wtm_wrd_global
436	END INTERFACE wtm_wrd_global
437
438	INTERFACE wtm_rrd_global
439	MODULE PROCEDURE wtm_rrd_global
440	END INTERFACE wtm_rrd_global
441
442	INTERFACE wtm_check_parameters
443	MODULE PROCEDURE wtm_check_parameters
444	END INTERFACE wtm_check_parameters
445
446	INTERFACE wtm_init_arrays
447	MODULE PROCEDURE wtm_init_arrays
448	END INTERFACE wtm_init_arrays
449
450	INTERFACE wtm_init
451	MODULE PROCEDURE wtm_init
452	END INTERFACE wtm_init
453
454	INTERFACE wtm_read_blade_tables
455	MODULE PROCEDURE wtm_read_blade_tables
456	END INTERFACE wtm_read_blade_tables
457
458	INTERFACE wtm_forces
459	MODULE PROCEDURE wtm_forces
460	END INTERFACE wtm_forces
461
462	INTERFACE wtm_yawcontrol
463	MODULE PROCEDURE wtm_yawcontrol
464	END INTERFACE wtm_yawcontrol
465
466	INTERFACE wtm_rotate_rotor
467	MODULE PROCEDURE wtm_rotate_rotor
468	END INTERFACE wtm_rotate_rotor
469
470	INTERFACE wtm_speed_control
471	MODULE PROCEDURE wtm_init_speed_control
472	MODULE PROCEDURE wtm_speed_control
473	END INTERFACE wtm_speed_control
474
475	INTERFACE wtm_tendencies
476	MODULE PROCEDURE wtm_tendencies
477	MODULE PROCEDURE wtm_tendencies_ij
478	END INTERFACE wtm_tendencies
479
480
481	PUBLIC wtm_check_parameters, wtm_forces, wtm_init, wtm_init_arrays, &
482	wtm_parin, wtm_wrd_global, wtm_rrd_global, wtm_tendencies
483
484
485	CONTAINS
486
487
488	!------------------------------------------------------------------------------!
489	! Description:
490	! ------------
491	!> Parin for &wind_turbine_par for wind turbine model
492	!------------------------------------------------------------------------------!
493	SUBROUTINE wtm_parin
494
495
496	IMPLICIT NONE
497
498	INTEGER(iwp) :: ierrn !<
499
500	CHARACTER (LEN=80) :: line !< dummy string that contains the current line of the parameter file
501
502	NAMELIST /wind_turbine_par/ air_dens, dtow, gear_eff, gear_ratio, &
503	gen_eff, inertia_gen, inertia_rot, max_miss, &
504	max_torque_gen, max_trq_rate, min_miss, &
505	min_reg15, min_reg2, nairfoils, nturbines, &
506	omega_rot, phi_yaw, pitch_add, pitch_control,&
507	rated_genspeed, rated_power, rcx, rcy, rcz, &
508	rnac, rr, segment_length, segment_width, &
509	slope2, speed_control, tilt, time_turbine_on,&
510	turb_cd_nacelle, turb_cd_tower, pitch_rate, &
511	yaw_control, yaw_speed, tl_cor
512
513	NAMELIST /wind_turbine_parameters/ &
514	air_dens, dtow, gear_eff, gear_ratio, &
515	gen_eff, inertia_gen, inertia_rot, max_miss, &
516	max_torque_gen, max_trq_rate, min_miss, &
517	min_reg15, min_reg2, nairfoils, nturbines, &
518	omega_rot, phi_yaw, pitch_add, pitch_control,&
519	rated_genspeed, rated_power, rcx, rcy, rcz, &
520	rnac, rr, segment_length, segment_width, &
521	slope2, speed_control, tilt, time_turbine_on,&
522	turb_cd_nacelle, turb_cd_tower, pitch_rate, &
523	yaw_control, yaw_speed, tl_cor
524	!
525	!-- Try to find wind turbine model package
526	REWIND ( 11 )
527	line = ' '
528	DO WHILE ( INDEX( line, '&wind_turbine_parameters' ) == 0 )
529	READ ( 11, '(A)', END=10 ) line
530	ENDDO
531	BACKSPACE ( 11 )
532
533	!
534	!-- Read user-defined namelist
535	READ ( 11, wind_turbine_parameters, IOSTAT=ierrn )
536
537	IF ( ierrn < 0 ) THEN
538	message_string = 'no wind_turbine_parameters-NAMELIST found: ' // &
539	'End of file has reached'
540	CALL message( 'wtm_parin', 'PA0460', 1, 2, 0, 6, 0 )
541	ELSEIF ( ierrn > 0 ) THEN
542	message_string = 'errors in wind_turbine_parameters-NAMELIST: ' // &
543	'some variables for steering may not be properly set'
544	CALL message( 'wtm_parin', 'PA0466', 1, 2, 0, 6, 0 )
545	ENDIF
546
547	!
548	!-- Set flag that indicates that the wind turbine model is switched on
549	wind_turbine = .TRUE.
550
551	GOTO 12
552
553	!
554	!-- Try to find wind turbine model package
555	10 REWIND ( 11 )
556	line = ' '
557	DO WHILE ( INDEX( line, '&wind_turbine_par' ) == 0 )
558	READ ( 11, '(A)', END=12 ) line
559	ENDDO
560	BACKSPACE ( 11 )
561
562	!
563	!-- Read user-defined namelist
564	READ ( 11, wind_turbine_par, IOSTAT=ierrn )
565
566	IF ( ierrn < 0 ) THEN
567	message_string = 'no wind_turbine_par-NAMELIST found: ' // &
568	'End of file has reached'
569	CALL message( 'wtm_parin', 'PA0460', 1, 2, 0, 6, 0 )
570	ELSEIF ( ierrn > 0 ) THEN
571	message_string = 'errors in wind_turbine_par-NAMELIST: ' // &
572	'some variables for steering may not be properly set'
573	CALL message( 'wtm_parin', 'PA0466', 1, 2, 0, 6, 0 )
574	ENDIF
575
576	message_string = 'namelist wind_tubrine_par is deprecated and will ' // &
577	'be removed in near future. &Please use namelist ' // &
578	'wind_turbine_parameters instead'
579	CALL message( 'wtm_parin', 'PA0487', 0, 1, 0, 6, 0 )
580
581	!
582	!-- Set flag that indicates that the wind turbine model is switched on
583	wind_turbine = .TRUE.
584
585	12 CONTINUE ! TBD Change from continue, mit ierrn machen
586
587
588	END SUBROUTINE wtm_parin
589
590
591	!------------------------------------------------------------------------------!
592	! Description:
593	! ------------
594	!> This routine writes the respective restart data.
595	!------------------------------------------------------------------------------!
596	SUBROUTINE wtm_wrd_global
597
598
599	IMPLICIT NONE
600
601
602	CALL wrd_write_string( 'omega_gen' )
603	WRITE ( 14 ) omega_gen
604
605	CALL wrd_write_string( 'omega_gen_f' )
606	WRITE ( 14 ) omega_gen_f
607
608	CALL wrd_write_string( 'omega_gen_f_old' )
609	WRITE ( 14 ) omega_gen_f_old
610
611	CALL wrd_write_string( 'omega_gen_old' )
612	WRITE ( 14 ) omega_gen_old
613
614	CALL wrd_write_string( 'omega_rot' )
615	WRITE ( 14 ) omega_rot
616
617	CALL wrd_write_string( 'phi_yaw' )
618	WRITE ( 14 ) phi_yaw
619
620	CALL wrd_write_string( 'pitch_add' )
621	WRITE ( 14 ) pitch_add
622
623	CALL wrd_write_string( 'pitch_add_old' )
624	WRITE ( 14 ) pitch_add_old
625
626	CALL wrd_write_string( 'torque_gen' )
627	WRITE ( 14 ) torque_gen
628
629	CALL wrd_write_string( 'torque_gen_old' )
630	WRITE ( 14 ) torque_gen_old
631
632
633	END SUBROUTINE wtm_wrd_global
634
635
636	!------------------------------------------------------------------------------!
637	! Description:
638	! ------------
639	!> This routine reads the respective restart data.
640	!------------------------------------------------------------------------------!
641	SUBROUTINE wtm_rrd_global( found )
642
643
644	USE control_parameters, &
645	ONLY: length, restart_string
646
647
648	IMPLICIT NONE
649
650	LOGICAL, INTENT(OUT) :: found
651
652
653	found = .TRUE.
654
655
656	SELECT CASE ( restart_string(1:length) )
657
658	CASE ( 'omega_gen' )
659	READ ( 13 ) omega_gen
660	CASE ( 'omega_gen_f' )
661	READ ( 13 ) omega_gen_f
662	CASE ( 'omega_gen_f_old' )
663	READ ( 13 ) omega_gen_f_old
664	CASE ( 'omega_gen_old' )
665	READ ( 13 ) omega_gen_old
666	CASE ( 'omega_rot' )
667	READ ( 13 ) omega_rot
668	CASE ( 'phi_yaw' )
669	READ ( 13 ) phi_yaw
670	CASE ( 'pitch_add' )
671	READ ( 13 ) pitch_add
672	CASE ( 'pitch_add_old' )
673	READ ( 13 ) pitch_add_old
674	CASE ( 'torque_gen' )
675	READ ( 13 ) torque_gen
676	CASE ( 'torque_gen_old' )
677	READ ( 13 ) torque_gen_old
678
679	CASE DEFAULT
680
681	found = .FALSE.
682
683	END SELECT
684
685
686	END SUBROUTINE wtm_rrd_global
687
688
689	!------------------------------------------------------------------------------!
690	! Description:
691	! ------------
692	!> Check namelist parameter
693	!------------------------------------------------------------------------------!
694	SUBROUTINE wtm_check_parameters
695
696
697	IMPLICIT NONE
698
699	IF ( ( .NOT.speed_control ) .AND. pitch_control ) THEN
700	message_string = 'pitch_control = .TRUE. requires '// &
701	'speed_control = .TRUE.'
702	CALL message( 'wtm_check_parameters', 'PA0461', 1, 2, 0, 6, 0 )
703	ENDIF
704
705	IF ( ANY( omega_rot(1:nturbines) < 0.0 ) ) THEN
706	message_string = 'omega_rot < 0.0, Please set omega_rot to ' // &
707	'a value equal or larger than zero'
708	CALL message( 'wtm_check_parameters', 'PA0462', 1, 2, 0, 6, 0 )
709	ENDIF
710
711
712	IF ( ANY( rcx(1:nturbines) == 9999999.9_wp ) .OR. &
713	ANY( rcy(1:nturbines) == 9999999.9_wp ) .OR. &
714	ANY( rcz(1:nturbines) == 9999999.9_wp ) ) THEN
715
716	message_string = 'rcx, rcy, rcz ' // &
717	'have to be given for each turbine.'
718	CALL message( 'wtm_check_parameters', 'PA0463', 1, 2, 0, 6, 0 )
719
720	ENDIF
721
722
723	END SUBROUTINE wtm_check_parameters
724
725
726	!------------------------------------------------------------------------------!
727	! Description:
728	! ------------
729	!> Allocate wind turbine model arrays
730	!------------------------------------------------------------------------------!
731	SUBROUTINE wtm_init_arrays
732
733
734	IMPLICIT NONE
735
736	REAL(wp) :: delta_r_factor !<
737	REAL(wp) :: delta_r_init !<
738
739	!
740	!-- To be able to allocate arrays with dimension of rotor rings and segments,
741	!-- the maximum possible numbers of rings and segments have to be calculated:
742
743	ALLOCATE( nrings(1:nturbines) )
744	ALLOCATE( delta_r(1:nturbines) )
745
746	nrings(:) = 0
747	delta_r(:) = 0.0_wp
748
749	!
750	!-- Thickness (radial) of each ring and length (tangential) of each segment:
751	delta_r_factor = segment_width
752	delta_t_factor = segment_length
753	delta_r_init = delta_r_factor * MIN( dx, dy, dz(1))
754
755	DO inot = 1, nturbines
756	!
757	!-- Determine number of rings:
758	nrings(inot) = NINT( rr(inot) / delta_r_init )
759
760	delta_r(inot) = rr(inot) / nrings(inot)
761
762	ENDDO
763
764	nrings_max = MAXVAL(nrings)
765
766	ALLOCATE( nsegs(1:nrings_max,1:nturbines) )
767	ALLOCATE( nsegs_total(1:nturbines) )
768
769	nsegs(:,:) = 0
770	nsegs_total(:) = 0
771
772
773	DO inot = 1, nturbines
774	DO ring = 1, nrings(inot)
775	!
776	!-- Determine number of segments for each ring:
777	nsegs(ring,inot) = MAX( 8, CEILING( delta_r_factor * pi * &
778	( 2.0_wp * ring - 1.0_wp ) / &
779	delta_t_factor ) )
780	ENDDO
781	!
782	!-- Total sum of all rotor segments:
783	nsegs_total(inot) = SUM( nsegs(:,inot) )
784
785	ENDDO
786
787	!
788	!-- Maximum number of segments per ring:
789	nsegs_max = MAXVAL(nsegs)
790
791	!!
792	!!-- TODO: Folgendes im Header ausgeben!
793	! IF ( myid == 0 ) THEN
794	! PRINT*, 'nrings(1) = ', nrings(1)
795	! PRINT*, '--------------------------------------------------'
796	! PRINT*, 'nsegs(:,1) = ', nsegs(:,1)
797	! PRINT*, '--------------------------------------------------'
798	! PRINT*, 'nrings_max = ', nrings_max
799	! PRINT*, 'nsegs_max = ', nsegs_max
800	! PRINT*, 'nsegs_total(1) = ', nsegs_total(1)
801	! ENDIF
802
803
804	!
805	!-- Allocate 1D arrays (dimension = number of turbines)
806	ALLOCATE( i_hub(1:nturbines) )
807	ALLOCATE( i_smear(1:nturbines) )
808	ALLOCATE( j_hub(1:nturbines) )
809	ALLOCATE( j_smear(1:nturbines) )
810	ALLOCATE( k_hub(1:nturbines) )
811	ALLOCATE( k_smear(1:nturbines) )
812	ALLOCATE( torque_total(1:nturbines) )
813	ALLOCATE( thrust_rotor(1:nturbines) )
814
815	!
816	!-- Allocation of the 1D arrays for yaw control
817	ALLOCATE( yawdir(1:nturbines) )
818	ALLOCATE( u_inflow(1:nturbines) )
819	ALLOCATE( wdir(1:nturbines) )
820	ALLOCATE( u_inflow_l(1:nturbines) )
821	ALLOCATE( wdir_l(1:nturbines) )
822	ALLOCATE( phi_yaw_l(1:nturbines) )
823
824	!
825	!-- Allocate 1D arrays (dimension = number of rotor segments)
826	ALLOCATE( alpha_attack(1:nsegs_max) )
827	ALLOCATE( chord(1:nsegs_max) )
828	ALLOCATE( phi_rel(1:nsegs_max) )
829	ALLOCATE( thrust_seg(1:nsegs_max) )
830	ALLOCATE( torque_seg_y(1:nsegs_max) )
831	ALLOCATE( torque_seg_z(1:nsegs_max) )
832	ALLOCATE( turb_cd(1:nsegs_max) )
833	ALLOCATE( turb_cl(1:nsegs_max) )
834	ALLOCATE( vrel(1:nsegs_max) )
835	ALLOCATE( vtheta(1:nsegs_max) )
836
837	!
838	!-- Allocate 2D arrays (dimension = number of rotor rings and segments)
839	ALLOCATE( rbx(1:nrings_max,1:nsegs_max) )
840	ALLOCATE( rby(1:nrings_max,1:nsegs_max) )
841	ALLOCATE( rbz(1:nrings_max,1:nsegs_max) )
842	ALLOCATE( thrust_ring(1:nrings_max,1:nsegs_max) )
843	ALLOCATE( torque_ring_y(1:nrings_max,1:nsegs_max) )
844	ALLOCATE( torque_ring_z(1:nrings_max,1:nsegs_max) )
845
846	!
847	!-- Allocate additional 2D arrays
848	ALLOCATE( rotx(1:nturbines,1:3) )
849	ALLOCATE( roty(1:nturbines,1:3) )
850	ALLOCATE( rotz(1:nturbines,1:3) )
851
852	!
853	!-- Allocate 3D arrays (dimension = number of grid points)
854	ALLOCATE( nac_cd_surf(nzb:nzt+1,nysg:nyng,nxlg:nxrg) )
855	ALLOCATE( rot_tend_x(nzb:nzt+1,nysg:nyng,nxlg:nxrg) )
856	ALLOCATE( rot_tend_y(nzb:nzt+1,nysg:nyng,nxlg:nxrg) )
857	ALLOCATE( rot_tend_z(nzb:nzt+1,nysg:nyng,nxlg:nxrg) )
858	ALLOCATE( thrust(nzb:nzt+1,nysg:nyng,nxlg:nxrg) )
859	ALLOCATE( torque_y(nzb:nzt+1,nysg:nyng,nxlg:nxrg) )
860	ALLOCATE( torque_z(nzb:nzt+1,nysg:nyng,nxlg:nxrg) )
861	ALLOCATE( tow_cd_surf(nzb:nzt+1,nysg:nyng,nxlg:nxrg) )
862
863	!
864	!-- Allocate additional 3D arrays
865	ALLOCATE( u_int(1:nturbines,1:nrings_max,1:nsegs_max) )
866	ALLOCATE( u_int_1_l(1:nturbines,1:nrings_max,1:nsegs_max) )
867	ALLOCATE( v_int(1:nturbines,1:nrings_max,1:nsegs_max) )
868	ALLOCATE( v_int_1_l(1:nturbines,1:nrings_max,1:nsegs_max) )
869	ALLOCATE( w_int(1:nturbines,1:nrings_max,1:nsegs_max) )
870	ALLOCATE( w_int_1_l(1:nturbines,1:nrings_max,1:nsegs_max) )
871
872	!
873	!-- All of the arrays are initialized with a value of zero:
874	i_hub(:) = 0
875	i_smear(:) = 0
876	j_hub(:) = 0
877	j_smear(:) = 0
878	k_hub(:) = 0
879	k_smear(:) = 0
880
881	torque_total(:) = 0.0_wp
882	thrust_rotor(:) = 0.0_wp
883
884	IF ( TRIM( initializing_actions ) /= 'read_restart_data' ) THEN
885	omega_gen(:) = 0.0_wp
886	omega_gen_old(:) = 0.0_wp
887	omega_gen_f(:) = 0.0_wp
888	omega_gen_f_old(:) = 0.0_wp
889	pitch_add_old(:) = 0.0_wp
890	torque_gen(:) = 0.0_wp
891	torque_gen_old(:) = 0.0_wp
892	ENDIF
893
894	yawdir(:) = 0.0_wp
895	wdir_l(:) = 0.0_wp
896	wdir(:) = 0.0_wp
897	u_inflow(:) = 0.0_wp
898	u_inflow_l(:) = 0.0_wp
899	phi_yaw_l(:) = 0.0_wp
900
901	!
902	!-- Allocate 1D arrays (dimension = number of rotor segments)
903	alpha_attack(:) = 0.0_wp
904	chord(:) = 0.0_wp
905	phi_rel(:) = 0.0_wp
906	thrust_seg(:) = 0.0_wp
907	torque_seg_y(:) = 0.0_wp
908	torque_seg_z(:) = 0.0_wp
909	turb_cd(:) = 0.0_wp
910	turb_cl(:) = 0.0_wp
911	vrel(:) = 0.0_wp
912	vtheta(:) = 0.0_wp
913
914	rbx(:,:) = 0.0_wp
915	rby(:,:) = 0.0_wp
916	rbz(:,:) = 0.0_wp
917	thrust_ring(:,:) = 0.0_wp
918	torque_ring_y(:,:) = 0.0_wp
919	torque_ring_z(:,:) = 0.0_wp
920
921	rotx(:,:) = 0.0_wp
922	roty(:,:) = 0.0_wp
923	rotz(:,:) = 0.0_wp
924
925	nac_cd_surf(:,:,:) = 0.0_wp
926	rot_tend_x(:,:,:) = 0.0_wp
927	rot_tend_y(:,:,:) = 0.0_wp
928	rot_tend_z(:,:,:) = 0.0_wp
929	thrust(:,:,:) = 0.0_wp
930	torque_y(:,:,:) = 0.0_wp
931	torque_z(:,:,:) = 0.0_wp
932	tow_cd_surf(:,:,:) = 0.0_wp
933
934	u_int(:,:,:) = 0.0_wp
935	u_int_1_l(:,:,:) = 0.0_wp
936	v_int(:,:,:) = 0.0_wp
937	v_int_1_l(:,:,:) = 0.0_wp
938	w_int(:,:,:) = 0.0_wp
939	w_int_1_l(:,:,:) = 0.0_wp
940
941
942	END SUBROUTINE wtm_init_arrays
943
944
945	!------------------------------------------------------------------------------!
946	! Description:
947	! ------------
948	!> Initialization of the wind turbine model
949	!------------------------------------------------------------------------------!
950	SUBROUTINE wtm_init
951
952
953	USE control_parameters, &
954	ONLY: dz_stretch_level_start
955
956	IMPLICIT NONE
957
958	INTEGER(iwp) :: i !< running index
959	INTEGER(iwp) :: j !< running index
960	INTEGER(iwp) :: k !< running index
961
962	!
963	!-- Help variables for the smearing function
964	REAL(wp) :: eps_kernel !<
965
966	!
967	!-- Help variables for calculation of the tower drag
968	INTEGER(iwp) :: tower_n !<
969	INTEGER(iwp) :: tower_s !<
970	!
971	!-- Help variables for the calulaction of the nacelle drag
972	INTEGER(iwp) :: i_ip !<
973	INTEGER(iwp) :: i_ipg !<
974
975	REAL(wp) :: yvalue
976	REAL(wp) :: dy_int !<
977	REAL(wp) :: dz_int !<
978
979	REAL(wp), DIMENSION(:,:), ALLOCATABLE :: circle_points !<
980
981	INTEGER(iwp), DIMENSION(:), ALLOCATABLE :: index_nacb !<
982	INTEGER(iwp), DIMENSION(:), ALLOCATABLE :: index_nacl !<
983	INTEGER(iwp), DIMENSION(:), ALLOCATABLE :: index_nacr !<
984	INTEGER(iwp), DIMENSION(:), ALLOCATABLE :: index_nact !<
985
986	ALLOCATE( index_nacb(1:nturbines) )
987	ALLOCATE( index_nacl(1:nturbines) )
988	ALLOCATE( index_nacr(1:nturbines) )
989	ALLOCATE( index_nact(1:nturbines) )
990
991	!
992	!------------------------------------------------------------------------------!
993	!-- Calculation of parameters for the regularization kernel
994	!-- (smearing of the forces)
995	!------------------------------------------------------------------------------!
996	!
997	!-- In the following, some of the required parameters for the smearing will
998	!-- be calculated:
999
1000	!-- The kernel is set equal to twice the grid spacing which has turned out to
1001	!-- be a reasonable value (see e.g. Troldborg et al. (2013), Wind Energy,
1002	!-- DOI: 10.1002/we.1608):
1003	eps_kernel = 2.0_wp * dx
1004	!
1005	!-- The zero point (eps_min) of the polynomial function must be the following
1006	!-- if the integral of the polynomial function (for values < eps_min) shall
1007	!-- be equal to the integral of the Gaussian function used before:
1008	eps_min = ( 105.0_wp / 32.0_wp )*( 1.0_wp / 3.0_wp ) &
1009	pi*( 1.0_wp / 6.0_wp ) eps_kernel
1010	!
1011	!-- Stretching (non-uniform grid spacing) is not considered in the wind
1012	!-- turbine model. Therefore, vertical stretching has to be applied above
1013	!-- the area where the wtm is active. ABS (...) is required because the
1014	!-- default value of dz_stretch_level_start is -9999999.9_wp (negative).
1015	IF ( ABS( dz_stretch_level_start(1) ) <= MAXVAL(rcz) + MAXVAL(rr) + &
1016	eps_min) THEN
1017	WRITE( message_string, * ) 'The lowest level where vertical ', &
1018	'stretching is applied &have to be ', &
1019	'greater than ', MAXVAL(rcz) + &
1020	MAXVAL(rr) + eps_min
1021	CALL message( 'wtm_init', 'PA0484', 1, 2, 0, 6, 0 )
1022	ENDIF
1023	!
1024	!-- Square of eps_min:
1025	eps_min2 = eps_min**2
1026	!
1027	!-- Parameters in the polynomial function:
1028	pol_a = 1.0_wp / eps_min**4
1029	pol_b = 2.0_wp / eps_min**2
1030	!
1031	!-- Normalization factor which is the inverse of the integral of the smearing
1032	!-- function:
1033	eps_factor = 105.0_wp / ( 32.0_wp * pi * eps_min**3 )
1034
1035	!-- Change tilt angle to rad:
1036	tilt = tilt * pi / 180.0_wp
1037
1038	!
1039	!-- Change yaw angle to rad:
1040	IF ( TRIM( initializing_actions ) /= 'read_restart_data' ) THEN
1041	phi_yaw(:) = phi_yaw(:) * pi / 180.0_wp
1042	ENDIF
1043
1044
1045	DO inot = 1, nturbines
1046	!
1047	!-- Rotate the rotor coordinates in case yaw and tilt are defined
1048	CALL wtm_rotate_rotor( inot )
1049
1050	!
1051	!-- Determine the indices of the hub height
1052	i_hub(inot) = INT( rcx(inot) / dx )
1053	j_hub(inot) = INT( ( rcy(inot) + 0.5_wp * dy ) / dy )
1054	k_hub(inot) = INT( ( rcz(inot) + 0.5_wp * dz(1) ) / dz(1) )
1055
1056	!
1057	!-- Determining the area to which the smearing of the forces is applied.
1058	!-- As smearing now is effectively applied only for distances smaller than
1059	!-- eps_min, the smearing area can be further limited and regarded as a
1060	!-- function of eps_min:
1061	i_smear(inot) = CEILING( ( rr(inot) + eps_min ) / dx )
1062	j_smear(inot) = CEILING( ( rr(inot) + eps_min ) / dy )
1063	k_smear(inot) = CEILING( ( rr(inot) + eps_min ) / dz(1) )
1064
1065	ENDDO
1066
1067	!
1068	!-- Call the wtm_init_speed_control subroutine and calculate the local
1069	!-- omega_rot for the respective processor.
1070	IF ( speed_control) THEN
1071
1072	CALL wtm_speed_control
1073
1074	IF ( TRIM( initializing_actions ) == 'read_restart_data' ) THEN
1075
1076	DO inot = 1, nturbines
1077
1078	IF ( nxl > i_hub(inot) ) THEN
1079	torque_gen(inot) = 0.0_wp
1080	omega_gen_f(inot) = 0.0_wp
1081	omega_rot_l(inot) = 0.0_wp
1082	ENDIF
1083
1084	IF ( nxr < i_hub(inot) ) THEN
1085	torque_gen(inot) = 0.0_wp
1086	omega_gen_f(inot) = 0.0_wp
1087	omega_rot_l(inot) = 0.0_wp
1088	ENDIF
1089
1090	IF ( nys > j_hub(inot) ) THEN
1091	torque_gen(inot) = 0.0_wp
1092	omega_gen_f(inot) = 0.0_wp
1093	omega_rot_l(inot) = 0.0_wp
1094	ENDIF
1095
1096	IF ( nyn < j_hub(inot) ) THEN
1097	torque_gen(inot) = 0.0_wp
1098	omega_gen_f(inot) = 0.0_wp
1099	omega_rot_l(inot) = 0.0_wp
1100	ENDIF
1101
1102	IF ( ( nxl <= i_hub(inot) ) .AND. ( nxr >= i_hub(inot) ) ) THEN
1103	IF ( ( nys <= j_hub(inot) ) .AND. ( nyn >= j_hub(inot) ) ) THEN
1104
1105	omega_rot_l(inot) = omega_gen(inot) / gear_ratio
1106
1107	ENDIF
1108	ENDIF
1109
1110	END DO
1111
1112	ENDIF
1113
1114	ENDIF
1115
1116	!
1117	!------------------------------------------------------------------------------!
1118	!-- Determine the area within each grid cell that overlaps with the area
1119	!-- of the nacelle and the tower (needed for calculation of the forces)
1120	!------------------------------------------------------------------------------!
1121	!
1122	!-- Note: so far this is only a 2D version, in that the mean flow is
1123	!-- perpendicular to the rotor area.
1124
1125	!
1126	!-- Allocation of the array containing information on the intersection points
1127	!-- between rotor disk and the numerical grid:
1128	upper_end = ( ny + 1 ) * 10000
1129
1130	ALLOCATE( circle_points(1:2,1:upper_end) )
1131
1132	circle_points(:,:) = 0.0_wp
1133
1134
1135	DO inot = 1, nturbines ! loop over number of turbines
1136	!
1137	!-- Determine the grid index (u-grid) that corresponds to the location of
1138	!-- the rotor center (reduces the amount of calculations in the case that
1139	!-- the mean flow is perpendicular to the rotor area):
1140	i = i_hub(inot)
1141
1142	!
1143	!-- Determine the left and the right edge of the nacelle (corresponding
1144	!-- grid point indices):
1145	index_nacl(inot) = INT( ( rcy(inot) - rnac(inot) + 0.5_wp * dy ) / dy )
1146	index_nacr(inot) = INT( ( rcy(inot) + rnac(inot) + 0.5_wp * dy ) / dy )
1147	!
1148	!-- Determine the bottom and the top edge of the nacelle (corresponding
1149	!-- grid point indices).The grid point index has to be increased by 1, as
1150	!-- the first level for the u-component (index 0) is situated below the
1151	!-- surface. All points between z=0 and z=dz/s would already be contained
1152	!-- in grid box 1.
1153	index_nacb(inot) = INT( ( rcz(inot) - rnac(inot) ) / dz(1) ) + 1
1154	index_nact(inot) = INT( ( rcz(inot) + rnac(inot) ) / dz(1) ) + 1
1155
1156	!
1157	!-- Determine the indices of the grid boxes containing the left and
1158	!-- the right boundaries of the tower:
1159	tower_n = ( rcy(inot) + 0.5_wp * dtow(inot) - 0.5_wp * dy ) / dy
1160	tower_s = ( rcy(inot) - 0.5_wp * dtow(inot) - 0.5_wp * dy ) / dy
1161
1162	!
1163	!-- Determine the fraction of the grid box area overlapping with the tower
1164	!-- area and multiply it with the drag of the tower:
1165	IF ( ( nxlg <= i ) .AND. ( nxrg >= i ) ) THEN
1166
1167	DO j = nys, nyn
1168	!
1169	!-- Loop from south to north boundary of tower
1170	IF ( ( j >= tower_s ) .AND. ( j <= tower_n ) ) THEN
1171
1172	DO k = nzb, nzt
1173
1174	IF ( k == k_hub(inot) ) THEN
1175	IF ( tower_n - tower_s >= 1 ) THEN
1176	!
1177	!-- leftmost and rightmost grid box:
1178	IF ( j == tower_s ) THEN
1179	tow_cd_surf(k,j,i) = ( rcz(inot) - &
1180	( k_hub(inot) * dz(1) - 0.5_wp * dz(1) ) )*& ! extension in z-direction
1181	( ( tower_s + 1.0_wp + 0.5_wp ) * dy - &
1182	( rcy(inot) - 0.5_wp * dtow(inot) ) ) * & ! extension in y-direction
1183	turb_cd_tower(inot)
1184	ELSEIF ( j == tower_n ) THEN
1185	tow_cd_surf(k,j,i) = ( rcz(inot) - &
1186	( k_hub(inot) * dz(1) - 0.5_wp * dz(1) ) )*& ! extension in z-direction
1187	( ( rcy(inot) + 0.5_wp * dtow(inot) ) - &
1188	( tower_n + 0.5_wp ) * dy ) * & ! extension in y-direction
1189	turb_cd_tower(inot)
1190	!
1191	!-- grid boxes inbetween
1192	!-- (where tow_cd_surf = grid box area):
1193	ELSE
1194	tow_cd_surf(k,j,i) = ( rcz(inot) - &
1195	( k_hub(inot) * dz(1) - 0.5_wp * dz(1) ) )*&
1196	dy * turb_cd_tower(inot)
1197	ENDIF
1198	!
1199	!-- tower lies completely within one grid box:
1200	ELSE
1201	tow_cd_surf(k,j,i) = ( rcz(inot) - ( k_hub(inot) * &
1202	dz(1) - 0.5_wp * dz(1) ) ) * &
1203	dtow(inot) * turb_cd_tower(inot)
1204	ENDIF
1205	!
1206	!-- In case that k is smaller than k_hub the following actions
1207	!-- are carried out:
1208	ELSEIF ( k < k_hub(inot) ) THEN
1209
1210	IF ( ( tower_n - tower_s ) >= 1 ) THEN
1211	!
1212	!-- leftmost and rightmost grid box:
1213	IF ( j == tower_s ) THEN
1214	tow_cd_surf(k,j,i) = dz(1) * ( &
1215	( tower_s + 1 + 0.5_wp ) * dy - &
1216	( rcy(inot) - 0.5_wp * dtow(inot) ) &
1217	) * turb_cd_tower(inot)
1218	ELSEIF ( j == tower_n ) THEN
1219	tow_cd_surf(k,j,i) = dz(1) * ( &
1220	( rcy(inot) + 0.5_wp * dtow(inot) ) - &
1221	( tower_n + 0.5_wp ) * dy &
1222	) * turb_cd_tower(inot)
1223	!
1224	!-- grid boxes inbetween
1225	!-- (where tow_cd_surf = grid box area):
1226	ELSE
1227	tow_cd_surf(k,j,i) = dz(1) * dy * &
1228	turb_cd_tower(inot)
1229	ENDIF
1230	!
1231	!-- tower lies completely within one grid box:
1232	ELSE
1233	tow_cd_surf(k,j,i) = dz(1) * dtow(inot) * &
1234	turb_cd_tower(inot)
1235	ENDIF ! end if larger than grid box
1236
1237	ENDIF ! end if k == k_hub
1238
1239	ENDDO ! end loop over k
1240
1241	ENDIF ! end if inside north and south boundary of tower
1242
1243	ENDDO ! end loop over j
1244
1245	ENDIF ! end if hub inside domain + ghostpoints
1246
1247
1248	CALL exchange_horiz( tow_cd_surf, nbgp )
1249
1250	!
1251	!-- Calculation of the nacelle area
1252	!-- CAUTION: Currently disabled due to segmentation faults on the FLOW HPC
1253	!-- cluster (Oldenburg)
1254	!!
1255	!!-- Tabulate the points on the circle that are required in the following for
1256	!!-- the calculation of the Riemann integral (node points; they are called
1257	!!-- circle_points in the following):
1258	!
1259	! dy_int = dy / 10000.0_wp
1260	!
1261	! DO i_ip = 1, upper_end
1262	! yvalue = dy_int * ( i_ip - 0.5_wp ) + 0.5_wp * dy !<--- segmentation fault
1263	! sqrt_arg = rnac(inot)2 - ( yvalue - rcy(inot) )2 !<--- segmentation fault
1264	! IF ( sqrt_arg >= 0.0_wp ) THEN
1265	!!
1266	!!-- bottom intersection point
1267	! circle_points(1,i_ip) = rcz(inot) - SQRT( sqrt_arg )
1268	!!
1269	!!-- top intersection point
1270	! circle_points(2,i_ip) = rcz(inot) + SQRT( sqrt_arg ) !<--- segmentation fault
1271	! ELSE
1272	! circle_points(:,i_ip) = -111111 !<--- segmentation fault
1273	! ENDIF
1274	! ENDDO
1275	!
1276	!
1277	! DO j = nys, nyn
1278	!!
1279	!!-- In case that the grid box is located completely outside the nacelle
1280	!!-- (y) it can automatically be stated that there is no overlap between
1281	!!-- the grid box and the nacelle and consequently we can set
1282	!!-- nac_cd_surf(:,j,i) = 0.0:
1283	! IF ( ( j >= index_nacl(inot) ) .AND. ( j <= index_nacr(inot) ) ) THEN
1284	! DO k = nzb+1, nzt
1285	!!
1286	!!-- In case that the grid box is located completely outside the
1287	!!-- nacelle (z) it can automatically be stated that there is no
1288	!!-- overlap between the grid box and the nacelle and consequently
1289	!!-- we can set nac_cd_surf(k,j,i) = 0.0:
1290	! IF ( ( k >= index_nacb(inot) ) .OR. &
1291	! ( k <= index_nact(inot) ) ) THEN
1292	!!
1293	!!-- For all other cases Riemann integrals are calculated.
1294	!!-- Here, the points on the circle that have been determined
1295	!!-- above are used in order to calculate the overlap between the
1296	!!-- gridbox and the nacelle area (area approached by 10000
1297	!!-- rectangulars dz_int * dy_int):
1298	! DO i_ipg = 1, 10000
1299	! dz_int = dz
1300	! i_ip = j * 10000 + i_ipg
1301	!!
1302	!!-- Determine the vertical extension dz_int of the circle
1303	!!-- within the current grid box:
1304	! IF ( ( circle_points(2,i_ip) < zw(k) ) .AND. & !<--- segmentation fault
1305	! ( circle_points(2,i_ip) >= zw(k-1) ) ) THEN
1306	! dz_int = dz_int - & !<--- segmentation fault
1307	! ( zw(k) - circle_points(2,i_ip) )
1308	! ENDIF
1309	! IF ( ( circle_points(1,i_ip) <= zw(k) ) .AND. & !<--- segmentation fault
1310	! ( circle_points(1,i_ip) > zw(k-1) ) ) THEN
1311	! dz_int = dz_int - &
1312	! ( circle_points(1,i_ip) - zw(k-1) )
1313	! ENDIF
1314	! IF ( zw(k-1) > circle_points(2,i_ip) ) THEN
1315	! dz_int = 0.0_wp
1316	! ENDIF
1317	! IF ( zw(k) < circle_points(1,i_ip) ) THEN
1318	! dz_int = 0.0_wp
1319	! ENDIF
1320	! IF ( ( nxlg <= i ) .AND. ( nxrg >= i ) ) THEN
1321	! nac_cd_surf(k,j,i) = nac_cd_surf(k,j,i) + & !<--- segmentation fault
1322	! dy_int * dz_int * turb_cd_nacelle(inot)
1323	! ENDIF
1324	! ENDDO
1325	! ENDIF
1326	! ENDDO
1327	! ENDIF
1328	!
1329	! ENDDO
1330	!
1331	! CALL exchange_horiz( nac_cd_surf, nbgp ) !<--- segmentation fault
1332
1333	ENDDO ! end of loop over turbines
1334
1335	tow_cd_surf = tow_cd_surf / ( dx * dy * dz(1) ) ! Normalize tower drag
1336	nac_cd_surf = nac_cd_surf / ( dx * dy * dz(1) ) ! Normalize nacelle drag
1337
1338	CALL wtm_read_blade_tables
1339
1340	END SUBROUTINE wtm_init
1341
1342
1343	!------------------------------------------------------------------------------!
1344	! Description:
1345	! ------------
1346	!> Read in layout of the rotor blade , the lift and drag tables
1347	!> and the distribution of lift and drag tables along the blade
1348	!------------------------------------------------------------------------------!
1349	!
1350	SUBROUTINE wtm_read_blade_tables
1351
1352
1353	IMPLICIT NONE
1354
1355	INTEGER(iwp) :: ii !< running index
1356	INTEGER(iwp) :: jj !< running index
1357
1358	INTEGER(iwp) :: ierrn !<
1359
1360	CHARACTER(200) :: chmess !< Read in string
1361
1362	INTEGER(iwp) :: dlen !< no. rows of local table
1363	INTEGER(iwp) :: dlenbl !< no. rows of cd, cl table
1364	INTEGER(iwp) :: ialpha !< table position of current alpha value
1365	INTEGER(iwp) :: iialpha !<
1366	INTEGER(iwp) :: iir !<
1367	INTEGER(iwp) :: radres !< radial resolution
1368	INTEGER(iwp) :: t1 !< no. of airfoil
1369	INTEGER(iwp) :: t2 !< no. of airfoil
1370	INTEGER(iwp) :: trow !<
1371	INTEGER(iwp) :: dlenbl_int !< no. rows of interpolated cd, cl tables
1372
1373	REAL(wp) :: alpha_attack_i !<
1374	REAL(wp) :: weight_a !<
1375	REAL(wp) :: weight_b !<
1376
1377	INTEGER(iwp), DIMENSION(:), ALLOCATABLE :: ttoint1 !<
1378	INTEGER(iwp), DIMENSION(:), ALLOCATABLE :: ttoint2 !<
1379
1380	REAL(wp), DIMENSION(:), ALLOCATABLE :: turb_cd_sel1 !<
1381	REAL(wp), DIMENSION(:), ALLOCATABLE :: turb_cd_sel2 !<
1382	REAL(wp), DIMENSION(:), ALLOCATABLE :: turb_cl_sel1 !<
1383	REAL(wp), DIMENSION(:), ALLOCATABLE :: turb_cl_sel2 !<
1384	REAL(wp), DIMENSION(:), ALLOCATABLE :: read_cl_cd !< read in var array
1385
1386	REAL(wp), DIMENSION(:), ALLOCATABLE :: alpha_attack_tab !<
1387	REAL(wp), DIMENSION(:), ALLOCATABLE :: trad1 !<
1388	REAL(wp), DIMENSION(:), ALLOCATABLE :: trad2 !<
1389	REAL(wp), DIMENSION(:,:), ALLOCATABLE :: turb_cd_table !<
1390	REAL(wp), DIMENSION(:,:), ALLOCATABLE :: turb_cl_table !<
1391
1392	ALLOCATE ( read_cl_cd(1:2*nairfoils+1) )
1393
1394	!
1395	!-- Read in the distribution of lift and drag tables along the blade, the
1396	!-- layout of the rotor blade and the lift and drag tables:
1397
1398	OPEN ( 90, FILE='WTM_DATA', STATUS='OLD', FORM='FORMATTED', IOSTAT=ierrn )
1399
1400	IF ( ierrn /= 0 ) THEN
1401	message_string = 'file WTM_DATA does not exist'
1402	CALL message( 'wtm_init', 'PA0464', 1, 2, 0, 6, 0 )
1403	ENDIF
1404	!
1405	!-- Read distribution table:
1406
1407	dlen = 0
1408
1409	READ ( 90, '(3/)' )
1410
1411	rloop3: DO
1412	READ ( 90, *, IOSTAT=ierrn ) chmess
1413	IF ( ierrn < 0 .OR. chmess == '#' .OR. chmess == '') EXIT rloop3
1414	dlen = dlen + 1
1415	ENDDO rloop3
1416
1417	ALLOCATE( trad1(1:dlen), trad2(1:dlen), ttoint1(1:dlen), ttoint2(1:dlen))
1418
1419	DO jj = 1,dlen+1
1420	BACKSPACE ( 90, IOSTAT=ierrn )
1421	ENDDO
1422
1423	DO jj = 1,dlen
1424	READ ( 90, * ) trad1(jj), trad2(jj), ttoint1(jj), ttoint2(jj)
1425	ENDDO
1426
1427	!
1428	!-- Read layout table:
1429
1430	dlen = 0
1431
1432	READ ( 90, '(3/)')
1433
1434	rloop1: DO
1435	READ ( 90, *, IOSTAT=ierrn ) chmess
1436	IF ( ierrn < 0 .OR. chmess == '#' .OR. chmess == '') EXIT rloop1
1437	dlen = dlen + 1
1438	ENDDO rloop1
1439
1440	ALLOCATE( lrd(1:dlen), ard(1:dlen), crd(1:dlen) )
1441	DO jj = 1, dlen+1
1442	BACKSPACE ( 90, IOSTAT=ierrn )
1443	ENDDO
1444	DO jj = 1, dlen
1445	READ ( 90, * ) lrd(jj), ard(jj), crd(jj)
1446	ENDDO
1447
1448	!
1449	!-- Read tables (turb_cl(alpha),turb_cd(alpha) for the different profiles:
1450
1451	dlen = 0
1452
1453	READ ( 90, '(3/)' )
1454
1455	rloop2: DO
1456	READ ( 90, *, IOSTAT=ierrn ) chmess
1457	IF ( ierrn < 0 .OR. chmess == '#' .OR. chmess == '') EXIT rloop2
1458	dlen = dlen + 1
1459	ENDDO rloop2
1460
1461	ALLOCATE( alpha_attack_tab(1:dlen), turb_cl_table(1:dlen,1:nairfoils), &
1462	turb_cd_table(1:dlen,1:nairfoils) )
1463
1464	DO jj = 1,dlen+1
1465	BACKSPACE ( 90, IOSTAT=ierrn )
1466	ENDDO
1467
1468	DO jj = 1,dlen
1469	READ ( 90, * ) read_cl_cd
1470	alpha_attack_tab(jj) = read_cl_cd(1)
1471	DO ii= 1, nairfoils
1472	turb_cl_table(jj,ii) = read_cl_cd(ii*2)
1473	turb_cd_table(jj,ii) = read_cl_cd(ii*2+1)
1474	ENDDO
1475
1476	ENDDO
1477
1478	dlenbl = dlen
1479
1480	CLOSE ( 90 )
1481
1482	!
1483	!-- For each possible radial position (resolution: 0.1 m --> 631 values if rr(1)=63m)
1484	!-- and each possible angle of attack (resolution: 0.1 degrees --> 3601 values!)
1485	!-- determine the lift and drag coefficient by interpolating between the
1486	!-- tabulated values of each table (interpolate to current angle of attack)
1487	!-- and between the tables (interpolate to current radial position):
1488
1489	ALLOCATE( turb_cl_sel1(1:dlenbl) )
1490	ALLOCATE( turb_cl_sel2(1:dlenbl) )
1491	ALLOCATE( turb_cd_sel1(1:dlenbl) )
1492	ALLOCATE( turb_cd_sel2(1:dlenbl) )
1493
1494	radres = INT( rr(1) * 10.0_wp ) + 1_iwp
1495	dlenbl_int = INT( 360.0_wp / accu_cl_cd_tab ) + 1_iwp
1496
1497	ALLOCATE( turb_cl_tab(1:dlenbl_int,1:radres) )
1498	ALLOCATE( turb_cd_tab(1:dlenbl_int,1:radres) )
1499
1500	DO iir = 1, radres ! loop over radius
1501
1502	cur_r = ( iir - 1_iwp ) * 0.1_wp
1503	!
1504	!-- Find position in table 1
1505	lct = MINLOC( ABS( trad1 - cur_r ) )
1506	! lct(1) = lct(1)
1507
1508	IF ( ( trad1(lct(1)) - cur_r ) .GT. 0.0 ) THEN
1509	lct(1) = lct(1) - 1
1510	ENDIF
1511
1512	trow = lct(1)
1513	!
1514	!-- Calculate weights for radius interpolation
1515	weight_a = ( trad2(trow) - cur_r ) / ( trad2(trow) - trad1(trow) )
1516	weight_b = ( cur_r - trad1(trow) ) / ( trad2(trow) - trad1(trow) )
1517	t1 = ttoint1(trow)
1518	t2 = ttoint2(trow)
1519
1520	IF ( t1 .EQ. t2 ) THEN ! if both are the same, the weights are NaN
1521	weight_a = 0.5_wp ! then do interpolate in between same twice
1522	weight_b = 0.5_wp ! using 0.5 as weight
1523	ENDIF
1524
1525	IF ( t1 == 0 .AND. t2 == 0 ) THEN
1526	turb_cd_sel1 = 0.0_wp
1527	turb_cd_sel2 = 0.0_wp
1528	turb_cl_sel1 = 0.0_wp
1529	turb_cl_sel2 = 0.0_wp
1530
1531	turb_cd_tab(1,iir) = 0.0_wp ! For -180Â° (iialpha=1) the values
1532	turb_cl_tab(1,iir) = 0.0_wp ! for each radius has to be set
1533	! explicitly
1534	ELSE
1535	turb_cd_sel1 = turb_cd_table(:,t1)
1536	turb_cd_sel2 = turb_cd_table(:,t2)
1537	turb_cl_sel1 = turb_cl_table(:,t1)
1538	turb_cl_sel2 = turb_cl_table(:,t2)
1539	!
1540	!-- For -180Â° (iialpha=1) the values for each radius has to be set
1541	!-- explicitly
1542	turb_cd_tab(1,iir) = ( weight_a * turb_cd_table(1,t1) + weight_b &
1543	* turb_cd_table(1,t2) )
1544	turb_cl_tab(1,iir) = ( weight_a * turb_cl_table(1,t1) + weight_b &
1545	* turb_cl_table(1,t2) )
1546	ENDIF
1547
1548	DO iialpha = 2, dlenbl_int ! loop over angles
1549
1550	alpha_attack_i = -180.0_wp + REAL( iialpha-1 ) * accu_cl_cd_tab
1551	ialpha = 1
1552
1553	DO WHILE ( ( alpha_attack_i > alpha_attack_tab(ialpha) ) .AND. (ialpha <= dlen ) )
1554	ialpha = ialpha + 1
1555	ENDDO
1556
1557	!
1558	!-- Interpolation of lift and drag coefficiencts on fine grid of radius
1559	!-- segments and angles of attack
1560	turb_cl_tab(iialpha,iir) = ( alpha_attack_tab(ialpha) - &
1561	alpha_attack_i ) / &
1562	( alpha_attack_tab(ialpha) - &
1563	alpha_attack_tab(ialpha-1) ) * &
1564	( weight_a * turb_cl_sel1(ialpha-1) + &
1565	weight_b * turb_cl_sel2(ialpha-1) ) +&
1566	( alpha_attack_i - &
1567	alpha_attack_tab(ialpha-1) ) / &
1568	( alpha_attack_tab(ialpha) - &
1569	alpha_attack_tab(ialpha-1) ) * &
1570	( weight_a * turb_cl_sel1(ialpha) + &
1571	weight_b * turb_cl_sel2(ialpha) )
1572	turb_cd_tab(iialpha,iir) = ( alpha_attack_tab(ialpha) - &
1573	alpha_attack_i ) / &
1574	( alpha_attack_tab(ialpha) - &
1575	alpha_attack_tab(ialpha-1) ) * &
1576	( weight_a * turb_cd_sel1(ialpha-1) + &
1577	weight_b * turb_cd_sel2(ialpha-1) ) +&
1578	( alpha_attack_i - &
1579	alpha_attack_tab(ialpha-1) ) / &
1580	( alpha_attack_tab(ialpha) - &
1581	alpha_attack_tab(ialpha-1) ) * &
1582	( weight_a * turb_cd_sel1(ialpha) + &
1583	weight_b * turb_cd_sel2(ialpha) )
1584
1585	ENDDO ! end loop over angles of attack
1586
1587	ENDDO ! end loop over radius
1588
1589
1590	END SUBROUTINE wtm_read_blade_tables
1591
1592
1593	!------------------------------------------------------------------------------!
1594	! Description:
1595	! ------------
1596	!> The projection matrix for the coordinate system of therotor disc in respect
1597	!> to the yaw and tilt angle of the rotor is calculated
1598	!------------------------------------------------------------------------------!
1599	SUBROUTINE wtm_rotate_rotor( inot )
1600
1601
1602	IMPLICIT NONE
1603
1604	INTEGER(iwp) :: inot
1605	!
1606	!-- Calculation of the rotation matrix for the application of the tilt to
1607	!-- the rotors
1608	rot_eigen_rad(1) = SIN( phi_yaw(inot) ) ! x-component of the radial eigenvector
1609	rot_eigen_rad(2) = COS( phi_yaw(inot) ) ! y-component of the radial eigenvector
1610	rot_eigen_rad(3) = 0.0_wp ! z-component of the radial eigenvector
1611
1612	rot_eigen_azi(1) = 0.0_wp ! x-component of the azimuth eigenvector
1613	rot_eigen_azi(2) = 0.0_wp ! y-component of the azimuth eigenvector
1614	rot_eigen_azi(3) = 1.0_wp ! z-component of the azimuth eigenvector
1615
1616	rot_eigen_nor(1) = COS( phi_yaw(inot) ) ! x-component of the normal eigenvector
1617	rot_eigen_nor(2) = -SIN( phi_yaw(inot) ) ! y-component of the normal eigenvector
1618	rot_eigen_nor(3) = 0.0_wp ! z-component of the normal eigenvector
1619
1620	!
1621	!-- Calculation of the coordinate transformation matrix to apply a tilt to
1622	!-- the rotor. If tilt = 0, rot_coord_trans is a unit matrix.
1623
1624	rot_coord_trans(inot,1,1) = rot_eigen_rad(1)*2 &
1625	( 1.0_wp - COS( tilt ) ) + COS( tilt )
1626	rot_coord_trans(inot,1,2) = rot_eigen_rad(1) * rot_eigen_rad(2) * &
1627	( 1.0_wp - COS( tilt ) ) - &
1628	rot_eigen_rad(3) * SIN( tilt )
1629	rot_coord_trans(inot,1,3) = rot_eigen_rad(1) * rot_eigen_rad(3) * &
1630	( 1.0_wp - COS( tilt ) ) + &
1631	rot_eigen_rad(2) * SIN( tilt )
1632	rot_coord_trans(inot,2,1) = rot_eigen_rad(2) * rot_eigen_rad(1) * &
1633	( 1.0_wp - COS( tilt ) ) + &
1634	rot_eigen_rad(3) * SIN( tilt )
1635	rot_coord_trans(inot,2,2) = rot_eigen_rad(2)*2 &
1636	( 1.0_wp - COS( tilt ) ) + COS( tilt )
1637	rot_coord_trans(inot,2,3) = rot_eigen_rad(2) * rot_eigen_rad(3) * &
1638	( 1.0_wp - COS( tilt ) ) - &
1639	rot_eigen_rad(1) * SIN( tilt )
1640	rot_coord_trans(inot,3,1) = rot_eigen_rad(3) * rot_eigen_rad(1) * &
1641	( 1.0_wp - COS( tilt ) ) - &
1642	rot_eigen_rad(2) * SIN( tilt )
1643	rot_coord_trans(inot,3,2) = rot_eigen_rad(3) * rot_eigen_rad(2) * &
1644	( 1.0_wp - COS( tilt ) ) + &
1645	rot_eigen_rad(1) * SIN( tilt )
1646	rot_coord_trans(inot,3,3) = rot_eigen_rad(3)*2 &
1647	( 1.0_wp - COS( tilt ) ) + COS( tilt )
1648
1649	!
1650	!-- Vectors for the Transformation of forces from the rotor's spheric
1651	!-- coordinate system to the cartesian coordinate system
1652	rotx(inot,:) = MATMUL( rot_coord_trans(inot,:,:), rot_eigen_nor )
1653	roty(inot,:) = MATMUL( rot_coord_trans(inot,:,:), rot_eigen_rad )
1654	rotz(inot,:) = MATMUL( rot_coord_trans(inot,:,:), rot_eigen_azi )
1655
1656	END SUBROUTINE wtm_rotate_rotor
1657
1658
1659	!------------------------------------------------------------------------------!
1660	! Description:
1661	! ------------
1662	!> Calculation of the forces generated by the wind turbine
1663	!------------------------------------------------------------------------------!
1664	SUBROUTINE wtm_forces
1665
1666
1667	IMPLICIT NONE
1668
1669	CHARACTER (LEN=4) :: turbine_id
1670
1671	INTEGER(iwp) :: i, j, k !< loop indices
1672	INTEGER(iwp) :: inot !< turbine loop index (turbine id)
1673	INTEGER(iwp) :: iialpha, iir !<
1674	INTEGER(iwp) :: rseg, rseg_int !<
1675	INTEGER(iwp) :: ring, ring_int !<
1676	INTEGER(iwp) :: ii, jj, kk !<
1677
1678	REAL(wp) :: flag !< flag to mask topography grid points
1679	REAL(wp) :: sin_rot, cos_rot !<
1680	REAL(wp) :: sin_yaw, cos_yaw !<
1681
1682	REAL(wp) :: aa, bb, cc, dd !< interpolation distances
1683	REAL(wp) :: gg !< interpolation volume var
1684
1685	REAL(wp) :: dist_u_3d, dist_v_3d, dist_w_3d !< smearing distances
1686
1687
1688	!
1689	! Variables for pitch control
1690	REAL(wp) :: torque_max=0.0_wp
1691	LOGICAL :: pitch_sw=.FALSE.
1692
1693	INTEGER(iwp), DIMENSION(1) :: lct=0
1694	REAL(wp), DIMENSION(1) :: rad_d=0.0_wp
1695
1696	REAL(wp) :: tl_factor !< factor for tip loss correction
1697
1698
1699	CALL cpu_log( log_point_s(61), 'wtm_forces', 'start' )
1700
1701
1702	IF ( simulated_time >= time_turbine_on ) THEN
1703
1704	!
1705	!-- Set forces to zero for each new time step:
1706	thrust(:,:,:) = 0.0_wp
1707	torque_y(:,:,:) = 0.0_wp
1708	torque_z(:,:,:) = 0.0_wp
1709	torque_total(:) = 0.0_wp
1710	rot_tend_x(:,:,:) = 0.0_wp
1711	rot_tend_y(:,:,:) = 0.0_wp
1712	rot_tend_z(:,:,:) = 0.0_wp
1713	thrust_rotor(:) = 0.0_wp
1714	!
1715	!-- Loop over number of turbines:
1716	DO inot = 1, nturbines
1717
1718	cos_yaw = COS(phi_yaw(inot))
1719	sin_yaw = SIN(phi_yaw(inot))
1720	!
1721	!-- Loop over rings of each turbine:
1722	DO ring = 1, nrings(inot)
1723
1724	thrust_seg(:) = 0.0_wp
1725	torque_seg_y(:) = 0.0_wp
1726	torque_seg_z(:) = 0.0_wp
1727	!
1728	!-- Determine distance between each ring (center) and the hub:
1729	cur_r = (ring - 0.5_wp) * delta_r(inot)
1730
1731	!
1732	!-- Loop over segments of each ring of each turbine:
1733	DO rseg = 1, nsegs(ring,inot)
1734	!
1735	!-- !-----------------------------------------------------------!
1736	!-- !-- Determine coordinates of the ring segments --!
1737	!-- !-----------------------------------------------------------!
1738	!
1739	!-- Determine angle of ring segment towards zero degree angle of
1740	!-- rotor system (at zero degree rotor direction vectors aligned
1741	!-- with y-axis):
1742	phi_rotor = rseg * 2.0_wp * pi / nsegs(ring,inot)
1743	cos_rot = COS( phi_rotor )
1744	sin_rot = SIN( phi_rotor )
1745
1746	!-- Now the direction vectors can be determined with respect to
1747	!-- the yaw and tilt angle:
1748	re(1) = cos_rot * sin_yaw
1749	re(2) = cos_rot * cos_yaw
1750	re(3) = sin_rot
1751
1752	rote = MATMUL( rot_coord_trans(inot,:,:), re )
1753	!
1754	!-- Coordinates of the single segments (center points):
1755	rbx(ring,rseg) = rcx(inot) + cur_r * rote(1)
1756	rby(ring,rseg) = rcy(inot) + cur_r * rote(2)
1757	rbz(ring,rseg) = rcz(inot) + cur_r * rote(3)
1758
1759	!-- !-----------------------------------------------------------!
1760	!-- !-- Interpolation of the velocity components from the --!
1761	!-- !-- cartesian grid point to the coordinates of each ring --!
1762	!-- !-- segment (follows a method used in the particle model) --!
1763	!-- !-----------------------------------------------------------!
1764
1765	u_int(inot,ring,rseg) = 0.0_wp
1766	u_int_1_l(inot,ring,rseg) = 0.0_wp
1767
1768	v_int(inot,ring,rseg) = 0.0_wp
1769	v_int_1_l(inot,ring,rseg) = 0.0_wp
1770
1771	w_int(inot,ring,rseg) = 0.0_wp
1772	w_int_1_l(inot,ring,rseg) = 0.0_wp
1773
1774	!
1775	!-- Interpolation of the u-component:
1776
1777	ii = rbx(ring,rseg) * ddx
1778	jj = ( rby(ring,rseg) - 0.5_wp * dy ) * ddy
1779	kk = ( rbz(ring,rseg) + 0.5_wp * dz(1) ) / dz(1)
1780	!
1781	!-- Interpolate only if all required information is available on
1782	!-- the current PE:
1783	IF ( ( ii >= nxl ) .AND. ( ii <= nxr ) ) THEN
1784	IF ( ( jj >= nys ) .AND. ( jj <= nyn ) ) THEN
1785
1786	aa = ( ( ii + 1 ) * dx - rbx(ring,rseg) ) * &
1787	( ( jj + 1 + 0.5_wp ) * dy - rby(ring,rseg) )
1788	bb = ( rbx(ring,rseg) - ii * dx ) * &
1789	( ( jj + 1 + 0.5_wp ) * dy - rby(ring,rseg) )
1790	cc = ( ( ii+1 ) * dx - rbx(ring,rseg) ) * &
1791	( rby(ring,rseg) - ( jj + 0.5_wp ) * dy )
1792	dd = ( rbx(ring,rseg) - ii * dx ) * &
1793	( rby(ring,rseg) - ( jj + 0.5_wp ) * dy )
1794	gg = dx * dy
1795
1796	u_int_l = ( aa * u(kk,jj,ii) + &
1797	bb * u(kk,jj,ii+1) + &
1798	cc * u(kk,jj+1,ii) + &
1799	dd * u(kk,jj+1,ii+1) &
1800	) / gg
1801
1802	u_int_u = ( aa * u(kk+1,jj,ii) + &
1803	bb * u(kk+1,jj,ii+1) + &
1804	cc * u(kk+1,jj+1,ii) + &
1805	dd * u(kk+1,jj+1,ii+1) &
1806	) / gg
1807
1808	u_int_1_l(inot,ring,rseg) = u_int_l + &
1809	( rbz(ring,rseg) - zu(kk) ) / dz(1) * &
1810	( u_int_u - u_int_l )
1811
1812	ELSE
1813	u_int_1_l(inot,ring,rseg) = 0.0_wp
1814	ENDIF
1815	ELSE
1816	u_int_1_l(inot,ring,rseg) = 0.0_wp
1817	ENDIF
1818
1819
1820	!
1821	!-- Interpolation of the v-component:
1822	ii = ( rbx(ring,rseg) - 0.5_wp * dx ) * ddx
1823	jj = rby(ring,rseg) * ddy
1824	kk = ( rbz(ring,rseg) + 0.5_wp * dz(1) ) / dz(1)
1825	!
1826	!-- Interpolate only if all required information is available on
1827	!-- the current PE:
1828	IF ( ( ii >= nxl ) .AND. ( ii <= nxr ) ) THEN
1829	IF ( ( jj >= nys ) .AND. ( jj <= nyn ) ) THEN
1830
1831	aa = ( ( ii + 1 + 0.5_wp ) * dx - rbx(ring,rseg) ) * &
1832	( ( jj + 1 ) * dy - rby(ring,rseg) )
1833	bb = ( rbx(ring,rseg) - ( ii + 0.5_wp ) * dx ) * &
1834	( ( jj + 1 ) * dy - rby(ring,rseg) )
1835	cc = ( ( ii + 1 + 0.5_wp ) * dx - rbx(ring,rseg) ) * &
1836	( rby(ring,rseg) - jj * dy )
1837	dd = ( rbx(ring,rseg) - ( ii + 0.5_wp ) * dx ) * &
1838	( rby(ring,rseg) - jj * dy )
1839	gg = dx * dy
1840
1841	v_int_l = ( aa * v(kk,jj,ii) + &
1842	bb * v(kk,jj,ii+1) + &
1843	cc * v(kk,jj+1,ii) + &
1844	dd * v(kk,jj+1,ii+1) &
1845	) / gg
1846
1847	v_int_u = ( aa * v(kk+1,jj,ii) + &
1848	bb * v(kk+1,jj,ii+1) + &
1849	cc * v(kk+1,jj+1,ii) + &
1850	dd * v(kk+1,jj+1,ii+1) &
1851	) / gg
1852
1853	v_int_1_l(inot,ring,rseg) = v_int_l + &
1854	( rbz(ring,rseg) - zu(kk) ) / dz(1) * &
1855	( v_int_u - v_int_l )
1856
1857	ELSE
1858	v_int_1_l(inot,ring,rseg) = 0.0_wp
1859	ENDIF
1860	ELSE
1861	v_int_1_l(inot,ring,rseg) = 0.0_wp
1862	ENDIF
1863
1864
1865	!
1866	!-- Interpolation of the w-component:
1867	ii = ( rbx(ring,rseg) - 0.5_wp * dx ) * ddx
1868	jj = ( rby(ring,rseg) - 0.5_wp * dy ) * ddy
1869	kk = rbz(ring,rseg) / dz(1)
1870	!
1871	!-- Interpolate only if all required information is available on
1872	!-- the current PE:
1873	IF ( ( ii >= nxl ) .AND. ( ii <= nxr ) ) THEN
1874	IF ( ( jj >= nys ) .AND. ( jj <= nyn ) ) THEN
1875
1876	aa = ( ( ii + 1 + 0.5_wp ) * dx - rbx(ring,rseg) ) * &
1877	( ( jj + 1 + 0.5_wp ) * dy - rby(ring,rseg) )
1878	bb = ( rbx(ring,rseg) - ( ii + 0.5_wp ) * dx ) * &
1879	( ( jj + 1 + 0.5_wp ) * dy - rby(ring,rseg) )
1880	cc = ( ( ii + 1 + 0.5_wp ) * dx - rbx(ring,rseg) ) * &
1881	( rby(ring,rseg) - ( jj + 0.5_wp ) * dy )
1882	dd = ( rbx(ring,rseg) - ( ii + 0.5_wp ) * dx ) * &
1883	( rby(ring,rseg) - ( jj + 0.5_wp ) * dy )
1884	gg = dx * dy
1885
1886	w_int_l = ( aa * w(kk,jj,ii) + &
1887	bb * w(kk,jj,ii+1) + &
1888	cc * w(kk,jj+1,ii) + &
1889	dd * w(kk,jj+1,ii+1) &
1890	) / gg
1891
1892	w_int_u = ( aa * w(kk+1,jj,ii) + &
1893	bb * w(kk+1,jj,ii+1) + &
1894	cc * w(kk+1,jj+1,ii) + &
1895	dd * w(kk+1,jj+1,ii+1) &
1896	) / gg
1897
1898	w_int_1_l(inot,ring,rseg) = w_int_l + &
1899	( rbz(ring,rseg) - zw(kk) ) / dz(1) * &
1900	( w_int_u - w_int_l )
1901	ELSE
1902	w_int_1_l(inot,ring,rseg) = 0.0_wp
1903	ENDIF
1904	ELSE
1905	w_int_1_l(inot,ring,rseg) = 0.0_wp
1906	ENDIF
1907
1908	ENDDO
1909	ENDDO
1910
1911	ENDDO
1912
1913	!
1914	!-- Exchange between PEs (information required on each PE):
1915	#if defined( __parallel )
1916	CALL MPI_ALLREDUCE( u_int_1_l, u_int, nturbines * MAXVAL(nrings) * &
1917	MAXVAL(nsegs), MPI_REAL, MPI_SUM, comm2d, ierr )
1918	CALL MPI_ALLREDUCE( v_int_1_l, v_int, nturbines * MAXVAL(nrings) * &
1919	MAXVAL(nsegs), MPI_REAL, MPI_SUM, comm2d, ierr )
1920	CALL MPI_ALLREDUCE( w_int_1_l, w_int, nturbines * MAXVAL(nrings) * &
1921	MAXVAL(nsegs), MPI_REAL, MPI_SUM, comm2d, ierr )
1922	#else
1923	u_int = u_int_1_l
1924	v_int = v_int_1_l
1925	w_int = w_int_1_l
1926	#endif
1927
1928
1929	!
1930	!-- Loop over number of turbines:
1931
1932	DO inot = 1, nturbines
1933	pit_loop: DO
1934
1935	IF ( pitch_sw ) THEN
1936	torque_total(inot) = 0.0_wp
1937	thrust_rotor(inot) = 0.0_wp
1938	pitch_add(inot) = pitch_add(inot) + 0.25_wp
1939	! IF ( myid == 0 ) PRINT*, 'Pitch', inot, pitch_add(inot)
1940	ELSE
1941	cos_yaw = COS(phi_yaw(inot))
1942	sin_yaw = SIN(phi_yaw(inot))
1943	IF ( pitch_control ) THEN
1944	pitch_add(inot) = MAX(pitch_add_old(inot) - pitch_rate * &
1945	dt_3d , 0.0_wp )
1946	ENDIF
1947	ENDIF
1948
1949	!
1950	!-- Loop over rings of each turbine:
1951	DO ring = 1, nrings(inot)
1952	!
1953	!-- Determine distance between each ring (center) and the hub:
1954	cur_r = (ring - 0.5_wp) * delta_r(inot)
1955	!
1956	!-- Loop over segments of each ring of each turbine:
1957	DO rseg = 1, nsegs(ring,inot)
1958	!
1959	!-- Determine angle of ring segment towards zero degree angle of
1960	!-- rotor system (at zero degree rotor direction vectors aligned
1961	!-- with y-axis):
1962	phi_rotor = rseg * 2.0_wp * pi / nsegs(ring,inot)
1963	cos_rot = COS(phi_rotor)
1964	sin_rot = SIN(phi_rotor)
1965	!
1966	!-- Now the direction vectors can be determined with respect to
1967	!-- the yaw and tilt angle:
1968	re(1) = cos_rot * sin_yaw
1969	re(2) = cos_rot * cos_yaw
1970	re(3) = sin_rot
1971
1972	! The current unit vector in azimuthal direction:
1973	rea(1) = - sin_rot * sin_yaw
1974	rea(2) = - sin_rot * cos_yaw
1975	rea(3) = cos_rot
1976
1977	!
1978	!-- To respect the yawing angle for the calculations of
1979	!-- velocities and forces the unit vectors perpendicular to the
1980	!-- rotor area in direction of the positive yaw angle are defined:
1981	ren(1) = cos_yaw
1982	ren(2) = - sin_yaw
1983	ren(3) = 0.0_wp
1984	!
1985	!-- Multiplication with the coordinate transformation matrix
1986	!-- gives the final unit vector with consideration of the rotor
1987	!-- tilt:
1988	rote = MATMUL( rot_coord_trans(inot,:,:), re )
1989	rota = MATMUL( rot_coord_trans(inot,:,:), rea )
1990	rotn = MATMUL( rot_coord_trans(inot,:,:), ren )
1991	!
1992	!-- Coordinates of the single segments (center points):
1993	rbx(ring,rseg) = rcx(inot) + cur_r * rote(1)
1994
1995	rby(ring,rseg) = rcy(inot) + cur_r * rote(2)
1996
1997	rbz(ring,rseg) = rcz(inot) + cur_r * rote(3)
1998
1999	!
2000	!-- !-----------------------------------------------------------!
2001	!-- !-- Calculation of various angles and relative velocities --!
2002	!-- !-----------------------------------------------------------!
2003	!
2004	!-- In the following the 3D-velocity field is projected its
2005	!-- components perpendicular and parallel to the rotor area
2006	!-- The calculation of forces will be done in the rotor-
2007	!-- coordinates y' and z.
2008	!-- The yaw angle will be reintroduced when the force is applied
2009	!-- on the hydrodynamic equations
2010	!
2011	!-- Projection of the xy-velocities relative to the rotor area
2012	!
2013	!-- Velocity perpendicular to the rotor area:
2014	u_rot = u_int(inot,ring,rseg)*rotn(1) + &
2015	v_int(inot,ring,rseg)*rotn(2) + &
2016	w_int(inot,ring,rseg)*rotn(3)
2017	!
2018	!-- Projection of the 3D-velocity vector in the azimuthal
2019	!-- direction:
2020	vtheta(rseg) = rota(1) * u_int(inot,ring,rseg) + &
2021	rota(2) * v_int(inot,ring,rseg) + &
2022	rota(3) * w_int(inot,ring,rseg)
2023	!
2024	!-- Determination of the angle phi_rel between the rotor plane
2025	!-- and the direction of the flow relative to the rotor:
2026
2027	phi_rel(rseg) = ATAN( u_rot / &
2028	( omega_rot(inot) * cur_r - &
2029	vtheta(rseg) ) )
2030
2031	!
2032	!-- Interpolation of the local pitch angle from tabulated values
2033	!-- to the current radial position:
2034
2035	lct=minloc(ABS(cur_r-lrd))
2036	rad_d=cur_r-lrd(lct)
2037
2038	IF (cur_r == 0.0_wp) THEN
2039	alpha_attack(rseg) = 0.0_wp
2040	ELSE IF (cur_r >= lrd(size(ard))) THEN
2041	alpha_attack(rseg) = ( ard(size(ard)) + &
2042	ard(size(ard)-1) ) / 2.0_wp
2043	ELSE
2044	alpha_attack(rseg) = ( ard(lct(1)) * &
2045	( ( lrd(lct(1)+1) - cur_r ) / &
2046	( lrd(lct(1)+1) - lrd(lct(1)) ) &
2047	) ) + ( ard(lct(1)+1) * &
2048	( ( cur_r - lrd(lct(1)) ) / &
2049	( lrd(lct(1)+1) - lrd(lct(1)) ) ) )
2050	ENDIF
2051
2052	!
2053	!-- In Fortran radian instead of degree is used as unit for all
2054	!-- angles. Therefore, a transformation from angles given in
2055	!-- degree to angles given in radian is necessary here:
2056	alpha_attack(rseg) = alpha_attack(rseg) * &
2057	( (2.0_wp*pi) / 360.0_wp )
2058	!
2059	!-- Substraction of the local pitch angle to obtain the local
2060	!-- angle of attack:
2061	alpha_attack(rseg) = phi_rel(rseg) - alpha_attack(rseg)
2062	!
2063	!-- Preliminary transformation back from angles given in radian
2064	!-- to angles given in degree:
2065	alpha_attack(rseg) = alpha_attack(rseg) * &
2066	( 360.0_wp / (2.0_wp*pi) )
2067	!
2068	!-- Correct with collective pitch angle:
2069	alpha_attack = alpha_attack - pitch_add(inot)
2070
2071	!
2072	!-- Determination of the magnitude of the flow velocity relative
2073	!-- to the rotor:
2074	vrel(rseg) = SQRT( u_rot**2 + &
2075	( omega_rot(inot) * cur_r - &
2076	vtheta(rseg) )**2 )
2077
2078	!
2079	!-- !-----------------------------------------------------------!
2080	!-- !-- Interpolation of chord as well as lift and drag --!
2081	!-- !-- coefficients from tabulated values --!
2082	!-- !-----------------------------------------------------------!
2083
2084	!
2085	!-- Interpolation of the chord_length from tabulated values to
2086	!-- the current radial position:
2087
2088	IF (cur_r == 0.0_wp) THEN
2089	chord(rseg) = 0.0_wp
2090	ELSE IF (cur_r >= lrd(size(crd))) THEN
2091	chord(rseg) = (crd(size(crd)) + ard(size(crd)-1)) / 2.0_wp
2092	ELSE
2093	chord(rseg) = ( crd(lct(1)) * &
2094	( ( lrd(lct(1)+1) - cur_r ) / &
2095	( lrd(lct(1)+1) - lrd(lct(1)) ) ) ) + &
2096	( crd(lct(1)+1) * &
2097	( ( cur_r-lrd(lct(1)) ) / &
2098	( lrd(lct(1)+1) - lrd(lct(1)) ) ) )
2099	ENDIF
2100
2101	!
2102	!-- Determine index of current angle of attack, needed for
2103	!-- finding the appropriate interpolated values of the lift and
2104	!-- drag coefficients (-180.0 degrees = 1, +180.0 degrees = 3601,
2105	!-- so one index every 0.1 degrees):
2106	iialpha = CEILING( ( alpha_attack(rseg) + 180.0_wp ) &
2107	* ( 1.0_wp / accu_cl_cd_tab ) ) + 1.0_wp
2108	!
2109	!-- Determine index of current radial position, needed for
2110	!-- finding the appropriate interpolated values of the lift and
2111	!-- drag coefficients (one index every 0.1 m):
2112	iir = CEILING( cur_r * 10.0_wp )
2113	!
2114	!-- Read in interpolated values of the lift and drag coefficients
2115	!-- for the current radial position and angle of attack:
2116	turb_cl(rseg) = turb_cl_tab(iialpha,iir)
2117	turb_cd(rseg) = turb_cd_tab(iialpha,iir)
2118
2119	!
2120	!-- Final transformation back from angles given in degree to
2121	!-- angles given in radian:
2122	alpha_attack(rseg) = alpha_attack(rseg) * &
2123	( (2.0_wp*pi) / 360.0_wp )
2124
2125	IF ( tl_cor ) THEN
2126
2127	!-- Tip loss correction following Schito
2128	!-- Schito applies the tip loss correction only to the lift force
2129	!-- Therefore, the tip loss correction is only applied to the lift
2130	!-- coefficient and not to the drag coefficient in our case
2131	!--
2132	tl_factor = ( 2.0 / pi ) * &
2133	ACOS( EXP( -1.0 * ( 3.0 * ( rr(inot) - cur_r ) / &
2134	( 2.0 * cur_r * abs( sin( phi_rel(rseg) ) ) ) ) ) )
2135
2136	turb_cl(rseg) = tl_factor * turb_cl(rseg)
2137
2138	ENDIF
2139	!
2140	!-- !-----------------------------------------------------!
2141	!-- !-- Calculation of the forces --!
2142	!-- !-----------------------------------------------------!
2143
2144	!
2145	!-- Calculate the pre_factor for the thrust and torque forces:
2146
2147	pre_factor = 0.5_wp * (vrel(rseg)*2) 3.0_wp * &
2148	chord(rseg) * delta_r(inot) / nsegs(ring,inot)
2149
2150	!
2151	!-- Calculate the thrust force (x-component of the total force)
2152	!-- for each ring segment:
2153	thrust_seg(rseg) = pre_factor * &
2154	( turb_cl(rseg) * COS(phi_rel(rseg)) + &
2155	turb_cd(rseg) * SIN(phi_rel(rseg)) )
2156
2157	!
2158	!-- Determination of the second of the additional forces acting
2159	!-- on the flow in the azimuthal direction: force vector as basis
2160	!-- for torque (torque itself would be the vector product of the
2161	!-- radius vector and the force vector):
2162	torque_seg = pre_factor * &
2163	( turb_cl(rseg) * SIN(phi_rel(rseg)) - &
2164	turb_cd(rseg) * COS(phi_rel(rseg)) )
2165	!
2166	!-- Decomposition of the force vector into two parts:
2167	!-- One acting along the y-direction and one acting along the
2168	!-- z-direction of the rotor coordinate system:
2169
2170	torque_seg_y(rseg) = -torque_seg * sin_rot
2171	torque_seg_z(rseg) = torque_seg * cos_rot
2172
2173	!
2174	!-- Add the segment thrust to the thrust of the whole rotor
2175	thrust_rotor(inot) = thrust_rotor(inot) + &
2176	thrust_seg(rseg)
2177
2178
2179	torque_total(inot) = torque_total(inot) + (torque_seg * cur_r)
2180
2181	ENDDO !-- end of loop over ring segments
2182
2183	!
2184	!-- Restore the forces into arrays containing all the segments of
2185	!-- each ring:
2186	thrust_ring(ring,:) = thrust_seg(:)
2187	torque_ring_y(ring,:) = torque_seg_y(:)
2188	torque_ring_z(ring,:) = torque_seg_z(:)
2189
2190
2191	ENDDO !-- end of loop over rings
2192
2193
2194	CALL cpu_log( log_point_s(62), 'wtm_controller', 'start' )
2195
2196
2197	IF ( speed_control ) THEN
2198	!
2199	!-- Calculation of the current generator speed for rotor speed control
2200
2201	!
2202	!-- The acceleration of the rotor speed is calculated from
2203	!-- the force balance of the accelerating torque
2204	!-- and the torque of the rotating rotor and generator
2205	om_rate = ( torque_total(inot) * air_dens * gear_eff - &
2206	gear_ratio * torque_gen_old(inot) ) / &
2207	( inertia_rot + &
2208	gear_ratio * gear_ratio * inertia_gen ) * dt_3d
2209
2210	!
2211	!-- The generator speed is given by the product of gear gear_ratio
2212	!-- and rotor speed
2213	omega_gen(inot) = gear_ratio * ( omega_rot(inot) + om_rate )
2214
2215	ENDIF
2216
2217	IF ( pitch_control ) THEN
2218
2219	!
2220	!-- If the current generator speed is above rated, the pitch is not
2221	!-- saturated and the change from the last time step is within the
2222	!-- maximum pitch rate, then the pitch loop is repeated with a pitch
2223	!-- gain
2224	IF ( ( omega_gen(inot) > rated_genspeed ) .AND. &
2225	( pitch_add(inot) < 25.0_wp ) .AND. &
2226	( pitch_add(inot) < pitch_add_old(inot) + &
2227	pitch_rate * dt_3d ) ) THEN
2228	pitch_sw = .TRUE.
2229	!
2230	!-- Go back to beginning of pit_loop
2231	CYCLE pit_loop
2232	ENDIF
2233
2234	!
2235	!-- The current pitch is saved for the next time step
2236	pitch_add_old(inot) = pitch_add(inot)
2237	pitch_sw = .FALSE.
2238	ENDIF
2239	EXIT pit_loop
2240	ENDDO pit_loop ! Recursive pitch control loop
2241
2242
2243	!
2244	!-- Call the rotor speed controller
2245
2246	IF ( speed_control ) THEN
2247	!
2248	!-- Find processor at i_hub, j_hub
2249	IF ( ( nxl <= i_hub(inot) ) .AND. ( nxr >= i_hub(inot) ) ) &
2250	THEN
2251	IF ( ( nys <= j_hub(inot) ) .AND. ( nyn >= j_hub(inot) ) )&
2252	THEN
2253	CALL wtm_speed_control( inot )
2254	ENDIF
2255	ENDIF
2256
2257	ENDIF
2258
2259
2260	CALL cpu_log( log_point_s(62), 'wtm_controller', 'stop' )
2261
2262	CALL cpu_log( log_point_s(63), 'wtm_smearing', 'start' )
2263
2264
2265	!-- !-----------------------------------------------------------------!
2266	!-- !-- Regularization kernel --!
2267	!-- !-- Smearing of the forces and interpolation to cartesian grid --!
2268	!-- !-----------------------------------------------------------------!
2269	!
2270	!-- The aerodynamic blade forces need to be distributed smoothly on
2271	!-- several mesh points in order to avoid singular behaviour
2272	!
2273	!-- Summation over sum of weighted forces. The weighting factor
2274	!-- (calculated in user_init) includes information on the distance
2275	!-- between the center of the grid cell and the rotor segment under
2276	!-- consideration
2277	!
2278	!-- To save computing time, apply smearing only for the relevant part
2279	!-- of the model domain:
2280	!
2281	!--
2282	!-- Calculation of the boundaries:
2283	i_smear(inot) = CEILING( ( rr(inot) * ABS( roty(inot,1) ) + &
2284	eps_min ) / dx )
2285	j_smear(inot) = CEILING( ( rr(inot) * ABS( roty(inot,2) ) + &
2286	eps_min ) / dy )
2287
2288	DO i = MAX( nxl, i_hub(inot) - i_smear(inot) ), &
2289	MIN( nxr, i_hub(inot) + i_smear(inot) )
2290	DO j = MAX( nys, j_hub(inot) - j_smear(inot) ), &
2291	MIN( nyn, j_hub(inot) + j_smear(inot) )
2292	! DO k = MAX( nzb_u_inner(j,i)+1, k_hub(inot) - k_smear(inot) ), &
2293	! k_hub(inot) + k_smear(inot)
2294	DO k = nzb+1, k_hub(inot) + k_smear(inot)
2295	DO ring = 1, nrings(inot)
2296	DO rseg = 1, nsegs(ring,inot)
2297	!
2298	!-- Predetermine flag to mask topography
2299	flag = MERGE( 1.0_wp, 0.0_wp, BTEST( wall_flags_0(k,j,i), 1 ) )
2300
2301	!
2302	!-- Determine the square of the distance between the
2303	!-- current grid point and each rotor area segment:
2304	dist_u_3d = ( i * dx - rbx(ring,rseg) )**2 + &
2305	( j * dy + 0.5_wp * dy - rby(ring,rseg) )**2 + &
2306	( k * dz(1) - 0.5_wp * dz(1) - rbz(ring,rseg) )**2
2307	dist_v_3d = ( i * dx + 0.5_wp * dx - rbx(ring,rseg) )**2 + &
2308	( j * dy - rby(ring,rseg) )**2 + &
2309	( k * dz(1) - 0.5_wp * dz(1) - rbz(ring,rseg) )**2
2310	dist_w_3d = ( i * dx + 0.5_wp * dx - rbx(ring,rseg) )**2 + &
2311	( j * dy + 0.5_wp * dy - rby(ring,rseg) )**2 + &
2312	( k * dz(1) - rbz(ring,rseg) )**2
2313
2314	!
2315	!-- 3D-smearing of the forces with a polynomial function
2316	!-- (much faster than the old Gaussian function), using
2317	!-- some parameters that have been calculated in user_init.
2318	!-- The function is only similar to Gaussian function for
2319	!-- squared distances <= eps_min2:
2320	IF ( dist_u_3d <= eps_min2 ) THEN
2321	thrust(k,j,i) = thrust(k,j,i) + &
2322	thrust_ring(ring,rseg) * &
2323	( ( pol_a * dist_u_3d - pol_b ) * &
2324	dist_u_3d + 1.0_wp ) * eps_factor *&
2325	flag
2326	ENDIF
2327	IF ( dist_v_3d <= eps_min2 ) THEN
2328	torque_y(k,j,i) = torque_y(k,j,i) + &
2329	torque_ring_y(ring,rseg) * &
2330	( ( pol_a * dist_v_3d - pol_b ) * &
2331	dist_v_3d + 1.0_wp ) * eps_factor * &
2332	flag
2333	ENDIF
2334	IF ( dist_w_3d <= eps_min2 ) THEN
2335	torque_z(k,j,i) = torque_z(k,j,i) + &
2336	torque_ring_z(ring,rseg) * &
2337	( ( pol_a * dist_w_3d - pol_b ) * &
2338	dist_w_3d + 1.0_wp ) * eps_factor * &
2339	flag
2340	ENDIF
2341
2342	ENDDO ! End of loop over rseg
2343	ENDDO ! End of loop over ring
2344
2345	!
2346	!-- Rotation of force components:
2347	rot_tend_x(k,j,i) = rot_tend_x(k,j,i) + ( &
2348	thrust(k,j,i)*rotx(inot,1) + &
2349	torque_y(k,j,i)*roty(inot,1) + &
2350	torque_z(k,j,i)*rotz(inot,1) &
2351	) * flag
2352
2353	rot_tend_y(k,j,i) = rot_tend_y(k,j,i) + ( &
2354	thrust(k,j,i)*rotx(inot,2) + &
2355	torque_y(k,j,i)*roty(inot,2) + &
2356	torque_z(k,j,i)*rotz(inot,2) &
2357	) * flag
2358
2359	rot_tend_z(k,j,i) = rot_tend_z(k,j,i) + ( &
2360	thrust(k,j,i)*rotx(inot,3) + &
2361	torque_y(k,j,i)*roty(inot,3) + &
2362	torque_z(k,j,i)*rotz(inot,3) &
2363	) * flag
2364
2365	ENDDO ! End of loop over k
2366	ENDDO ! End of loop over j
2367	ENDDO ! End of loop over i
2368
2369	CALL cpu_log( log_point_s(63), 'wtm_smearing', 'stop' )
2370
2371	ENDDO !-- end of loop over turbines
2372
2373
2374	IF ( yaw_control ) THEN
2375	!
2376	!-- Allocate arrays for yaw control at first call
2377	!-- Can't be allocated before dt_3d is set
2378	IF ( start_up ) THEN
2379	WDLON = NINT( 30.0_wp / dt_3d ) ! 30s running mean array
2380	ALLOCATE( wd30(1:nturbines,1:WDLON) )
2381	wd30 = 999.0_wp ! Set to dummy value
2382	ALLOCATE( wd30_l(1:WDLON) )
2383
2384	WDSHO = NINT( 2.0_wp / dt_3d ) ! 2s running mean array
2385	ALLOCATE( wd2(1:nturbines,1:WDSHO) )
2386	wd2 = 999.0_wp ! Set to dummy value
2387	ALLOCATE( wd2_l(1:WDSHO) )
2388	start_up = .FALSE.
2389	ENDIF
2390
2391	!
2392	!-- Calculate the inflow wind speed
2393	!--
2394	!-- Loop over number of turbines:
2395	DO inot = 1, nturbines
2396	!
2397	!-- Find processor at i_hub, j_hub
2398	IF ( ( nxl <= i_hub(inot) ) .AND. ( nxr >= i_hub(inot) ) ) &
2399	THEN
2400	IF ( ( nys <= j_hub(inot) ) .AND. ( nyn >= j_hub(inot) ) )&
2401	THEN
2402
2403	u_inflow_l(inot) = u(k_hub(inot),j_hub(inot),i_hub(inot))
2404
2405	wdir_l(inot) = -1.0_wp * ATAN2( &
2406	0.5_wp * ( v(k_hub(inot),j_hub(inot),i_hub(inot)+1) + &
2407	v(k_hub(inot),j_hub(inot),i_hub(inot)) ) , &
2408	0.5_wp * ( u(k_hub(inot),j_hub(inot)+1,i_hub(inot)) + &
2409	u(k_hub(inot),j_hub(inot),i_hub(inot)) ) )
2410
2411	CALL wtm_yawcontrol( inot )
2412
2413	phi_yaw_l(inot) = phi_yaw(inot)
2414
2415	ENDIF
2416	ENDIF
2417
2418	ENDDO !-- end of loop over turbines
2419
2420	!
2421	!-- Transfer of information to the other cpus
2422	#if defined( __parallel )
2423	CALL MPI_ALLREDUCE( u_inflow_l, u_inflow, nturbines, MPI_REAL, &
2424	MPI_SUM, comm2d, ierr )
2425	CALL MPI_ALLREDUCE( wdir_l, wdir, nturbines, MPI_REAL, MPI_SUM, &
2426	comm2d, ierr )
2427	CALL MPI_ALLREDUCE( phi_yaw_l, phi_yaw, nturbines, MPI_REAL, &
2428	MPI_SUM, comm2d, ierr )
2429	#else
2430	u_inflow = u_inflow_l
2431	wdir = wdir_l
2432	phi_yaw = phi_yaw_l
2433
2434
2435	#endif
2436	DO inot = 1, nturbines
2437	!
2438	!-- Update rotor orientation
2439	CALL wtm_rotate_rotor( inot )
2440
2441	ENDDO ! End of loop over turbines
2442
2443	ENDIF ! end of yaw control
2444
2445	IF ( speed_control ) THEN
2446	!
2447	!-- Transfer of information to the other cpus
2448	! CALL MPI_ALLREDUCE( omega_gen, omega_gen_old, nturbines, &
2449	! MPI_REAL,MPI_SUM, comm2d, ierr )
2450	#if defined( __parallel )
2451	CALL MPI_ALLREDUCE( torque_gen, torque_gen_old, nturbines, &
2452	MPI_REAL, MPI_SUM, comm2d, ierr )
2453	CALL MPI_ALLREDUCE( omega_rot_l, omega_rot, nturbines, &
2454	MPI_REAL, MPI_SUM, comm2d, ierr )
2455	CALL MPI_ALLREDUCE( omega_gen_f, omega_gen_f_old, nturbines, &
2456	MPI_REAL, MPI_SUM, comm2d, ierr )
2457	#else
2458	torque_gen_old = torque_gen
2459	omega_rot = omega_rot_l
2460	omega_gen_f_old = omega_gen_f
2461	#endif
2462
2463	ENDIF
2464
2465	DO inot = 1, nturbines
2466
2467	IF ( myid == 0 ) THEN
2468	IF ( openfile_turb_mod(400+inot)%opened ) THEN
2469	WRITE ( 400+inot, 106 ) simulated_time, omega_rot(inot), &
2470	omega_gen(inot), torque_gen_old(inot), &
2471	torque_total(inot), pitch_add(inot), &
2472	torque_gen_old(inot)omega_gen(inot)gen_eff, &
2473	torque_total(inot)omega_rot(inot)air_dens, &
2474	thrust_rotor(inot), &
2475	wdir(inot)*180.0_wp/pi, &
2476	(phi_yaw(inot))*180.0_wp/pi
2477
2478	ELSE
2479
2480	WRITE ( turbine_id,'(A2,I2.2)') '_T', inot
2481	OPEN ( 400+inot, FILE=( 'WTM_OUTPUT_DATA' // &
2482	TRIM( coupling_char ) // &
2483	turbine_id ), FORM='FORMATTED' )
2484	WRITE ( 400+inot, 105 ) inot
2485	WRITE ( 400+inot, 106 ) simulated_time, omega_rot(inot), &
2486	omega_gen(inot), torque_gen_old(inot), &
2487	torque_total(inot), pitch_add(inot), &
2488	torque_gen_old(inot)omega_gen(inot)gen_eff, &
2489	torque_total(inot)omega_rot(inot)air_dens, &
2490	thrust_rotor(inot), &
2491	wdir(inot)*180.0_wp/pi, &
2492	(phi_yaw(inot))*180.0_wp/pi
2493	ENDIF
2494	ENDIF
2495
2496	!-- Set open flag
2497	openfile_turb_mod(400+inot)%opened = .TRUE.
2498	ENDDO !-- end of loop over turbines
2499
2500	ENDIF
2501
2502	CALL cpu_log( log_point_s(61), 'wtm_forces', 'stop' )
2503
2504	!
2505	!-- Formats
2506	105 FORMAT ('Turbine control data for turbine ',I2,1X,':'/ &
2507	&'----------------------------------------'/ &
2508	&' Time RSpeed GSpeed ', &
2509	'GenTorque AeroTorque Pitch Power(Gen) Power(Rot) ', &
2510	'RotThrust WDirection YawOrient')
2511
2512	106 FORMAT (F9.3,2X,F7.3,2X,F7.2,2X,F9.1,3X,F9.1,1X,F6.2,2X,F10.1,2X, &
2513	F10.1,1X,F9.1,2X,F7.2,1X,F7.2)
2514
2515
2516	END SUBROUTINE wtm_forces
2517
2518
2519	!------------------------------------------------------------------------------!
2520	! Description:
2521	! ------------
2522	!> Yaw controller for the wind turbine model
2523	!------------------------------------------------------------------------------!
2524	SUBROUTINE wtm_yawcontrol( inot )
2525
2526	USE kinds
2527
2528	IMPLICIT NONE
2529
2530	INTEGER(iwp) :: inot
2531	INTEGER(iwp) :: i_wd_30
2532	REAL(wp) :: missal
2533
2534	i_wd_30 = 0_iwp
2535
2536	!
2537	!-- The yaw controller computes a 30s running mean of the wind direction.
2538	!-- If the difference between turbine alignment and wind direction exceeds
2539	!-- 5Â°, the turbine is yawed. The mechanism stops as soon as the 2s-running
2540	!-- mean of the missalignment is smaller than 0.5Â°.
2541	!-- Attention: If the timestep during the simulation changes significantly
2542	!-- the lengths of the running means change and it does not correspond to
2543	!-- 30s/2s anymore.
2544	!-- ! Needs to be modified for these situations !
2545	!-- For wind from the east, the averaging of the wind direction could cause
2546	!-- problems and the yaw controller is probably flawed. -> Routine for
2547	!-- averaging needs to be improved!
2548	!
2549	!-- Check if turbine is not yawing
2550	IF ( .NOT. doyaw(inot) ) THEN
2551	!
2552	!-- Write current wind direction into array
2553	wd30_l = wd30(inot,:)
2554	wd30_l = CSHIFT( wd30_l, SHIFT=-1 )
2555	wd30_l(1) = wdir(inot)
2556	!
2557	!-- Check if array is full ( no more dummies )
2558	IF ( .NOT. ANY( wd30_l == 999.) ) THEN
2559
2560	missal = SUM( wd30_l ) / SIZE( wd30_l ) - phi_yaw(inot)
2561	!
2562	!-- Check if turbine is missaligned by more than max_miss
2563	IF ( ABS( missal ) > max_miss ) THEN
2564	!
2565	!-- Check in which direction to yaw
2566	yawdir(inot) = SIGN( 1.0_wp, missal )
2567	!
2568	!-- Start yawing of turbine
2569	phi_yaw(inot) = phi_yaw(inot) + yawdir(inot) * yaw_speed * dt_3d
2570	doyaw(inot) = .TRUE.
2571	wd30_l = 999. ! fill with dummies again
2572	ENDIF
2573	ENDIF
2574
2575	wd30(inot,:) = wd30_l
2576
2577	!
2578	!-- If turbine is already yawing:
2579	!-- Initialize 2 s running mean and yaw until the missalignment is smaller
2580	!-- than min_miss
2581
2582	ELSE
2583	!
2584	!-- Initialize 2 s running mean
2585	wd2_l = wd2(inot,:)
2586	wd2_l = CSHIFT( wd2_l, SHIFT = -1 )
2587	wd2_l(1) = wdir(inot)
2588	!
2589	!-- Check if array is full ( no more dummies )
2590	IF ( .NOT. ANY( wd2_l == 999.0_wp ) ) THEN
2591	!
2592	!-- Calculate missalignment of turbine
2593	missal = SUM( wd2_l - phi_yaw(inot) ) / SIZE( wd2_l )
2594	!
2595	!-- Check if missalignment is still larger than 0.5 degree and if the
2596	!-- yaw direction is still right
2597	IF ( ( ABS( missal ) > min_miss ) .AND. &
2598	( yawdir(inot) == SIGN( 1.0_wp, missal ) ) ) THEN
2599	!
2600	!-- Continue yawing
2601	phi_yaw(inot) = phi_yaw(inot) + yawdir(inot) * yaw_speed * dt_3d
2602	ELSE
2603	!
2604	!-- Stop yawing
2605	doyaw(inot) = .FALSE.
2606	wd2_l = 999.0_wp ! fill with dummies again
2607	ENDIF
2608	ELSE
2609	!
2610	!-- Continue yawing
2611	phi_yaw(inot) = phi_yaw(inot) + yawdir(inot) * yaw_speed * dt_3d
2612	ENDIF
2613
2614	wd2(inot,:) = wd2_l
2615
2616	ENDIF
2617
2618	END SUBROUTINE wtm_yawcontrol
2619
2620
2621	!------------------------------------------------------------------------------!
2622	! Description:
2623	! ------------
2624	!> Initialization of the speed control
2625	!------------------------------------------------------------------------------!
2626	SUBROUTINE wtm_init_speed_control
2627
2628
2629	IMPLICIT NONE
2630
2631	!
2632	!-- If speed control is set, remaining variables and control_parameters for
2633	!-- the control algorithm are calculated
2634	!
2635	!-- Calculate slope constant for region 15
2636	slope15 = ( slope2 * min_reg2 * min_reg2 ) / ( min_reg2 - min_reg15 )
2637	!
2638	!-- Calculate upper limit of slipage region
2639	vs_sysp = rated_genspeed / 1.1_wp
2640	!
2641	!-- Calculate slope of slipage region
2642	slope25 = ( rated_power / rated_genspeed ) / &
2643	( rated_genspeed - vs_sysp )
2644	!
2645	!-- Calculate lower limit of slipage region
2646	min_reg25 = ( slope25 - SQRT( slope25 * ( slope25 - 4.0_wp * &
2647	slope2 * vs_sysp ) ) ) / &
2648	( 2.0_wp * slope2 )
2649	!
2650	!-- Frequency for the simple low pass filter
2651	Fcorner = 0.25_wp
2652	!
2653	!-- At the first timestep the torque is set to its maximum to prevent
2654	!-- an overspeeding of the rotor
2655	IF ( TRIM( initializing_actions ) /= 'read_restart_data' ) THEN
2656	torque_gen_old(:) = max_torque_gen
2657	ENDIF
2658
2659	END SUBROUTINE wtm_init_speed_control
2660
2661
2662	!------------------------------------------------------------------------------!
2663	! Description:
2664	! ------------
2665	!> Simple controller for the regulation of the rotor speed
2666	!------------------------------------------------------------------------------!
2667	SUBROUTINE wtm_speed_control( inot )
2668
2669
2670	IMPLICIT NONE
2671
2672	INTEGER(iwp) :: inot
2673
2674
2675
2676	!
2677	!-- The controller is based on the fortran script from Jonkman
2678	!-- et al. 2009 "Definition of a 5 MW Reference Wind Turbine for
2679	!-- offshore system developement"
2680
2681	!
2682	!-- The generator speed is filtered by a low pass filter
2683	!-- for the control of the generator torque
2684	lp_coeff = EXP( -2.0_wp * 3.14_wp * dt_3d * Fcorner )
2685	omega_gen_f(inot) = ( 1.0_wp - lp_coeff ) * omega_gen(inot) + lp_coeff *&
2686	omega_gen_f_old(inot)
2687
2688	IF ( omega_gen_f(inot) <= min_reg15 ) THEN
2689	!
2690	!-- Region 1: Generator torque is set to zero to accelerate the rotor:
2691	torque_gen(inot) = 0
2692
2693	ELSEIF ( omega_gen_f(inot) <= min_reg2 ) THEN
2694	!
2695	!-- Region 1.5: Generator torque is increasing linearly with rotor speed:
2696	torque_gen(inot) = slope15 * ( omega_gen_f(inot) - min_reg15 )
2697
2698	ELSEIF ( omega_gen_f(inot) <= min_reg25 ) THEN
2699	!
2700	!-- Region 2: Generator torque is increased by the square of the generator
2701	!-- speed to keep the TSR optimal:
2702	torque_gen(inot) = slope2 * omega_gen_f(inot) * omega_gen_f(inot)
2703
2704	ELSEIF ( omega_gen_f(inot) < rated_genspeed ) THEN
2705	!
2706	!-- Region 2.5: Slipage region between 2 and 3:
2707	torque_gen(inot) = slope25 * ( omega_gen_f(inot) - vs_sysp )
2708
2709	ELSE
2710	!
2711	!-- Region 3: Generator torque is antiproportional to the rotor speed to
2712	!-- keep the power constant:
2713	torque_gen(inot) = rated_power / omega_gen_f(inot)
2714
2715	ENDIF
2716	!
2717	!-- Calculate torque rate and confine with a max
2718	trq_rate = ( torque_gen(inot) - torque_gen_old(inot) ) / dt_3d
2719	trq_rate = MIN( MAX( trq_rate, -1.0_wp * max_trq_rate ), max_trq_rate )
2720	!
2721	!-- Calculate new gen torque and confine with max torque
2722	torque_gen(inot) = torque_gen_old(inot) + trq_rate * dt_3d
2723	torque_gen(inot) = MIN( torque_gen(inot), max_torque_gen )
2724	!
2725	!-- Overwrite values for next timestep
2726	omega_rot_l(inot) = omega_gen(inot) / gear_ratio
2727
2728
2729	END SUBROUTINE wtm_speed_control
2730
2731
2732	!------------------------------------------------------------------------------!
2733	! Description:
2734	! ------------
2735	!> Application of the additional forces generated by the wind turbine on the
2736	!> flow components (tendency terms)
2737	!> Call for all grid points
2738	!------------------------------------------------------------------------------!
2739	SUBROUTINE wtm_tendencies( component )
2740
2741
2742	IMPLICIT NONE
2743
2744	INTEGER(iwp) :: component !< prognostic variable (u,v,w)
2745	INTEGER(iwp) :: i !< running index
2746	INTEGER(iwp) :: j !< running index
2747	INTEGER(iwp) :: k !< running index
2748
2749
2750	SELECT CASE ( component )
2751
2752	CASE ( 1 )
2753	!
2754	!-- Apply the x-component of the force to the u-component of the flow:
2755	IF ( simulated_time >= time_turbine_on ) THEN
2756	DO i = nxlg, nxrg
2757	DO j = nysg, nyng
2758	DO k = nzb+1, MAXVAL(k_hub) + MAXVAL(k_smear)
2759	!
2760	!-- Calculate the thrust generated by the nacelle and the tower
2761	tend_nac_x = 0.5_wp * nac_cd_surf(k,j,i) * &
2762	SIGN( u(k,j,i)**2 , u(k,j,i) )
2763	tend_tow_x = 0.5_wp * tow_cd_surf(k,j,i) * &
2764	SIGN( u(k,j,i)**2 , u(k,j,i) )
2765
2766	tend(k,j,i) = tend(k,j,i) + ( - rot_tend_x(k,j,i) &
2767	- tend_nac_x - tend_tow_x ) &
2768	* MERGE( 1.0_wp, 0.0_wp, &
2769	BTEST( wall_flags_0(k,j,i), 1 ) )
2770	ENDDO
2771	ENDDO
2772	ENDDO
2773	ENDIF
2774
2775	CASE ( 2 )
2776	!
2777	!-- Apply the y-component of the force to the v-component of the flow:
2778	IF ( simulated_time >= time_turbine_on ) THEN
2779	DO i = nxlg, nxrg
2780	DO j = nysg, nyng
2781	DO k = nzb+1, MAXVAL(k_hub) + MAXVAL(k_smear)
2782	tend_nac_y = 0.5_wp * nac_cd_surf(k,j,i) * &
2783	SIGN( v(k,j,i)**2 , v(k,j,i) )
2784	tend_tow_y = 0.5_wp * tow_cd_surf(k,j,i) * &
2785	SIGN( v(k,j,i)**2 , v(k,j,i) )
2786	tend(k,j,i) = tend(k,j,i) + ( - rot_tend_y(k,j,i) &
2787	- tend_nac_y - tend_tow_y ) &
2788	* MERGE( 1.0_wp, 0.0_wp, &
2789	BTEST( wall_flags_0(k,j,i), 2 ) )
2790	ENDDO
2791	ENDDO
2792	ENDDO
2793	ENDIF
2794
2795	CASE ( 3 )
2796	!
2797	!-- Apply the z-component of the force to the w-component of the flow:
2798	IF ( simulated_time >= time_turbine_on ) THEN
2799	DO i = nxlg, nxrg
2800	DO j = nysg, nyng
2801	DO k = nzb+1, MAXVAL(k_hub) + MAXVAL(k_smear)
2802	tend(k,j,i) = tend(k,j,i) - rot_tend_z(k,j,i) &
2803	* MERGE( 1.0_wp, 0.0_wp, &
2804	BTEST( wall_flags_0(k,j,i), 3 ) )
2805	ENDDO
2806	ENDDO
2807	ENDDO
2808	ENDIF
2809
2810
2811	CASE DEFAULT
2812
2813	WRITE( message_string, * ) 'unknown prognostic variable: ', component
2814	CALL message( 'wtm_tendencies', 'PA04??', 1, 2, 0, 6, 0 )
2815
2816	END SELECT
2817
2818
2819	END SUBROUTINE wtm_tendencies
2820
2821
2822	!------------------------------------------------------------------------------!
2823	! Description:
2824	! ------------
2825	!> Application of the additional forces generated by the wind turbine on the
2826	!> flow components (tendency terms)
2827	!> Call for grid point i,j
2828	!------------------------------------------------------------------------------!
2829	SUBROUTINE wtm_tendencies_ij( i, j, component )
2830
2831
2832	IMPLICIT NONE
2833
2834	INTEGER(iwp) :: component !< prognostic variable (u,v,w)
2835	INTEGER(iwp) :: i !< running index
2836	INTEGER(iwp) :: j !< running index
2837	INTEGER(iwp) :: k !< running index
2838
2839	SELECT CASE ( component )
2840
2841	CASE ( 1 )
2842	!
2843	!-- Apply the x-component of the force to the u-component of the flow:
2844	IF ( simulated_time >= time_turbine_on ) THEN
2845	DO k = nzb+1, MAXVAL(k_hub) + MAXVAL(k_smear)
2846	!
2847	!-- Calculate the thrust generated by the nacelle and the tower
2848	tend_nac_x = 0.5_wp * nac_cd_surf(k,j,i) * &
2849	SIGN( u(k,j,i)**2 , u(k,j,i) )
2850	tend_tow_x = 0.5_wp * tow_cd_surf(k,j,i) * &
2851	SIGN( u(k,j,i)**2 , u(k,j,i) )
2852	tend(k,j,i) = tend(k,j,i) + ( - rot_tend_x(k,j,i) &
2853	- tend_nac_x - tend_tow_x ) &
2854	* MERGE( 1.0_wp, 0.0_wp, &
2855	BTEST( wall_flags_0(k,j,i), 1 ) )
2856	ENDDO
2857	ENDIF
2858
2859	CASE ( 2 )
2860	!
2861	!-- Apply the y-component of the force to the v-component of the flow:
2862	IF ( simulated_time >= time_turbine_on ) THEN
2863	DO k = nzb+1, MAXVAL(k_hub) + MAXVAL(k_smear)
2864	tend_nac_y = 0.5_wp * nac_cd_surf(k,j,i) * &
2865	SIGN( v(k,j,i)**2 , v(k,j,i) )
2866	tend_tow_y = 0.5_wp * tow_cd_surf(k,j,i) * &
2867	SIGN( v(k,j,i)**2 , v(k,j,i) )
2868	tend(k,j,i) = tend(k,j,i) + ( - rot_tend_y(k,j,i) &
2869	- tend_nac_y - tend_tow_y ) &
2870	* MERGE( 1.0_wp, 0.0_wp, &
2871	BTEST( wall_flags_0(k,j,i), 2 ) )
2872	ENDDO
2873	ENDIF
2874
2875	CASE ( 3 )
2876	!
2877	!-- Apply the z-component of the force to the w-component of the flow:
2878	IF ( simulated_time >= time_turbine_on ) THEN
2879	DO k = nzb+1, MAXVAL(k_hub) + MAXVAL(k_smear)
2880	tend(k,j,i) = tend(k,j,i) - rot_tend_z(k,j,i) &
2881	* MERGE( 1.0_wp, 0.0_wp, &
2882	BTEST( wall_flags_0(k,j,i), 3 ) )
2883	ENDDO
2884	ENDIF
2885
2886
2887	CASE DEFAULT
2888
2889	WRITE( message_string, * ) 'unknown prognostic variable: ', component
2890	CALL message( 'wtm_tendencies', 'PA04??', 1, 2, 0, 6, 0 )
2891
2892	END SELECT
2893
2894
2895	END SUBROUTINE wtm_tendencies_ij
2896
2897	END MODULE wind_turbine_model_mod

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