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source: palm/trunk/SOURCE/wind_turbine_model_mod.f90 @ 1957

Last change on this file since 1957 was 1930, checked in by suehring, 8 years ago
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1	!> @file wind_turbine_model_mod.f90
2	!------------------------------------------------------------------------------!
3	! This file is part of PALM.
4	!
5	! PALM is free software: you can redistribute it and/or modify it under the terms
6	! of the GNU General Public License as published by the Free Software Foundation,
7	! either version 3 of the License, or (at your option) any later version.
8	!
9	! PALM is distributed in the hope that it will be useful, but WITHOUT ANY
10	! WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
11	! A PARTICULAR PURPOSE. See the GNU General Public License for more details.
12	!
13	! You should have received a copy of the GNU General Public License along with
14	! PALM. If not, see <http://www.gnu.org/licenses/>.
15	!
16	! Copyright 1997-2016 Leibniz Universitaet Hannover
17	!------------------------------------------------------------------------------!
18	!
19	! Current revisions:
20	! -----------------
21	!
22	!
23	! Former revisions:
24	! -----------------
25	! $Id: wind_turbine_model_mod.f90 1930 2016-06-09 16:32:12Z suehring $
26	!
27	! 1929 2016-06-09 16:25:25Z suehring
28	! Bugfix: added preprocessor directives for parallel and serial mode
29	!
30	! 1914 2016-05-26 14:44:07Z witha
31	! Initial revision
32	!
33	!
34	! Description:
35	! ------------
36	!> This module calculates the effect of wind turbines on the flow fields. The
37	!> initial version contains only the advanced actuator disk with rotation method
38	!> (ADM-R).
39	!> The wind turbines include the tower effect, can be yawed and tilted.
40	!> The wind turbine model includes controllers for rotational speed, pitch and
41	!> yaw.
42	!> Currently some specifications of the NREL 5 MW reference turbine
43	!> are hardcoded whereas most input data comes from separate files (currently
44	!> external, planned to be included as namelist which will be read in
45	!> automatically).
46	!>
47	!> @todo Revise code according to PALM Coding Standard
48	!> @todo Implement ADM and ALM turbine models
49	!> @todo Generate header information
50	!> @todo Implement further parameter checks and error messages
51	!> @todo Revise and add code documentation
52	!> @todo Output turbine parameters as timeseries
53	!> @todo Include additional output variables
54	!> @todo Revise smearing the forces for turbines in yaw
55	!> @todo Revise nacelle and tower parameterization
56	!> @todo Allow different turbine types in one simulation
57	!
58	!------------------------------------------------------------------------------!
59	MODULE wind_turbine_model_mod
60
61	USE arrays_3d, &
62	ONLY: dd2zu, tend, u, v, w, zu, zw
63
64	USE constants
65
66	USE control_parameters, &
67	ONLY: dt_3d, dz, message_string, simulated_time
68
69	USE cpulog, &
70	ONLY: cpu_log, log_point_s
71
72	USE grid_variables, &
73	ONLY: ddx, dx, ddy, dy
74
75	USE indices, &
76	ONLY: nbgp, nx, nxl, nxlg, nxr, nxrg, ny, nyn, nyng, nys, nysg, nz, &
77	nzb, nzb_u_inner, nzb_v_inner, nzb_w_inner, nzt
78
79	USE kinds
80
81	USE pegrid
82
83
84	IMPLICIT NONE
85
86	PRIVATE
87
88	LOGICAL :: wind_turbine=.FALSE. !< switch for use of wind turbine model
89
90	!
91	!-- Variables specified in the namelist wind_turbine_par
92
93	INTEGER(iwp) :: nairfoils = 8 !< number of airfoils of the used turbine model (for ADM-R and ALM)
94	INTEGER(iwp) :: nturbines = 1 !< number of turbines
95
96	LOGICAL :: pitch_control = .FALSE. !< switch for use of pitch controller
97	LOGICAL :: speed_control = .FALSE. !< switch for use of speed controller
98	LOGICAL :: yaw_control = .FALSE. !< switch for use of yaw controller
99
100	REAL(wp) :: segment_length = 1.0_wp !< length of the segments, the rotor area is divided into
101	!< (in tangential direction, as factor of MIN(dx,dy,dz))
102	REAL(wp) :: segment_width = 0.5_wp !< width of the segments, the rotor area is divided into
103	!< (in radial direction, as factor of MIN(dx,dy,dz))
104	REAL(wp) :: time_turbine_on = 0.0_wp !< time at which turbines are started
105	REAL(wp) :: tilt = 0.0_wp !< vertical tilt of the rotor [degree] ( positive = backwards )
106
107	REAL(wp), DIMENSION(1:100) :: dtow = 0.0_wp !< tower diameter [m]
108	REAL(wp), DIMENSION(1:100) :: omega_rot = 0.0_wp !< inital or constant rotor speed [rad/s]
109	REAL(wp), DIMENSION(1:100) :: phi_yaw = 0.0_wp !< yaw angle [degree] ( clockwise, 0 = facing west )
110	REAL(wp), DIMENSION(1:100) :: pitch_add = 0.0_wp !< constant pitch angle
111	REAL(wp), DIMENSION(1:100) :: rcx = 9999999.9_wp !< position of hub in x-direction
112	REAL(wp), DIMENSION(1:100) :: rcy = 9999999.9_wp !< position of hub in y-direction
113	REAL(wp), DIMENSION(1:100) :: rcz = 9999999.9_wp !< position of hub in z-direction
114	REAL(wp), DIMENSION(1:100) :: rnac = 0.0_wp !< nacelle diameter [m]
115	REAL(wp), DIMENSION(1:100) :: rr = 63.0_wp !< rotor radius [m]
116	REAL(wp), DIMENSION(1:100) :: turb_cd_nacelle = 0.85_wp !< drag coefficient for nacelle
117	REAL(wp), DIMENSION(1:100) :: turb_cd_tower = 1.2_wp !< drag coefficient for tower
118
119	!
120	!-- Variables specified in the namelist for speed controller
121	!-- Default values are from the NREL 5MW research turbine (Jonkman, 2008)
122
123	REAL(wp) :: rated_power = 5296610.0_wp !< rated turbine power [W]
124	REAL(wp) :: gear_ratio = 97.0_wp !< Gear ratio from rotor to generator
125	REAL(wp) :: inertia_rot = 34784179.0_wp !< Inertia of the rotor [kg/m2]
126	REAL(wp) :: inertia_gen = 534.116_wp !< Inertia of the generator [kg/m2]
127	REAL(wp) :: gen_eff = 0.944_wp !< Electric efficiency of the generator
128	REAL(wp) :: gear_eff = 1.0_wp !< Loss between rotor and generator
129	REAL(wp) :: air_dens = 1.225_wp !< Air density to convert to W [kg/m3]
130	REAL(wp) :: rated_genspeed = 121.6805_wp !< Rated generator speed [rad/s]
131	REAL(wp) :: max_torque_gen = 47402.91_wp !< Maximum of the generator torque [Nm]
132	REAL(wp) :: slope2 = 2.332287_wp !< Slope constant for region 2
133	REAL(wp) :: min_reg2 = 91.21091_wp !< Lower generator speed boundary of region 2 [rad/s]
134	REAL(wp) :: min_reg15 = 70.16224_wp !< Lower generator speed boundary of region 1.5 [rad/s]
135	REAL(wp) :: max_trq_rate = 15000.0_wp !< Max generator torque increase [Nm/s]
136	REAL(wp) :: pitch_rate = 8.0_wp !< Max pitch rate [degree/s]
137
138
139	!
140	!-- Variables specified in the namelist for yaw control
141
142	REAL(wp) :: yaw_speed = 0.005236_wp !< speed of the yaw actuator [rad/s]
143	REAL(wp) :: max_miss = 0.08726_wp !< maximum tolerated yaw missalignment [rad]
144	REAL(wp) :: min_miss = 0.008726_wp !< minimum yaw missalignment for which the actuator stops [rad]
145
146	!
147	!-- Set flag for output files TURBINE_PARAMETERS
148	TYPE file_status
149	LOGICAL :: opened, opened_before
150	END TYPE file_status
151
152	TYPE(file_status), DIMENSION(500) :: openfile_turb_mod = &
153	file_status(.FALSE.,.FALSE.)
154
155	!
156	!-- Variables for initialization of the turbine model
157
158	INTEGER(iwp) :: inot !< turbine loop index (turbine id)
159	INTEGER(iwp) :: nsegs_max !< maximum number of segments (all turbines, required for allocation of arrays)
160	INTEGER(iwp) :: nrings_max !< maximum number of rings (all turbines, required for allocation of arrays)
161	INTEGER(iwp) :: ring !< ring loop index (ring number)
162	INTEGER(iwp) :: rr_int !<
163	INTEGER(iwp) :: upper_end !<
164
165	INTEGER(iwp), DIMENSION(1) :: lct !<
166
167	INTEGER(iwp), DIMENSION(:), ALLOCATABLE :: i_hub !< index belonging to x-position of the turbine
168	INTEGER(iwp), DIMENSION(:), ALLOCATABLE :: i_smear !< index defining the area for the smearing of the forces (x-direction)
169	INTEGER(iwp), DIMENSION(:), ALLOCATABLE :: j_hub !< index belonging to y-position of the turbine
170	INTEGER(iwp), DIMENSION(:), ALLOCATABLE :: j_smear !< index defining the area for the smearing of the forces (y-direction)
171	INTEGER(iwp), DIMENSION(:), ALLOCATABLE :: k_hub !< index belonging to hub height
172	INTEGER(iwp), DIMENSION(:), ALLOCATABLE :: k_smear !< index defining the area for the smearing of the forces (z-direction)
173	INTEGER(iwp), DIMENSION(:), ALLOCATABLE :: nrings !< number of rings per turbine
174	INTEGER(iwp), DIMENSION(:), ALLOCATABLE :: nsegs_total !< total number of segments per turbine
175
176	INTEGER(iwp), DIMENSION(:,:), ALLOCATABLE :: nsegs !< number of segments per ring and turbine
177
178	!
179	!- parameters for the smearing from the rotor to the cartesian grid
180	REAL(wp) :: pol_a !< parameter for the polynomial smearing fct
181	REAL(wp) :: pol_b !< parameter for the polynomial smearing fct
182	REAL(wp) :: delta_t_factor !<
183	REAL(wp) :: eps_factor !<
184	REAL(wp) :: eps_min !<
185	REAL(wp) :: eps_min2 !<
186	REAL(wp) :: sqrt_arg !<
187
188	!
189	!-- Variables for the calculation of lift and drag coefficients
190	REAL(wp), DIMENSION(:), ALLOCATABLE :: ard !<
191	REAL(wp), DIMENSION(:), ALLOCATABLE :: crd !<
192	REAL(wp), DIMENSION(:), ALLOCATABLE :: delta_r !< radial segment length
193	REAL(wp), DIMENSION(:), ALLOCATABLE :: lrd !<
194
195	REAL(wp) :: accu_cl_cd_tab = 0.1_wp !< Accuracy of the interpolation of
196	!< the lift and drag coeff [deg]
197
198	REAL(wp), DIMENSION(:,:), ALLOCATABLE :: turb_cd_tab !< table of the blade drag coefficient
199	REAL(wp), DIMENSION(:,:), ALLOCATABLE :: turb_cl_tab !< table of the blade lift coefficient
200
201	REAL(wp), DIMENSION(:,:,:), ALLOCATABLE :: nac_cd_surf !< 3d field of the tower drag coefficient
202	REAL(wp), DIMENSION(:,:,:), ALLOCATABLE :: tow_cd_surf !< 3d field of the nacelle drag coefficient
203
204	!
205	!-- Variables for the calculation of the forces
206
207	REAL(wp) :: cur_r !<
208	REAL(wp) :: delta_t !< tangential segment length
209	REAL(wp) :: phi_rotor !<
210	REAL(wp) :: pre_factor !<
211	REAL(wp) :: torque_seg !<
212	REAL(wp) :: u_int_l !<
213	REAL(wp) :: u_int_u !<
214	REAL(wp) :: u_rot !<
215	REAL(wp) :: v_int_l !<
216	REAL(wp) :: v_int_u !<
217	REAL(wp) :: w_int_l !<
218	REAL(wp) :: w_int_u !<
219	!
220	!- Tendencies from the nacelle and tower thrust
221	REAL(wp) :: tend_nac_x = 0.0_wp !<
222	REAL(wp) :: tend_tow_x = 0.0_wp !<
223	REAL(wp) :: tend_nac_y = 0.0_wp !<
224	REAL(wp) :: tend_tow_y = 0.0_wp !<
225
226	REAL(wp), DIMENSION(:), ALLOCATABLE :: alpha_attack !<
227	REAL(wp), DIMENSION(:), ALLOCATABLE :: chord !<
228	REAL(wp), DIMENSION(:), ALLOCATABLE :: omega_gen !< curr. generator speed
229	REAL(wp), DIMENSION(:), ALLOCATABLE :: phi_rel !<
230	REAL(wp), DIMENSION(:), ALLOCATABLE :: pitch_add_old!<
231	REAL(wp), DIMENSION(:), ALLOCATABLE :: torque_total !<
232	REAL(wp), DIMENSION(:), ALLOCATABLE :: thrust_rotor !<
233	REAL(wp), DIMENSION(:), ALLOCATABLE :: turb_cl !<
234	REAL(wp), DIMENSION(:), ALLOCATABLE :: turb_cd !<
235	REAL(wp), DIMENSION(:), ALLOCATABLE :: vrel !<
236	REAL(wp), DIMENSION(:), ALLOCATABLE :: vtheta !<
237
238	REAL(wp), DIMENSION(:,:), ALLOCATABLE :: rbx, rby, rbz !< coordinates of the blade elements
239	REAL(wp), DIMENSION(:,:), ALLOCATABLE :: rotx, roty, rotz !< normal vectors to the rotor coordinates
240
241	!
242	!- Fields for the interpolation of velocities on the rotor grid
243	REAL(wp), DIMENSION(:,:,:), ALLOCATABLE :: u_int !<
244	REAL(wp), DIMENSION(:,:,:), ALLOCATABLE :: u_int_1_l !<
245	REAL(wp), DIMENSION(:,:,:), ALLOCATABLE :: v_int !<
246	REAL(wp), DIMENSION(:,:,:), ALLOCATABLE :: v_int_1_l !<
247	REAL(wp), DIMENSION(:,:,:), ALLOCATABLE :: w_int !<
248	REAL(wp), DIMENSION(:,:,:), ALLOCATABLE :: w_int_1_l !<
249
250	!
251	!- rotor tendencies on the segments
252	REAL(wp), DIMENSION(:), ALLOCATABLE :: thrust_seg !<
253	REAL(wp), DIMENSION(:), ALLOCATABLE :: torque_seg_y !<
254	REAL(wp), DIMENSION(:), ALLOCATABLE :: torque_seg_z !<
255
256	!
257	!- rotor tendencies on the rings
258	REAL(wp), DIMENSION(:,:), ALLOCATABLE :: thrust_ring !<
259	REAL(wp), DIMENSION(:,:), ALLOCATABLE :: torque_ring_y !<
260	REAL(wp), DIMENSION(:,:), ALLOCATABLE :: torque_ring_z !<
261
262	!
263	!- rotor tendencies on rotor grids for all turbines
264	REAL(wp), DIMENSION(:,:,:), ALLOCATABLE :: thrust !<
265	REAL(wp), DIMENSION(:,:,:), ALLOCATABLE :: torque_y !<
266	REAL(wp), DIMENSION(:,:,:), ALLOCATABLE :: torque_z !<
267
268	!
269	!- rotor tendencies on coordinate grid
270	REAL(wp), DIMENSION(:,:,:), ALLOCATABLE :: rot_tend_x !<
271	REAL(wp), DIMENSION(:,:,:), ALLOCATABLE :: rot_tend_y !<
272	REAL(wp), DIMENSION(:,:,:), ALLOCATABLE :: rot_tend_z !<
273	!
274	!- variables for the rotation of the rotor coordinates
275	REAL(wp), DIMENSION(1:100,1:3,1:3) :: rot_coord_trans !< matrix for rotation of rotor coordinates
276
277	REAL(wp), DIMENSION(1:3) :: rot_eigen_rad !<
278	REAL(wp), DIMENSION(1:3) :: rot_eigen_azi !<
279	REAL(wp), DIMENSION(1:3) :: rot_eigen_nor !<
280	REAL(wp), DIMENSION(1:3) :: re !<
281	REAL(wp), DIMENSION(1:3) :: rea !<
282	REAL(wp), DIMENSION(1:3) :: ren !<
283	REAL(wp), DIMENSION(1:3) :: rote !<
284	REAL(wp), DIMENSION(1:3) :: rota !<
285	REAL(wp), DIMENSION(1:3) :: rotn !<
286
287	!
288	!-- Fixed variables for the speed controller
289
290	LOGICAL :: start_up = .TRUE. !<
291
292	REAL(wp) :: Fcorner !< corner freq for the controller low pass filter
293	REAL(wp) :: min_reg25 !< min region 2.5
294	REAL(wp) :: om_rate !< rotor speed change
295	REAL(wp) :: slope15 !< slope in region 1.5
296	REAL(wp) :: slope25 !< slope in region 2.5
297	REAL(wp) :: trq_rate !< torque change
298	REAL(wp) :: vs_sysp !<
299	REAL(wp) :: lp_coeff !< coeff for the controller low pass filter
300
301	REAL(wp), DIMENSION(:), ALLOCATABLE :: omega_gen_old !< last gen. speed
302	REAL(wp), DIMENSION(:), ALLOCATABLE :: omega_gen_f !< filtered gen. sp
303	REAL(wp), DIMENSION(:), ALLOCATABLE :: omega_gen_f_old !< last filt. gen. sp
304	REAL(wp), DIMENSION(:), ALLOCATABLE :: torque_gen !< generator torque
305	REAL(wp), DIMENSION(:), ALLOCATABLE :: torque_gen_old !< last gen. torque
306
307	REAL(wp), DIMENSION(100) :: omega_rot_l = 0.0_wp !< local rot speed [rad/s]
308	!
309	!-- Fixed variables for the yaw controller
310
311	REAL(wp), DIMENSION(:) , ALLOCATABLE :: yawdir !< direction to yaw
312	REAL(wp), DIMENSION(:) , ALLOCATABLE :: phi_yaw_l !< local (cpu) yaw angle
313	REAL(wp), DIMENSION(:) , ALLOCATABLE :: wd30_l !< local (cpu) long running avg of the wd
314	REAL(wp), DIMENSION(:) , ALLOCATABLE :: wd2_l !< local (cpu) short running avg of the wd
315	REAL(wp), DIMENSION(:) , ALLOCATABLE :: wdir !< wind direction at hub
316	REAL(wp), DIMENSION(:) , ALLOCATABLE :: u_inflow !< wind speed at hub
317	REAL(wp), DIMENSION(:) , ALLOCATABLE :: wdir_l !<
318	REAL(wp), DIMENSION(:) , ALLOCATABLE :: u_inflow_l !<
319	REAL(wp), DIMENSION(:,:), ALLOCATABLE :: wd30 !<
320	REAL(wp), DIMENSION(:,:), ALLOCATABLE :: wd2 !<
321	LOGICAL, DIMENSION(1:100) :: doyaw = .FALSE. !<
322	INTEGER(iwp) :: WDLON !<
323	INTEGER(iwp) :: WDSHO !<
324
325
326	SAVE
327
328
329	INTERFACE wtm_parin
330	MODULE PROCEDURE wtm_parin
331	END INTERFACE wtm_parin
332
333	INTERFACE wtm_check_parameters
334	MODULE PROCEDURE wtm_check_parameters
335	END INTERFACE wtm_check_parameters
336
337	INTERFACE wtm_init_arrays
338	MODULE PROCEDURE wtm_init_arrays
339	END INTERFACE wtm_init_arrays
340
341	INTERFACE wtm_init
342	MODULE PROCEDURE wtm_init
343	END INTERFACE wtm_init
344
345	INTERFACE wtm_read_blade_tables
346	MODULE PROCEDURE wtm_read_blade_tables
347	END INTERFACE wtm_read_blade_tables
348
349	INTERFACE wtm_forces
350	MODULE PROCEDURE wtm_forces
351	MODULE PROCEDURE wtm_yawcontrol
352	END INTERFACE wtm_forces
353
354	INTERFACE wtm_rotate_rotor
355	MODULE PROCEDURE wtm_rotate_rotor
356	END INTERFACE wtm_rotate_rotor
357
358	INTERFACE wtm_speed_control
359	MODULE PROCEDURE wtm_init_speed_control
360	MODULE PROCEDURE wtm_speed_control
361	END INTERFACE wtm_speed_control
362
363	INTERFACE wtm_tendencies
364	MODULE PROCEDURE wtm_tendencies
365	MODULE PROCEDURE wtm_tendencies_ij
366	END INTERFACE wtm_tendencies
367
368
369	PUBLIC wtm_check_parameters, wtm_forces, wtm_init, wtm_init_arrays, &
370	wtm_parin, wtm_tendencies, wtm_tendencies_ij, wind_turbine
371
372	CONTAINS
373
374
375	!------------------------------------------------------------------------------!
376	! Description:
377	! ------------
378	!> Parin for &wind_turbine_par for wind turbine model
379	!------------------------------------------------------------------------------!
380	SUBROUTINE wtm_parin
381
382
383	IMPLICIT NONE
384
385	INTEGER(iwp) :: ierrn !<
386
387	CHARACTER (LEN=80) :: line !< dummy string that contains the current line of the parameter file
388
389	NAMELIST /wind_turbine_par/ air_dens, dtow, gear_eff, gear_ratio, &
390	gen_eff, inertia_gen, inertia_rot, max_miss, &
391	max_torque_gen, max_trq_rate, min_miss, &
392	min_reg15, min_reg2, nairfoils, nturbines, &
393	omega_rot, phi_yaw, pitch_add, pitch_control,&
394	rated_genspeed, rated_power, rcx, rcy, rcz, &
395	rnac, rr, segment_length, segment_width, &
396	slope2, speed_control, tilt, time_turbine_on,&
397	turb_cd_nacelle, turb_cd_tower, &
398	yaw_control, yaw_speed
399
400	!
401	!-- Try to find wind turbine model package
402	REWIND ( 11 )
403	line = ' '
404	DO WHILE ( INDEX( line, '&wind_turbine_par' ) == 0 )
405	READ ( 11, '(A)', END=10 ) line
406	ENDDO
407	BACKSPACE ( 11 )
408
409	!
410	!-- Read user-defined namelist
411	READ ( 11, wind_turbine_par, IOSTAT=ierrn )
412
413	IF ( ierrn < 0 ) THEN
414	message_string = 'errors in \$wind_turbine_par'
415	CALL message( 'wtm_parin', 'PA0???', 1, 2, 0, 6, 0 )
416	ENDIF
417
418	!
419	!-- Set flag that indicates that the wind turbine model is switched on
420	wind_turbine = .TRUE.
421
422	10 CONTINUE ! TBD Change from continue, mit ierrn machen
423
424
425	END SUBROUTINE wtm_parin
426
427	SUBROUTINE wtm_check_parameters
428
429
430	IMPLICIT NONE
431
432	IF ( ( .NOT.speed_control ) .AND. pitch_control ) THEN
433	message_string = 'pitch_control = .TRUE. requires '// &
434	'speed_control = .TRUE.'
435	CALL message( 'wtm_check_parameters', 'PA0???', 1, 2, 0, 6, 0 )
436	ENDIF
437
438	IF ( ANY( omega_rot(1:nturbines) <= 0.0 ) ) THEN
439	message_string = 'omega_rot <= 0.0, Please set omega_rot to ' // &
440	'a value larger than zero'
441	CALL message( 'wtm_check_parameters', 'PA0???', 1, 2, 0, 6, 0 )
442	ENDIF
443
444
445	IF ( ANY( rcx(1:nturbines) == 9999999.9_wp ) .OR. &
446	ANY( rcy(1:nturbines) == 9999999.9_wp ) .OR. &
447	ANY( rcz(1:nturbines) == 9999999.9_wp ) ) THEN
448
449	message_string = 'rcx, rcy, rcz ' // &
450	'have to be given for each turbine.'
451	CALL message( 'wtm_check_parameters', 'PA0???', 1, 2, 0, 6, 0 )
452
453	ENDIF
454
455
456	END SUBROUTINE wtm_check_parameters
457
458
459	!------------------------------------------------------------------------------!
460	! Description:
461	! ------------
462	!> Allocate wind turbine model arrays
463	!------------------------------------------------------------------------------!
464	SUBROUTINE wtm_init_arrays
465
466
467	IMPLICIT NONE
468
469	REAL(wp) :: delta_r_factor !<
470	REAL(wp) :: delta_r_init !<
471
472	!
473	!-- To be able to allocate arrays with dimension of rotor rings and segments,
474	!-- the maximum possible numbers of rings and segments have to be calculated:
475
476	ALLOCATE( nrings(1:nturbines) )
477	ALLOCATE( delta_r(1:nturbines) )
478
479	nrings(:) = 0
480	delta_r(:) = 0.0_wp
481
482	!
483	!-- Thickness (radial) of each ring and length (tangential) of each segment:
484	delta_r_factor = segment_width
485	delta_t_factor = segment_length
486	delta_r_init = delta_r_factor * MIN( dx, dy, dz)
487	delta_t = delta_t_factor * MIN( dx, dy, dz)
488
489	DO inot = 1, nturbines
490	!
491	!-- Determine number of rings:
492	nrings(inot) = NINT( rr(inot) / delta_r_init )
493
494	delta_r(inot) = rr(inot) / nrings(inot)
495
496	ENDDO
497
498	nrings_max = MAXVAL(nrings)
499
500	ALLOCATE( nsegs(1:nrings_max,1:nturbines) )
501	ALLOCATE( nsegs_total(1:nturbines) )
502
503	nsegs(:,:) = 0
504	nsegs_total(:) = 0
505
506
507	DO inot = 1, nturbines
508	DO ring = 1, nrings(inot)
509	!
510	!-- Determine number of segments for each ring:
511	nsegs(ring,inot) = MAX( 8, CEILING( delta_r_factor * pi * &
512	( 2.0_wp * ring - 1.0_wp ) / &
513	delta_t_factor ) )
514	ENDDO
515	!
516	!-- Total sum of all rotor segments:
517	nsegs_total(inot) = SUM( nsegs(:,inot) )
518
519	ENDDO
520
521	!
522	!-- Maximum number of segments per ring:
523	nsegs_max = MAXVAL(nsegs)
524
525	!!
526	!!-- TODO: Folgendes im Header ausgeben!
527	! IF ( myid == 0 ) THEN
528	! PRINT*, 'nrings(1) = ', nrings(1)
529	! PRINT*, '--------------------------------------------------'
530	! PRINT*, 'nsegs(:,1) = ', nsegs(:,1)
531	! PRINT*, '--------------------------------------------------'
532	! PRINT*, 'nrings_max = ', nrings_max
533	! PRINT*, 'nsegs_max = ', nsegs_max
534	! PRINT*, 'nsegs_total(1) = ', nsegs_total(1)
535	! ENDIF
536
537
538	!
539	!-- Allocate 1D arrays (dimension = number of turbines)
540	ALLOCATE( i_hub(1:nturbines) )
541	ALLOCATE( i_smear(1:nturbines) )
542	ALLOCATE( j_hub(1:nturbines) )
543	ALLOCATE( j_smear(1:nturbines) )
544	ALLOCATE( k_hub(1:nturbines) )
545	ALLOCATE( k_smear(1:nturbines) )
546	ALLOCATE( torque_total(1:nturbines) )
547	ALLOCATE( thrust_rotor(1:nturbines) )
548
549	!
550	!-- Allocation of the 1D arrays for speed pitch_control
551	ALLOCATE( omega_gen(1:nturbines) )
552	ALLOCATE( omega_gen_old(1:nturbines) )
553	ALLOCATE( omega_gen_f(1:nturbines) )
554	ALLOCATE( omega_gen_f_old(1:nturbines) )
555	ALLOCATE( pitch_add_old(1:nturbines) )
556	ALLOCATE( torque_gen(1:nturbines) )
557	ALLOCATE( torque_gen_old(1:nturbines) )
558
559	!
560	!-- Allocation of the 1D arrays for yaw control
561	ALLOCATE( yawdir(1:nturbines) )
562	ALLOCATE( u_inflow(1:nturbines) )
563	ALLOCATE( wdir(1:nturbines) )
564	ALLOCATE( u_inflow_l(1:nturbines) )
565	ALLOCATE( wdir_l(1:nturbines) )
566	ALLOCATE( phi_yaw_l(1:nturbines) )
567
568	!
569	!-- Allocate 1D arrays (dimension = number of rotor segments)
570	ALLOCATE( alpha_attack(1:nsegs_max) )
571	ALLOCATE( chord(1:nsegs_max) )
572	ALLOCATE( phi_rel(1:nsegs_max) )
573	ALLOCATE( thrust_seg(1:nsegs_max) )
574	ALLOCATE( torque_seg_y(1:nsegs_max) )
575	ALLOCATE( torque_seg_z(1:nsegs_max) )
576	ALLOCATE( turb_cd(1:nsegs_max) )
577	ALLOCATE( turb_cl(1:nsegs_max) )
578	ALLOCATE( vrel(1:nsegs_max) )
579	ALLOCATE( vtheta(1:nsegs_max) )
580
581	!
582	!-- Allocate 2D arrays (dimension = number of rotor rings and segments)
583	ALLOCATE( rbx(1:nrings_max,1:nsegs_max) )
584	ALLOCATE( rby(1:nrings_max,1:nsegs_max) )
585	ALLOCATE( rbz(1:nrings_max,1:nsegs_max) )
586	ALLOCATE( thrust_ring(1:nrings_max,1:nsegs_max) )
587	ALLOCATE( torque_ring_y(1:nrings_max,1:nsegs_max) )
588	ALLOCATE( torque_ring_z(1:nrings_max,1:nsegs_max) )
589
590	!
591	!-- Allocate additional 2D arrays
592	ALLOCATE( rotx(1:nturbines,1:3) )
593	ALLOCATE( roty(1:nturbines,1:3) )
594	ALLOCATE( rotz(1:nturbines,1:3) )
595
596	!
597	!-- Allocate 3D arrays (dimension = number of grid points)
598	ALLOCATE( nac_cd_surf(nzb:nzt+1,nysg:nyng,nxlg:nxrg) )
599	ALLOCATE( rot_tend_x(nzb:nzt+1,nysg:nyng,nxlg:nxrg) )
600	ALLOCATE( rot_tend_y(nzb:nzt+1,nysg:nyng,nxlg:nxrg) )
601	ALLOCATE( rot_tend_z(nzb:nzt+1,nysg:nyng,nxlg:nxrg) )
602	ALLOCATE( thrust(nzb:nzt+1,nysg:nyng,nxlg:nxrg) )
603	ALLOCATE( torque_y(nzb:nzt+1,nysg:nyng,nxlg:nxrg) )
604	ALLOCATE( torque_z(nzb:nzt+1,nysg:nyng,nxlg:nxrg) )
605	ALLOCATE( tow_cd_surf(nzb:nzt+1,nysg:nyng,nxlg:nxrg) )
606
607	!
608	!-- Allocate additional 3D arrays
609	ALLOCATE( u_int(1:nturbines,1:nrings_max,1:nsegs_max) )
610	ALLOCATE( u_int_1_l(1:nturbines,1:nrings_max,1:nsegs_max) )
611	ALLOCATE( v_int(1:nturbines,1:nrings_max,1:nsegs_max) )
612	ALLOCATE( v_int_1_l(1:nturbines,1:nrings_max,1:nsegs_max) )
613	ALLOCATE( w_int(1:nturbines,1:nrings_max,1:nsegs_max) )
614	ALLOCATE( w_int_1_l(1:nturbines,1:nrings_max,1:nsegs_max) )
615
616	!
617	!-- All of the arrays are initialized with a value of zero:
618	i_hub(:) = 0
619	i_smear(:) = 0
620	j_hub(:) = 0
621	j_smear(:) = 0
622	k_hub(:) = 0
623	k_smear(:) = 0
624
625	torque_total(:) = 0.0_wp
626	thrust_rotor(:) = 0.0_wp
627
628	omega_gen(:) = 0.0_wp
629	omega_gen_old(:) = 0.0_wp
630	omega_gen_f(:) = 0.0_wp
631	omega_gen_f_old(:) = 0.0_wp
632	pitch_add_old(:) = 0.0_wp
633	torque_gen(:) = 0.0_wp
634	torque_gen_old(:) = 0.0_wp
635
636	yawdir(:) = 0.0_wp
637	wdir(:) = 0.0_wp
638	u_inflow(:) = 0.0_wp
639
640	!
641	!-- Allocate 1D arrays (dimension = number of rotor segments)
642	alpha_attack(:) = 0.0_wp
643	chord(:) = 0.0_wp
644	phi_rel(:) = 0.0_wp
645	thrust_seg(:) = 0.0_wp
646	torque_seg_y(:) = 0.0_wp
647	torque_seg_z(:) = 0.0_wp
648	turb_cd(:) = 0.0_wp
649	turb_cl(:) = 0.0_wp
650	vrel(:) = 0.0_wp
651	vtheta(:) = 0.0_wp
652
653	rbx(:,:) = 0.0_wp
654	rby(:,:) = 0.0_wp
655	rbz(:,:) = 0.0_wp
656	thrust_ring(:,:) = 0.0_wp
657	torque_ring_y(:,:) = 0.0_wp
658	torque_ring_z(:,:) = 0.0_wp
659
660	rotx(:,:) = 0.0_wp
661	roty(:,:) = 0.0_wp
662	rotz(:,:) = 0.0_wp
663	turb_cl_tab(:,:) = 0.0_wp
664	turb_cd_tab(:,:) = 0.0_wp
665
666	nac_cd_surf(:,:,:) = 0.0_wp
667	rot_tend_x(:,:,:) = 0.0_wp
668	rot_tend_y(:,:,:) = 0.0_wp
669	rot_tend_z(:,:,:) = 0.0_wp
670	thrust(:,:,:) = 0.0_wp
671	torque_y(:,:,:) = 0.0_wp
672	torque_z(:,:,:) = 0.0_wp
673	tow_cd_surf(:,:,:) = 0.0_wp
674
675	u_int(:,:,:) = 0.0_wp
676	u_int_1_l(:,:,:) = 0.0_wp
677	v_int(:,:,:) = 0.0_wp
678	v_int_1_l(:,:,:) = 0.0_wp
679	w_int(:,:,:) = 0.0_wp
680	w_int_1_l(:,:,:) = 0.0_wp
681
682
683	END SUBROUTINE wtm_init_arrays
684
685
686	!------------------------------------------------------------------------------!
687	! Description:
688	! ------------
689	!> Initialization of the wind turbine model
690	!------------------------------------------------------------------------------!
691	SUBROUTINE wtm_init
692
693
694	IMPLICIT NONE
695
696	INTEGER(iwp) :: i !< running index
697	INTEGER(iwp) :: j !< running index
698	INTEGER(iwp) :: k !< running index
699
700	!
701	!-- Help variables for the smearing function
702	REAL(wp) :: eps_kernel !<
703
704	!
705	!-- Help variables for calculation of the tower drag
706	INTEGER(iwp) :: tower_n !<
707	INTEGER(iwp) :: tower_s !<
708	!
709	!-- Help variables for the calulaction of the nacelle drag
710	INTEGER(iwp) :: i_ip !<
711	INTEGER(iwp) :: i_ipg !<
712
713	REAL(wp) :: yvalue
714	REAL(wp) :: dy_int !<
715	REAL(wp) :: dz_int !<
716
717	REAL(wp), DIMENSION(:,:), ALLOCATABLE :: circle_points !<
718
719	INTEGER(iwp), DIMENSION(:), ALLOCATABLE :: index_nacb !<
720	INTEGER(iwp), DIMENSION(:), ALLOCATABLE :: index_nacl !<
721	INTEGER(iwp), DIMENSION(:), ALLOCATABLE :: index_nacr !<
722	INTEGER(iwp), DIMENSION(:), ALLOCATABLE :: index_nact !<
723
724	ALLOCATE( index_nacb(1:nturbines) )
725	ALLOCATE( index_nacl(1:nturbines) )
726	ALLOCATE( index_nacr(1:nturbines) )
727	ALLOCATE( index_nact(1:nturbines) )
728
729
730	IF ( speed_control) THEN
731
732	CALL wtm_speed_control
733
734	ENDIF
735
736	!
737	!------------------------------------------------------------------------------!
738	!-- Calculation of parameters for the regularization kernel
739	!-- (smearing of the forces)
740	!------------------------------------------------------------------------------!
741	!
742	!-- In the following, some of the required parameters for the smearing will
743	!-- be calculated:
744
745	!-- The kernel is set equal to twice the grid spacing which has turned out to
746	!-- be a reasonable value (see e.g. Troldborg et al. (2013), Wind Energy,
747	!-- DOI: 10.1002/we.1608):
748	eps_kernel = 2.0_wp * dx
749	!
750	!-- The zero point (eps_min) of the polynomial function must be the following
751	!-- if the integral of the polynomial function (for values < eps_min) shall
752	!-- be equal to the integral of the Gaussian function used before:
753	eps_min = ( 105.0_wp / 32.0_wp )*( 1.0_wp / 3.0_wp ) &
754	pi*( 1.0_wp / 6.0_wp ) eps_kernel
755	!
756	!-- Square of eps_min:
757	eps_min2 = eps_min**2
758	!
759	!-- Parameters in the polynomial function:
760	pol_a = 1.0_wp / eps_min**4
761	pol_b = 2.0_wp / eps_min**2
762	!
763	!-- Normalization factor which is the inverse of the integral of the smearing
764	!-- function:
765	eps_factor = 105.0_wp / ( 32.0_wp * pi * eps_min**3 )
766
767	!-- Change tilt angle to rad:
768	tilt = tilt * pi / 180.0_wp
769
770	!
771	!-- Change yaw angle to rad:
772	phi_yaw(:) = phi_yaw(:) * pi / 180.0_wp
773
774
775	DO inot = 1, nturbines
776	!
777	!-- Rotate the rotor coordinates in case yaw and tilt are defined
778	CALL wtm_rotate_rotor( inot )
779
780	!
781	!-- Determine the indices of the hub height
782	i_hub(inot) = INT( rcx(inot) / dx )
783	j_hub(inot) = INT( ( rcy(inot) + 0.5_wp * dy ) / dy )
784	k_hub(inot) = INT( ( rcz(inot) + 0.5_wp * dz ) / dz )
785
786	!
787	!-- Determining the area to which the smearing of the forces is applied.
788	!-- As smearing now is effectively applied only for distances smaller than
789	!-- eps_min, the smearing area can be further limited and regarded as a
790	!-- function of eps_min:
791	i_smear(inot) = CEILING( ( rr(inot) + eps_min ) / dx )
792	j_smear(inot) = CEILING( ( rr(inot) + eps_min ) / dy )
793	k_smear(inot) = CEILING( ( rr(inot) + eps_min ) / dz )
794
795	ENDDO
796
797	!
798	!------------------------------------------------------------------------------!
799	!-- Determine the area within each grid cell that overlaps with the area
800	!-- of the nacelle and the tower (needed for calculation of the forces)
801	!------------------------------------------------------------------------------!
802	!
803	!-- Note: so far this is only a 2D version, in that the mean flow is
804	!-- perpendicular to the rotor area.
805
806	!
807	!-- Allocation of the array containing information on the intersection points
808	!-- between rotor disk and the numerical grid:
809	upper_end = ( ny + 1 ) * 10000
810
811	ALLOCATE( circle_points(1:2,1:upper_end) )
812
813	circle_points(:,:) = 0.0_wp
814
815
816	DO inot = 1, nturbines ! loop over number of turbines
817	!
818	!-- Determine the grid index (u-grid) that corresponds to the location of
819	!-- the rotor center (reduces the amount of calculations in the case that
820	!-- the mean flow is perpendicular to the rotor area):
821	i = i_hub(inot)
822
823	!
824	!-- Determine the left and the right edge of the nacelle (corresponding
825	!-- grid point indices):
826	index_nacl(inot) = INT( ( rcy(inot) - rnac(inot) + 0.5_wp * dy ) / dy )
827	index_nacr(inot) = INT( ( rcy(inot) + rnac(inot) + 0.5_wp * dy ) / dy )
828	!
829	!-- Determine the bottom and the top edge of the nacelle (corresponding
830	!-- grid point indices).The grid point index has to be increased by 1, as
831	!-- the first level for the u-component (index 0) is situated below the
832	!-- surface. All points between z=0 and z=dz/s would already be contained
833	!-- in grid box 1.
834	index_nacb(inot) = INT( ( rcz(inot) - rnac(inot) ) / dz ) + 1
835	index_nact(inot) = INT( ( rcz(inot) + rnac(inot) ) / dz ) + 1
836
837	!
838	!-- Determine the indices of the grid boxes containing the left and
839	!-- the right boundaries of the tower:
840	tower_n = ( rcy(inot) + 0.5_wp * dtow(inot) - 0.5_wp * dy ) / dy
841	tower_s = ( rcy(inot) - 0.5_wp * dtow(inot) - 0.5_wp * dy ) / dy
842
843	!
844	!-- Determine the fraction of the grid box area overlapping with the tower
845	!-- area and multiply it with the drag of the tower:
846	IF ( ( nxlg <= i ) .AND. ( nxrg >= i ) ) THEN
847
848	DO j = nys, nyn
849	!
850	!-- Loop from south to north boundary of tower
851	IF ( ( j >= tower_s ) .AND. ( j <= tower_n ) ) THEN
852
853	DO k = nzb, nzt
854
855	IF ( k == k_hub(inot) ) THEN
856	IF ( tower_n - tower_s >= 1 ) THEN
857	!
858	!-- leftmost and rightmost grid box:
859	IF ( j == tower_s ) THEN
860	tow_cd_surf(k,j,i) = ( rcz(inot) - &
861	( k_hub(inot) * dz - 0.5_wp * dz ) ) * & ! extension in z-direction
862	( ( tower_s + 1.0_wp + 0.5_wp ) * dy - &
863	( rcy(inot) - 0.5_wp * dtow(inot) ) ) * & ! extension in y-direction
864	turb_cd_tower(inot)
865	ELSEIF ( j == tower_n ) THEN
866	tow_cd_surf(k,j,i) = ( rcz(inot) - &
867	( k_hub(inot) * dz - 0.5_wp * dz ) ) * & ! extension in z-direction
868	( ( rcy(inot) + 0.5_wp * dtow(inot) ) - &
869	( tower_n + 0.5_wp ) * dy ) * & ! extension in y-direction
870	turb_cd_tower(inot)
871	!
872	!-- grid boxes inbetween
873	!-- (where tow_cd_surf = grid box area):
874	ELSE
875	tow_cd_surf(k,j,i) = ( rcz(inot) - &
876	( k_hub(inot) * dz - 0.5_wp * dz ) ) * &
877	dy * turb_cd_tower(inot)
878	ENDIF
879	!
880	!-- tower lies completely within one grid box:
881	ELSE
882	tow_cd_surf(k,j,i) = ( rcz(inot) - &
883	( k_hub(inot) * dz - 0.5_wp * dz ) ) * &
884	dtow(inot) * turb_cd_tower(inot)
885	ENDIF
886	!
887	!-- In case that k is smaller than k_hub the following actions
888	!-- are carried out:
889	ELSEIF ( k < k_hub(inot) ) THEN
890
891	IF ( ( tower_n - tower_s ) >= 1 ) THEN
892	!
893	!-- leftmost and rightmost grid box:
894	IF ( j == tower_s ) THEN
895	tow_cd_surf(k,j,i) = dz * ( &
896	( tower_s + 1 + 0.5_wp ) * dy - &
897	( rcy(inot) - 0.5_wp * dtow(inot) ) &
898	) * turb_cd_tower(inot)
899	ELSEIF ( j == tower_n ) THEN
900	tow_cd_surf(k,j,i) = dz * ( &
901	( rcy(inot) + 0.5_wp * dtow(inot) ) - &
902	( tower_n + 0.5_wp ) * dy &
903	) * turb_cd_tower(inot)
904	!
905	!-- grid boxes inbetween
906	!-- (where tow_cd_surf = grid box area):
907	ELSE
908	tow_cd_surf(k,j,i) = dz * dy * turb_cd_tower(inot)
909	ENDIF
910	!
911	!-- tower lies completely within one grid box:
912	ELSE
913	tow_cd_surf(k,j,i) = dz * dtow(inot) * &
914	turb_cd_tower(inot)
915	ENDIF ! end if larger than grid box
916
917	ENDIF ! end if k == k_hub
918
919	ENDDO ! end loop over k
920
921	ENDIF ! end if inside north and south boundary of tower
922
923	ENDDO ! end loop over j
924
925	ENDIF ! end if hub inside domain + ghostpoints
926
927
928	CALL exchange_horiz( tow_cd_surf, nbgp )
929
930	!
931	!-- Calculation of the nacelle area
932	!-- CAUTION: Currently disabled due to segmentation faults on the FLOW HPC
933	!-- cluster (Oldenburg)
934	!!
935	!!-- Tabulate the points on the circle that are required in the following for
936	!!-- the calculation of the Riemann integral (node points; they are called
937	!!-- circle_points in the following):
938	!
939	! dy_int = dy / 10000.0_wp
940	!
941	! DO i_ip = 1, upper_end
942	! yvalue = dy_int * ( i_ip - 0.5_wp ) + 0.5_wp * dy !<--- segmentation fault
943	! sqrt_arg = rnac(inot)2 - ( yvalue - rcy(inot) )2 !<--- segmentation fault
944	! IF ( sqrt_arg >= 0.0_wp ) THEN
945	!!
946	!!-- bottom intersection point
947	! circle_points(1,i_ip) = rcz(inot) - SQRT( sqrt_arg )
948	!!
949	!!-- top intersection point
950	! circle_points(2,i_ip) = rcz(inot) + SQRT( sqrt_arg ) !<--- segmentation fault
951	! ELSE
952	! circle_points(:,i_ip) = -111111 !<--- segmentation fault
953	! ENDIF
954	! ENDDO
955	!
956	!
957	! DO j = nys, nyn
958	!!
959	!!-- In case that the grid box is located completely outside the nacelle
960	!!-- (y) it can automatically be stated that there is no overlap between
961	!!-- the grid box and the nacelle and consequently we can set
962	!!-- nac_cd_surf(:,j,i) = 0.0:
963	! IF ( ( j >= index_nacl(inot) ) .AND. ( j <= index_nacr(inot) ) ) THEN
964	! DO k = nzb+1, nzt
965	!!
966	!!-- In case that the grid box is located completely outside the
967	!!-- nacelle (z) it can automatically be stated that there is no
968	!!-- overlap between the grid box and the nacelle and consequently
969	!!-- we can set nac_cd_surf(k,j,i) = 0.0:
970	! IF ( ( k >= index_nacb(inot) ) .OR. &
971	! ( k <= index_nact(inot) ) ) THEN
972	!!
973	!!-- For all other cases Riemann integrals are calculated.
974	!!-- Here, the points on the circle that have been determined
975	!!-- above are used in order to calculate the overlap between the
976	!!-- gridbox and the nacelle area (area approached by 10000
977	!!-- rectangulars dz_int * dy_int):
978	! DO i_ipg = 1, 10000
979	! dz_int = dz
980	! i_ip = j * 10000 + i_ipg
981	!!
982	!!-- Determine the vertical extension dz_int of the circle
983	!!-- within the current grid box:
984	! IF ( ( circle_points(2,i_ip) < zw(k) ) .AND. & !<--- segmentation fault
985	! ( circle_points(2,i_ip) >= zw(k-1) ) ) THEN
986	! dz_int = dz_int - & !<--- segmentation fault
987	! ( zw(k) - circle_points(2,i_ip) )
988	! ENDIF
989	! IF ( ( circle_points(1,i_ip) <= zw(k) ) .AND. & !<--- segmentation fault
990	! ( circle_points(1,i_ip) > zw(k-1) ) ) THEN
991	! dz_int = dz_int - &
992	! ( circle_points(1,i_ip) - zw(k-1) )
993	! ENDIF
994	! IF ( zw(k-1) > circle_points(2,i_ip) ) THEN
995	! dz_int = 0.0_wp
996	! ENDIF
997	! IF ( zw(k) < circle_points(1,i_ip) ) THEN
998	! dz_int = 0.0_wp
999	! ENDIF
1000	! IF ( ( nxlg <= i ) .AND. ( nxrg >= i ) ) THEN
1001	! nac_cd_surf(k,j,i) = nac_cd_surf(k,j,i) + & !<--- segmentation fault
1002	! dy_int * dz_int * turb_cd_nacelle(inot)
1003	! ENDIF
1004	! ENDDO
1005	! ENDIF
1006	! ENDDO
1007	! ENDIF
1008	!
1009	! ENDDO
1010	!
1011	! CALL exchange_horiz( nac_cd_surf, nbgp ) !<--- segmentation fault
1012
1013	ENDDO ! end of loop over turbines
1014
1015	tow_cd_surf = tow_cd_surf / ( dx * dy * dz ) ! Normalize tower drag
1016	nac_cd_surf = nac_cd_surf / ( dx * dy * dz ) ! Normalize nacelle drag
1017
1018	CALL wtm_read_blade_tables
1019
1020	END SUBROUTINE wtm_init
1021
1022
1023	!------------------------------------------------------------------------------!
1024	! Description:
1025	! ------------
1026	!> Read in layout of the rotor blade , the lift and drag tables
1027	!> and the distribution of lift and drag tables along the blade
1028	!------------------------------------------------------------------------------!
1029	!
1030	SUBROUTINE wtm_read_blade_tables
1031
1032
1033	IMPLICIT NONE
1034
1035	INTEGER(iwp) :: ii !< running index
1036	INTEGER(iwp) :: jj !< running index
1037
1038	INTEGER(iwp) :: ierrn !<
1039
1040	CHARACTER(200) :: chmess !< Read in string
1041
1042	INTEGER(iwp) :: dlen !< no. rows of local table
1043	INTEGER(iwp) :: dlenbl !< no. rows of cd, cl table
1044	INTEGER(iwp) :: ialpha !< table position of current alpha value
1045	INTEGER(iwp) :: iialpha !<
1046	INTEGER(iwp) :: iir !<
1047	INTEGER(iwp) :: radres !< radial resolution
1048	INTEGER(iwp) :: t1 !< no. of airfoil
1049	INTEGER(iwp) :: t2 !< no. of airfoil
1050	INTEGER(iwp) :: trow !<
1051	INTEGER(iwp) :: dlenbl_int !< no. rows of interpolated cd, cl tables
1052
1053	REAL(wp) :: alpha_attack_i !<
1054	REAL(wp) :: weight_a !<
1055	REAL(wp) :: weight_b !<
1056
1057	INTEGER(iwp), DIMENSION(:), ALLOCATABLE :: ttoint1 !<
1058	INTEGER(iwp), DIMENSION(:), ALLOCATABLE :: ttoint2 !<
1059
1060	REAL(wp), DIMENSION(:), ALLOCATABLE :: turb_cd_sel1 !<
1061	REAL(wp), DIMENSION(:), ALLOCATABLE :: turb_cd_sel2 !<
1062	REAL(wp), DIMENSION(:), ALLOCATABLE :: turb_cl_sel1 !<
1063	REAL(wp), DIMENSION(:), ALLOCATABLE :: turb_cl_sel2 !<
1064	REAL(wp), DIMENSION(:), ALLOCATABLE :: read_cl_cd !< read in var array
1065
1066	REAL(wp), DIMENSION(:), ALLOCATABLE :: alpha_attack_tab !<
1067	REAL(wp), DIMENSION(:), ALLOCATABLE :: trad1 !<
1068	REAL(wp), DIMENSION(:), ALLOCATABLE :: trad2 !<
1069	REAL(wp), DIMENSION(:,:), ALLOCATABLE :: turb_cd_table !<
1070	REAL(wp), DIMENSION(:,:), ALLOCATABLE :: turb_cl_table !<
1071
1072	ALLOCATE ( read_cl_cd(1:2*nairfoils+1) )
1073
1074	!
1075	!-- Read in the distribution of lift and drag tables along the blade, the
1076	!-- layout of the rotor blade and the lift and drag tables:
1077
1078	OPEN ( 201, FILE='WTM_DATA', STATUS='OLD', FORM='FORMATTED', IOSTAT=ierrn )
1079
1080	IF ( ierrn /= 0 ) THEN
1081	message_string = 'file WTM_DATA does not exist'
1082	CALL message( 'wtm_init', 'PA0???', 1, 2, 0, 6, 0 )
1083	ENDIF
1084	!
1085	!-- Read distribution table:
1086
1087	dlen = 0
1088
1089	READ ( 201, '(3/)' )
1090
1091	rloop3: DO
1092	READ ( 201, *, IOSTAT=ierrn ) chmess
1093	IF ( ierrn < 0 .OR. chmess == '#' .OR. chmess == '') EXIT rloop3
1094	dlen = dlen + 1
1095	ENDDO rloop3
1096
1097	ALLOCATE( trad1(1:dlen), trad2(1:dlen), ttoint1(1:dlen), ttoint2(1:dlen))
1098
1099	DO jj = 1,dlen+1
1100	BACKSPACE ( 201, IOSTAT=ierrn )
1101	ENDDO
1102
1103	DO jj = 1,dlen
1104	READ ( 201, * ) trad1(jj), trad2(jj), ttoint1(jj), ttoint2(jj)
1105	ENDDO
1106
1107	!
1108	!-- Read layout table:
1109
1110	dlen = 0
1111
1112	READ ( 201, '(3/)')
1113
1114	rloop1: DO
1115	READ ( 201, *, IOSTAT=ierrn ) chmess
1116	IF ( ierrn < 0 .OR. chmess == '#' .OR. chmess == '') EXIT rloop1
1117	dlen = dlen + 1
1118	ENDDO rloop1
1119
1120	ALLOCATE( lrd(1:dlen), ard(1:dlen), crd(1:dlen) )
1121	DO jj = 1, dlen+1
1122	BACKSPACE ( 201, IOSTAT=ierrn )
1123	ENDDO
1124	DO jj = 1, dlen
1125	READ ( 201, * ) lrd(jj), ard(jj), crd(jj)
1126	ENDDO
1127
1128	!
1129	!-- Read tables (turb_cl(alpha),turb_cd(alpha) for the different profiles:
1130
1131	dlen = 0
1132
1133	READ ( 201, '(3/)' )
1134
1135	rloop2: DO
1136	READ ( 201, *, IOSTAT=ierrn ) chmess
1137	IF ( ierrn < 0 .OR. chmess == '#' .OR. chmess == '') EXIT rloop2
1138	dlen = dlen + 1
1139	ENDDO rloop2
1140
1141	ALLOCATE( alpha_attack_tab(1:dlen), turb_cl_table(1:dlen,1:nairfoils), &
1142	turb_cd_table(1:dlen,1:nairfoils) )
1143
1144	DO jj = 1,dlen+1
1145	BACKSPACE ( 201, IOSTAT=ierrn )
1146	ENDDO
1147
1148	DO jj = 1,dlen
1149	READ ( 201, * ) read_cl_cd
1150	alpha_attack_tab(jj) = read_cl_cd(1)
1151	DO ii= 1, nairfoils
1152	turb_cl_table(jj,ii) = read_cl_cd(ii*2)
1153	turb_cd_table(jj,ii) = read_cl_cd(ii*2+1)
1154	ENDDO
1155
1156	ENDDO
1157
1158	dlenbl = dlen
1159
1160	CLOSE ( 201 )
1161
1162	!
1163	!-- For each possible radial position (resolution: 0.1 m --> 630 values) and
1164	!-- each possible angle of attack (resolution: 0.01 degrees --> 36000 values!)
1165	!-- determine the lift and drag coefficient by interpolating between the
1166	!-- tabulated values of each table (interpolate to current angle of attack)
1167	!-- and between the tables (interpolate to current radial position):
1168
1169	ALLOCATE( turb_cl_sel1(0:dlenbl) )
1170	ALLOCATE( turb_cl_sel2(0:dlenbl) )
1171	ALLOCATE( turb_cd_sel1(0:dlenbl) )
1172	ALLOCATE( turb_cd_sel2(0:dlenbl) )
1173
1174	radres = INT( rr(1) * 10.0_wp ) + 1_iwp
1175	dlenbl_int = INT( 360.0_wp / accu_cl_cd_tab ) + 1_iwp
1176
1177
1178	ALLOCATE( turb_cl_tab(0:dlenbl_int,1:radres) )
1179	ALLOCATE( turb_cd_tab(0:dlenbl_int,1:radres) )
1180
1181
1182	DO iir = 1, radres ! loop over radius
1183
1184	DO iialpha = 1, dlenbl_int ! loop over angles
1185
1186	cur_r = ( iir - 1_iwp ) * 0.1_wp
1187	alpha_attack_i = -180.0_wp + REAL( iialpha-1 ) * accu_cl_cd_tab
1188	ialpha = 1
1189
1190	DO WHILE ( alpha_attack_i > alpha_attack_tab(ialpha) )
1191	ialpha = ialpha + 1
1192	ENDDO
1193	!
1194	!-- Find position in table
1195	lct = MINLOC( ABS( trad1 - cur_r ) )
1196	! lct(1) = lct(1)
1197
1198	IF ( ( trad1(lct(1)) - cur_r ) .GT. 0.0 ) THEN
1199	lct(1) = lct(1) - 1
1200	ENDIF
1201
1202	trow = lct(1)
1203	!
1204	!-- Calculate weights for interpolation
1205	weight_a = ( trad2(trow) - cur_r ) / ( trad2(trow) - trad1(trow) )
1206	weight_b = ( cur_r - trad1(trow) ) / ( trad2(trow) - trad1(trow) )
1207	t1 = ttoint1(trow)
1208	t2 = ttoint2(trow)
1209
1210	IF ( t1 .EQ. t2 ) THEN ! if both are the same, the weights are NaN
1211	weight_a = 0.5_wp ! then do interpolate in between same twice
1212	weight_b = 0.5_wp ! using 0.5 as weight
1213	ENDIF
1214
1215	IF ( t1 == 0 .AND. t2 == 0 ) THEN
1216	turb_cd_sel1 = 0.0_wp
1217	turb_cd_sel2 = 0.0_wp
1218	turb_cl_sel1 = 0.0_wp
1219	turb_cl_sel2 = 0.0_wp
1220	ELSE
1221	turb_cd_sel1 = turb_cd_table(:,t1)
1222	turb_cd_sel2 = turb_cd_table(:,t2)
1223	turb_cl_sel1 = turb_cl_table(:,t1)
1224	turb_cl_sel2 = turb_cl_table(:,t2)
1225	ENDIF
1226
1227	!
1228	!-- Interpolation of lift and drag coefficiencts on fine grid of radius
1229	!-- segments and angles of attack
1230
1231	turb_cl_tab(iialpha,iir) = ( alpha_attack_tab(ialpha) - &
1232	alpha_attack_i ) / &
1233	( alpha_attack_tab(ialpha) - &
1234	alpha_attack_tab(ialpha-1) ) * &
1235	( weight_a * turb_cl_sel1(ialpha-1) + &
1236	weight_b * turb_cl_sel2(ialpha-1) ) +&
1237	( alpha_attack_i - &
1238	alpha_attack_tab(ialpha-1) ) / &
1239	( alpha_attack_tab(ialpha) - &
1240	alpha_attack_tab(ialpha-1) ) * &
1241	( weight_a * turb_cl_sel1(ialpha) + &
1242	weight_b * turb_cl_sel2(ialpha) )
1243	turb_cd_tab(iialpha,iir) = ( alpha_attack_tab(ialpha) - &
1244	alpha_attack_i ) / &
1245	( alpha_attack_tab(ialpha) - &
1246	alpha_attack_tab(ialpha-1) ) * &
1247	( weight_a * turb_cd_sel1(ialpha-1) + &
1248	weight_b * turb_cd_sel2(ialpha-1) ) +&
1249	( alpha_attack_i - &
1250	alpha_attack_tab(ialpha-1) ) / &
1251	( alpha_attack_tab(ialpha) - &
1252	alpha_attack_tab(ialpha-1) ) * &
1253	( weight_a * turb_cd_sel1(ialpha) + &
1254	weight_b * turb_cd_sel2(ialpha) )
1255
1256	ENDDO ! end loop over angles of attack
1257
1258	ENDDO ! end loop over radius
1259
1260	END SUBROUTINE wtm_read_blade_tables
1261
1262
1263	!------------------------------------------------------------------------------!
1264	! Description:
1265	! ------------
1266	!> The projection matrix for the coordinate system of therotor disc in respect
1267	!> to the yaw and tilt angle of the rotor is calculated
1268	!------------------------------------------------------------------------------!
1269	SUBROUTINE wtm_rotate_rotor( inot )
1270
1271
1272	IMPLICIT NONE
1273
1274	INTEGER(iwp) :: inot
1275	!
1276	!-- Calculation of the rotation matrix for the application of the tilt to
1277	!-- the rotors
1278	rot_eigen_rad(1) = SIN( phi_yaw(inot) ) ! x-component of the radial eigenvector
1279	rot_eigen_rad(2) = COS( phi_yaw(inot) ) ! y-component of the radial eigenvector
1280	rot_eigen_rad(3) = 0.0_wp ! z-component of the radial eigenvector
1281
1282	rot_eigen_azi(1) = 0.0_wp ! x-component of the azimuth eigenvector
1283	rot_eigen_azi(2) = 0.0_wp ! y-component of the azimuth eigenvector
1284	rot_eigen_azi(3) = 1.0_wp ! z-component of the azimuth eigenvector
1285
1286	rot_eigen_nor(1) = COS( phi_yaw(inot) ) ! x-component of the normal eigenvector
1287	rot_eigen_nor(2) = -SIN( phi_yaw(inot) ) ! y-component of the normal eigenvector
1288	rot_eigen_nor(3) = 0.0_wp ! z-component of the normal eigenvector
1289
1290	!
1291	!-- Calculation of the coordinate transformation matrix to apply a tilt to
1292	!-- the rotor. If tilt = 0, rot_coord_trans is a unit matrix.
1293
1294	rot_coord_trans(inot,1,1) = rot_eigen_rad(1)*2 &
1295	( 1.0_wp - COS( tilt ) ) + COS( tilt )
1296	rot_coord_trans(inot,1,2) = rot_eigen_rad(1) * rot_eigen_rad(2) * &
1297	( 1.0_wp - COS( tilt ) ) - &
1298	rot_eigen_rad(3) * SIN( tilt )
1299	rot_coord_trans(inot,1,3) = rot_eigen_rad(1) * rot_eigen_rad(3) * &
1300	( 1.0_wp - COS( tilt ) ) + &
1301	rot_eigen_rad(2) * SIN( tilt )
1302	rot_coord_trans(inot,2,1) = rot_eigen_rad(2) * rot_eigen_rad(1) * &
1303	( 1.0_wp - COS( tilt ) ) + &
1304	rot_eigen_rad(3) * SIN( tilt )
1305	rot_coord_trans(inot,2,2) = rot_eigen_rad(2)*2 &
1306	( 1.0_wp - COS( tilt ) ) + COS( tilt )
1307	rot_coord_trans(inot,2,3) = rot_eigen_rad(2) * rot_eigen_rad(3) * &
1308	( 1.0_wp - COS( tilt ) ) - &
1309	rot_eigen_rad(1) * SIN( tilt )
1310	rot_coord_trans(inot,3,1) = rot_eigen_rad(3) * rot_eigen_rad(1) * &
1311	( 1.0_wp - COS( tilt ) ) - &
1312	rot_eigen_rad(2) * SIN( tilt )
1313	rot_coord_trans(inot,3,2) = rot_eigen_rad(3) * rot_eigen_rad(2) * &
1314	( 1.0_wp - COS( tilt ) ) + &
1315	rot_eigen_rad(1) * SIN( tilt )
1316	rot_coord_trans(inot,3,3) = rot_eigen_rad(3)*2 &
1317	( 1.0_wp - COS( tilt ) ) + COS( tilt )
1318
1319	!
1320	!-- Vectors for the Transformation of forces from the rotor's spheric
1321	!-- coordinate system to the cartesian coordinate system
1322	rotx(inot,:) = MATMUL( rot_coord_trans(inot,:,:), rot_eigen_nor )
1323	roty(inot,:) = MATMUL( rot_coord_trans(inot,:,:), rot_eigen_rad )
1324	rotz(inot,:) = MATMUL( rot_coord_trans(inot,:,:), rot_eigen_azi )
1325
1326	END SUBROUTINE wtm_rotate_rotor
1327
1328
1329	!------------------------------------------------------------------------------!
1330	! Description:
1331	! ------------
1332	!> Calculation of the forces generated by the wind turbine
1333	!------------------------------------------------------------------------------!
1334	SUBROUTINE wtm_forces
1335
1336
1337	IMPLICIT NONE
1338
1339	CHARACTER (LEN=2) :: turbine_id
1340
1341	INTEGER(iwp) :: i, j, k !< loop indices
1342	INTEGER(iwp) :: inot !< turbine loop index (turbine id)
1343	INTEGER(iwp) :: iialpha, iir !<
1344	INTEGER(iwp) :: rseg, rseg_int !<
1345	INTEGER(iwp) :: ring, ring_int !<
1346	INTEGER(iwp) :: ii, jj, kk !<
1347
1348	REAL(wp) :: sin_rot, cos_rot !<
1349	REAL(wp) :: sin_yaw, cos_yaw !<
1350
1351	REAL(wp) :: aa, bb, cc, dd !< interpolation distances
1352	REAL(wp) :: gg !< interpolation volume var
1353
1354	REAL(wp) :: dist_u_3d, dist_v_3d, dist_w_3d !< smearing distances
1355
1356
1357	!
1358	! Variables for pitch control
1359	REAL(wp) :: torque_max=0.0_wp
1360	LOGICAL :: pitch_sw=.FALSE.
1361
1362	INTEGER(iwp), DIMENSION(1) :: lct=0
1363	REAL(wp), DIMENSION(1) :: rad_d=0.0_wp
1364
1365
1366	CALL cpu_log( log_point_s(61), 'wtm_forces', 'start' )
1367
1368
1369	IF ( simulated_time >= time_turbine_on ) THEN
1370
1371	!
1372	!-- Set forces to zero for each new time step:
1373	thrust(:,:,:) = 0.0_wp
1374	torque_y(:,:,:) = 0.0_wp
1375	torque_z(:,:,:) = 0.0_wp
1376	torque_total(:) = 0.0_wp
1377	rot_tend_x(:,:,:) = 0.0_wp
1378	rot_tend_y(:,:,:) = 0.0_wp
1379	rot_tend_z(:,:,:) = 0.0_wp
1380	thrust_rotor(:) = 0.0_wp
1381	!
1382	!-- Loop over number of turbines:
1383	DO inot = 1, nturbines
1384
1385	cos_yaw = COS(phi_yaw(inot))
1386	sin_yaw = SIN(phi_yaw(inot))
1387	!
1388	!-- Loop over rings of each turbine:
1389	DO ring = 1, nrings(inot)
1390
1391	thrust_seg(:) = 0.0_wp
1392	torque_seg_y(:) = 0.0_wp
1393	torque_seg_z(:) = 0.0_wp
1394	!
1395	!-- Determine distance between each ring (center) and the hub:
1396	cur_r = (ring - 0.5_wp) * delta_r(inot)
1397
1398	!
1399	!-- Loop over segments of each ring of each turbine:
1400	DO rseg = 1, nsegs(ring,inot)
1401	!
1402	!-- !-----------------------------------------------------------!
1403	!-- !-- Determine coordinates of the ring segments --!
1404	!-- !-----------------------------------------------------------!
1405	!
1406	!-- Determine angle of ring segment towards zero degree angle of
1407	!-- rotor system (at zero degree rotor direction vectors aligned
1408	!-- with y-axis):
1409	phi_rotor = rseg * 2.0_wp * pi / nsegs(ring,inot)
1410	cos_rot = COS( phi_rotor )
1411	sin_rot = SIN( phi_rotor )
1412
1413	!-- Now the direction vectors can be determined with respect to
1414	!-- the yaw and tilt angle:
1415	re(1) = cos_rot * sin_yaw
1416	re(2) = cos_rot * cos_yaw
1417	re(3) = sin_rot
1418
1419	rote = MATMUL( rot_coord_trans(inot,:,:), re )
1420	!
1421	!-- Coordinates of the single segments (center points):
1422	rbx(ring,rseg) = rcx(inot) + cur_r * rote(1)
1423	rby(ring,rseg) = rcy(inot) + cur_r * rote(2)
1424	rbz(ring,rseg) = rcz(inot) + cur_r * rote(3)
1425
1426	!-- !-----------------------------------------------------------!
1427	!-- !-- Interpolation of the velocity components from the --!
1428	!-- !-- cartesian grid point to the coordinates of each ring --!
1429	!-- !-- segment (follows a method used in the particle model) --!
1430	!-- !-----------------------------------------------------------!
1431
1432	u_int(inot,ring,rseg) = 0.0_wp
1433	u_int_1_l(inot,ring,rseg) = 0.0_wp
1434
1435	v_int(inot,ring,rseg) = 0.0_wp
1436	v_int_1_l(inot,ring,rseg) = 0.0_wp
1437
1438	w_int(inot,ring,rseg) = 0.0_wp
1439	w_int_1_l(inot,ring,rseg) = 0.0_wp
1440
1441	!
1442	!-- Interpolation of the u-component:
1443
1444	ii = rbx(ring,rseg) * ddx
1445	jj = ( rby(ring,rseg) - 0.5_wp * dy ) * ddy
1446	kk = ( rbz(ring,rseg) - 0.5_wp * dz ) / dz
1447	!
1448	!-- Interpolate only if all required information is available on
1449	!-- the current PE:
1450	IF ( ( ii >= nxl ) .AND. ( ii <= nxr ) ) THEN
1451	IF ( ( jj >= nys ) .AND. ( jj <= nyn ) ) THEN
1452
1453	aa = ( ( ii + 1 ) * dx - rbx(ring,rseg) ) * &
1454	( ( jj + 1 + 0.5_wp ) * dy - rby(ring,rseg) )
1455	bb = ( rbx(ring,rseg) - ii * dx ) * &
1456	( ( jj + 1 + 0.5_wp ) * dy - rby(ring,rseg) )
1457	cc = ( ( ii+1 ) * dx - rbx(ring,rseg) ) * &
1458	( rby(ring,rseg) - ( jj + 0.5_wp ) * dy )
1459	dd = ( rbx(ring,rseg) - ii * dx ) * &
1460	( rby(ring,rseg) - ( jj + 0.5_wp ) * dy )
1461	gg = dx * dy
1462
1463	u_int_l = ( aa * u(kk,jj,ii) + &
1464	bb * u(kk,jj,ii+1) + &
1465	cc * u(kk,jj+1,ii) + &
1466	dd * u(kk,jj+1,ii+1) &
1467	) / gg
1468
1469	u_int_u = ( aa * u(kk+1,jj,ii) + &
1470	bb * u(kk+1,jj,ii+1) + &
1471	cc * u(kk+1,jj+1,ii) + &
1472	dd * u(kk+1,jj+1,ii+1) &
1473	) / gg
1474
1475	u_int_1_l(inot,ring,rseg) = u_int_l + &
1476	( rbz(ring,rseg) - zu(kk) ) / dz * &
1477	( u_int_u - u_int_l )
1478
1479	ELSE
1480	u_int_1_l(inot,ring,rseg) = 0.0_wp
1481	ENDIF
1482	ELSE
1483	u_int_1_l(inot,ring,rseg) = 0.0_wp
1484	ENDIF
1485
1486
1487	!
1488	!-- Interpolation of the v-component:
1489	ii = ( rbx(ring,rseg) - 0.5_wp * dx ) * ddx
1490	jj = rby(ring,rseg) * ddy
1491	kk = ( rbz(ring,rseg) + 0.5_wp * dz ) / dz
1492	!
1493	!-- Interpolate only if all required information is available on
1494	!-- the current PE:
1495	IF ( ( ii >= nxl ) .AND. ( ii <= nxr ) ) THEN
1496	IF ( ( jj >= nys ) .AND. ( jj <= nyn ) ) THEN
1497
1498	aa = ( ( ii + 1 + 0.5_wp ) * dx - rbx(ring,rseg) ) * &
1499	( ( jj + 1 ) * dy - rby(ring,rseg) )
1500	bb = ( rbx(ring,rseg) - ( ii + 0.5_wp ) * dx ) * &
1501	( ( jj + 1 ) * dy - rby(ring,rseg) )
1502	cc = ( ( ii + 1 + 0.5_wp ) * dx - rbx(ring,rseg) ) * &
1503	( rby(ring,rseg) - jj * dy )
1504	dd = ( rbx(ring,rseg) - ( ii + 0.5_wp ) * dx ) * &
1505	( rby(ring,rseg) - jj * dy )
1506	gg = dx * dy
1507
1508	v_int_l = ( aa * v(kk,jj,ii) + &
1509	bb * v(kk,jj,ii+1) + &
1510	cc * v(kk,jj+1,ii) + &
1511	dd * v(kk,jj+1,ii+1) &
1512	) / gg
1513
1514	v_int_u = ( aa * v(kk+1,jj,ii) + &
1515	bb * v(kk+1,jj,ii+1) + &
1516	cc * v(kk+1,jj+1,ii) + &
1517	dd * v(kk+1,jj+1,ii+1) &
1518	) / gg
1519
1520	v_int_1_l(inot,ring,rseg) = v_int_l + &
1521	( rbz(ring,rseg) - zu(kk) ) / dz * &
1522	( v_int_u - v_int_l )
1523
1524	ELSE
1525	v_int_1_l(inot,ring,rseg) = 0.0_wp
1526	ENDIF
1527	ELSE
1528	v_int_1_l(inot,ring,rseg) = 0.0_wp
1529	ENDIF
1530
1531
1532	!
1533	!-- Interpolation of the w-component:
1534	ii = ( rbx(ring,rseg) - 0.5_wp * dx ) * ddx
1535	jj = ( rby(ring,rseg) - 0.5_wp * dy ) * ddy
1536	kk = rbz(ring,rseg) / dz
1537	!
1538	!-- Interpolate only if all required information is available on
1539	!-- the current PE:
1540	IF ( ( ii >= nxl ) .AND. ( ii <= nxr ) ) THEN
1541	IF ( ( jj >= nys ) .AND. ( jj <= nyn ) ) THEN
1542
1543	aa = ( ( ii + 1 + 0.5_wp ) * dx - rbx(ring,rseg) ) * &
1544	( ( jj + 1 + 0.5_wp ) * dy - rby(ring,rseg) )
1545	bb = ( rbx(ring,rseg) - ( ii + 0.5_wp ) * dx ) * &
1546	( ( jj + 1 + 0.5_wp ) * dy - rby(ring,rseg) )
1547	cc = ( ( ii + 1 + 0.5_wp ) * dx - rbx(ring,rseg) ) * &
1548	( rby(ring,rseg) - ( jj + 0.5_wp ) * dy )
1549	dd = ( rbx(ring,rseg) - ( ii + 0.5_wp ) * dx ) * &
1550	( rby(ring,rseg) - ( jj + 0.5_wp ) * dy )
1551	gg = dx * dy
1552
1553	w_int_l = ( aa * w(kk,jj,ii) + &
1554	bb * w(kk,jj,ii+1) + &
1555	cc * w(kk,jj+1,ii) + &
1556	dd * w(kk,jj+1,ii+1) &
1557	) / gg
1558
1559	w_int_u = ( aa * w(kk+1,jj,ii) + &
1560	bb * w(kk+1,jj,ii+1) + &
1561	cc * w(kk+1,jj+1,ii) + &
1562	dd * w(kk+1,jj+1,ii+1) &
1563	) / gg
1564
1565	w_int_1_l(inot,ring,rseg) = w_int_l + &
1566	( rbz(ring,rseg) - zw(kk) ) / dz * &
1567	( w_int_u - w_int_l )
1568	ELSE
1569	w_int_1_l(inot,ring,rseg) = 0.0_wp
1570	ENDIF
1571	ELSE
1572	w_int_1_l(inot,ring,rseg) = 0.0_wp
1573	ENDIF
1574
1575	ENDDO
1576	ENDDO
1577
1578	ENDDO
1579
1580	!
1581	!-- Exchange between PEs (information required on each PE):
1582	#if defined( __parallel )
1583	CALL MPI_ALLREDUCE( u_int_1_l, u_int, nturbines * MAXVAL(nrings) * &
1584	MAXVAL(nsegs), MPI_REAL, MPI_SUM, comm2d, ierr )
1585	CALL MPI_ALLREDUCE( v_int_1_l, v_int, nturbines * MAXVAL(nrings) * &
1586	MAXVAL(nsegs), MPI_REAL, MPI_SUM, comm2d, ierr )
1587	CALL MPI_ALLREDUCE( w_int_1_l, w_int, nturbines * MAXVAL(nrings) * &
1588	MAXVAL(nsegs), MPI_REAL, MPI_SUM, comm2d, ierr )
1589	#else
1590	u_int = u_int_1_l
1591	v_int = v_int_1_l
1592	w_int = w_int_1_l
1593	#endif
1594
1595
1596	!
1597	!-- Loop over number of turbines:
1598
1599	DO inot = 1, nturbines
1600	pit_loop: DO
1601
1602	IF ( pitch_sw ) THEN
1603	torque_total(inot) = 0.0_wp
1604	thrust_rotor(inot) = 0.0_wp
1605	pitch_add(inot) = pitch_add(inot) + 0.25_wp
1606	! IF ( myid == 0 ) PRINT*, 'Pitch', inot, pitch_add(inot)
1607	ELSE
1608	cos_yaw = COS(phi_yaw(inot))
1609	sin_yaw = SIN(phi_yaw(inot))
1610	IF ( pitch_control ) THEN
1611	pitch_add(inot) = MAX(pitch_add_old(inot) - pitch_rate * &
1612	dt_3d , 0.0_wp )
1613	ENDIF
1614	ENDIF
1615
1616	!
1617	!-- Loop over rings of each turbine:
1618	DO ring = 1, nrings(inot)
1619	!
1620	!-- Determine distance between each ring (center) and the hub:
1621	cur_r = (ring - 0.5_wp) * delta_r(inot)
1622	!
1623	!-- Loop over segments of each ring of each turbine:
1624	DO rseg = 1, nsegs(ring,inot)
1625	!
1626	!-- Determine angle of ring segment towards zero degree angle of
1627	!-- rotor system (at zero degree rotor direction vectors aligned
1628	!-- with y-axis):
1629	phi_rotor = rseg * 2.0_wp * pi / nsegs(ring,inot)
1630	cos_rot = COS(phi_rotor)
1631	sin_rot = SIN(phi_rotor)
1632	!
1633	!-- Now the direction vectors can be determined with respect to
1634	!-- the yaw and tilt angle:
1635	re(1) = cos_rot * sin_yaw
1636	re(2) = cos_rot * cos_yaw
1637	re(3) = sin_rot
1638
1639	! The current unit vector in azimuthal direction:
1640	rea(1) = - sin_rot * sin_yaw
1641	rea(2) = - sin_rot * cos_yaw
1642	rea(3) = cos_rot
1643
1644	!
1645	!-- To respect the yawing angle for the calculations of
1646	!-- velocities and forces the unit vectors perpendicular to the
1647	!-- rotor area in direction of the positive yaw angle are defined:
1648	ren(1) = cos_yaw
1649	ren(2) = - sin_yaw
1650	ren(3) = 0.0_wp
1651	!
1652	!-- Multiplication with the coordinate transformation matrix
1653	!-- gives the final unit vector with consideration of the rotor
1654	!-- tilt:
1655	rote = MATMUL( rot_coord_trans(inot,:,:), re )
1656	rota = MATMUL( rot_coord_trans(inot,:,:), rea )
1657	rotn = MATMUL( rot_coord_trans(inot,:,:), ren )
1658	!
1659	!-- Coordinates of the single segments (center points):
1660	rbx(ring,rseg) = rcx(inot) + cur_r * rote(1)
1661
1662	rby(ring,rseg) = rcy(inot) + cur_r * rote(2)
1663
1664	rbz(ring,rseg) = rcz(inot) + cur_r * rote(3)
1665
1666	!
1667	!-- !-----------------------------------------------------------!
1668	!-- !-- Calculation of various angles and relative velocities --!
1669	!-- !-----------------------------------------------------------!
1670	!
1671	!-- In the following the 3D-velocity field is projected its
1672	!-- components perpedicular and parallel to the rotor area
1673	!-- The calculation of forces will be done in the rotor-
1674	!-- coordinates y' and z.
1675	!-- The yaw angle will be reintroduced when the force is applied
1676	!-- on the hydrodynamic equations
1677	!
1678	!-- Projection of the xy-velocities relative to the rotor area
1679	!
1680	!-- Velocity perpendicular to the rotor area:
1681	u_rot = u_int(inot,ring,rseg)*rotn(1) + &
1682	v_int(inot,ring,rseg)*rotn(2) + &
1683	w_int(inot,ring,rseg)*rotn(3)
1684	!
1685	!-- Projection of the 3D-velocity vector in the azimuthal
1686	!-- direction:
1687	vtheta(rseg) = rota(1) * u_int(inot,ring,rseg) + &
1688	rota(2) * v_int(inot,ring,rseg) + &
1689	rota(3) * w_int(inot,ring,rseg)
1690	!
1691	!-- Determination of the angle phi_rel between the rotor plane
1692	!-- and the direction of the flow relative to the rotor:
1693
1694	phi_rel(rseg) = ATAN( u_rot / &
1695	( omega_rot(inot) * cur_r - &
1696	vtheta(rseg) ) )
1697
1698	!
1699	!-- Interpolation of the local pitch angle from tabulated values
1700	!-- to the current radial position:
1701
1702	lct=minloc(ABS(cur_r-lrd))
1703	rad_d=cur_r-lrd(lct)
1704
1705	IF (cur_r == 0.0_wp) THEN
1706	alpha_attack(rseg) = 0.0_wp
1707	ELSE IF (cur_r >= lrd(size(ard))) THEN
1708	alpha_attack(rseg) = ( ard(size(ard)) + &
1709	ard(size(ard)-1) ) / 2.0_wp
1710	ELSE
1711	alpha_attack(rseg) = ( ard(lct(1)) * &
1712	( ( lrd(lct(1)+1) - cur_r ) / &
1713	( lrd(lct(1)+1) - lrd(lct(1)) ) &
1714	) ) + ( ard(lct(1)+1) * &
1715	( ( cur_r - lrd(lct(1)) ) / &
1716	( lrd(lct(1)+1) - lrd(lct(1)) ) ) )
1717	ENDIF
1718
1719	!
1720	!-- In Fortran radian instead of degree is used as unit for all
1721	!-- angles. Therefore, a transformation from angles given in
1722	!-- degree to angles given in radian is necessary here:
1723	alpha_attack(rseg) = alpha_attack(rseg) * &
1724	( (2.0_wp*pi) / 360.0_wp )
1725	!
1726	!-- Substraction of the local pitch angle to obtain the local
1727	!-- angle of attack:
1728	alpha_attack(rseg) = phi_rel(rseg) - alpha_attack(rseg)
1729	!
1730	!-- Preliminary transformation back from angles given in radian
1731	!-- to angles given in degree:
1732	alpha_attack(rseg) = alpha_attack(rseg) * &
1733	( 360.0_wp / (2.0_wp*pi) )
1734	!
1735	!-- Correct with collective pitch angle:
1736	alpha_attack = alpha_attack + pitch_add(inot)
1737
1738	!
1739	!-- Determination of the magnitude of the flow velocity relative
1740	!-- to the rotor:
1741	vrel(rseg) = SQRT( u_rot**2 + &
1742	( omega_rot(inot) * cur_r - &
1743	vtheta(rseg) )**2 )
1744
1745	!
1746	!-- !-----------------------------------------------------------!
1747	!-- !-- Interpolation of chord as well as lift and drag --!
1748	!-- !-- coefficients from tabulated values --!
1749	!-- !-----------------------------------------------------------!
1750
1751	!
1752	!-- Interpolation of the chord_length from tabulated values to
1753	!-- the current radial position:
1754
1755	IF (cur_r == 0.0_wp) THEN
1756	chord(rseg) = 0.0_wp
1757	ELSE IF (cur_r >= lrd(size(crd))) THEN
1758	chord(rseg) = (crd(size(crd)) + ard(size(crd)-1)) / 2.0_wp
1759	ELSE
1760	chord(rseg) = ( crd(lct(1)) * &
1761	( ( lrd(lct(1)+1) - cur_r ) / &
1762	( lrd(lct(1)+1) - lrd(lct(1)) ) ) ) + &
1763	( crd(lct(1)+1) * &
1764	( ( cur_r-lrd(lct(1)) ) / &
1765	( lrd(lct(1)+1) - lrd(lct(1)) ) ) )
1766	ENDIF
1767
1768	!
1769	!-- Determine index of current angle of attack, needed for
1770	!-- finding the appropriate interpolated values of the lift and
1771	!-- drag coefficients (-180.0 degrees = 0, +180.0 degrees = 36000,
1772	!-- so one index every 0.01 degrees):
1773	iialpha = CEILING( ( alpha_attack(rseg) + 180.0_wp ) &
1774	* ( 1.0_wp / accu_cl_cd_tab ) )
1775	!
1776	!-- Determine index of current radial position, needed for
1777	!-- finding the appropriate interpolated values of the lift and
1778	!-- drag coefficients (one index every 0.1 m):
1779	iir = CEILING( cur_r * 10.0_wp )
1780	!
1781	!-- Read in interpolated values of the lift and drag coefficients
1782	!-- for the current radial position and angle of attack:
1783	turb_cl(rseg) = turb_cl_tab(iialpha,iir)
1784	turb_cd(rseg) = turb_cd_tab(iialpha,iir)
1785
1786	!
1787	!-- Final transformation back from angles given in degree to
1788	!-- angles given in radian:
1789	alpha_attack(rseg) = alpha_attack(rseg) * &
1790	( (2.0_wp*pi) / 360.0_wp )
1791
1792	!
1793	!-- !-----------------------------------------------------!
1794	!-- !-- Calculation of the forces --!
1795	!-- !-----------------------------------------------------!
1796
1797	!
1798	!-- Calculate the pre_factor for the thrust and torque forces:
1799
1800	pre_factor = 0.5_wp * (vrel(rseg)*2) 3.0_wp * &
1801	chord(rseg) * delta_r(inot) / nsegs(ring,inot)
1802
1803	!
1804	!-- Calculate the thrust force (x-component of the total force)
1805	!-- for each ring segment:
1806	thrust_seg(rseg) = pre_factor * &
1807	( turb_cl(rseg) * COS(phi_rel(rseg)) + &
1808	turb_cd(rseg) * SIN(phi_rel(rseg)) )
1809
1810	!
1811	!-- Determination of the second of the additional forces acting
1812	!-- on the flow in the azimuthal direction: force vector as basis
1813	!-- for torque (torque itself would be the vector product of the
1814	!-- radius vector and the force vector):
1815	torque_seg = pre_factor * &
1816	( turb_cl(rseg) * SIN(phi_rel(rseg)) - &
1817	turb_cd(rseg) * COS(phi_rel(rseg)) )
1818	!
1819	!-- Decomposition of the force vector into two parts:
1820	!-- One acting along the y-direction and one acting along the
1821	!-- z-direction of the rotor coordinate system:
1822
1823	torque_seg_y(rseg) = -torque_seg * sin_rot
1824	torque_seg_z(rseg) = torque_seg * cos_rot
1825
1826	!
1827	!-- Add the segment thrust to the thrust of the whole rotor
1828	thrust_rotor(inot) = thrust_rotor(inot) + &
1829	thrust_seg(rseg)
1830
1831
1832	torque_total(inot) = torque_total(inot) + (torque_seg * cur_r)
1833
1834	ENDDO !-- end of loop over ring segments
1835
1836	!
1837	!-- Restore the forces into arrays containing all the segments of
1838	!-- each ring:
1839	thrust_ring(ring,:) = thrust_seg(:)
1840	torque_ring_y(ring,:) = torque_seg_y(:)
1841	torque_ring_z(ring,:) = torque_seg_z(:)
1842
1843
1844	ENDDO !-- end of loop over rings
1845
1846
1847	CALL cpu_log( log_point_s(62), 'wtm_controller', 'start' )
1848
1849
1850	IF ( speed_control ) THEN
1851	!
1852	!-- Calculation of the current generator speed for rotor speed control
1853
1854	!
1855	!-- The acceleration of the rotor speed is calculated from
1856	!-- the force balance of the accelerating torque
1857	!-- and the torque of the rotating rotor and generator
1858	om_rate = ( torque_total(inot) * air_dens * gear_eff - &
1859	gear_ratio * torque_gen_old(inot) ) / &
1860	( inertia_rot + &
1861	gear_ratio * gear_ratio * inertia_gen ) * dt_3d
1862
1863	!
1864	!-- The generator speed is given by the product of gear gear_ratio
1865	!-- and rotor speed
1866	omega_gen(inot) = gear_ratio * ( omega_rot(inot) + om_rate )
1867
1868	ENDIF
1869
1870	IF ( pitch_control ) THEN
1871
1872	!
1873	!-- If the current generator speed is above rated, the pitch is not
1874	!-- saturated and the change from the last time step is within the
1875	!-- maximum pitch rate, then the pitch loop is repeated with a pitch
1876	!-- gain
1877	IF ( ( omega_gen(inot) > rated_genspeed ) .AND. &
1878	( pitch_add(inot) < 25.0_wp ) .AND. &
1879	( pitch_add(inot) < pitch_add_old(inot) + &
1880	pitch_rate * dt_3d ) ) THEN
1881	pitch_sw = .TRUE.
1882	!
1883	!-- Go back to beginning of pit_loop
1884	CYCLE pit_loop
1885	ENDIF
1886
1887	!
1888	!-- The current pitch is saved for the next time step
1889	pitch_add_old(inot) = pitch_add(inot)
1890	pitch_sw = .FALSE.
1891	ENDIF
1892	EXIT pit_loop
1893	ENDDO pit_loop ! Recursive pitch control loop
1894
1895
1896	!
1897	!-- Call the rotor speed controller
1898
1899	IF ( speed_control ) THEN
1900	!
1901	!-- Find processor at i_hub, j_hub
1902	IF ( ( nxl <= i_hub(inot) ) .AND. ( nxr >= i_hub(inot) ) ) &
1903	THEN
1904	IF ( ( nys <= j_hub(inot) ) .AND. ( nyn >= j_hub(inot) ) )&
1905	THEN
1906	CALL wtm_speed_control( inot )
1907	ENDIF
1908	ENDIF
1909
1910	ENDIF
1911
1912
1913	CALL cpu_log( log_point_s(62), 'wtm_controller', 'stop' )
1914
1915	CALL cpu_log( log_point_s(63), 'wtm_smearing', 'start' )
1916
1917
1918	!-- !-----------------------------------------------------------------!
1919	!-- !-- Regularization kernel --!
1920	!-- !-- Smearing of the forces and interpolation to cartesian grid --!
1921	!-- !-----------------------------------------------------------------!
1922	!
1923	!-- The aerodynamic blade forces need to be distributed smoothly on
1924	!-- several mesh points in order to avoid singular behaviour
1925	!
1926	!-- Summation over sum of weighted forces. The weighting factor
1927	!-- (calculated in user_init) includes information on the distance
1928	!-- between the center of the grid cell and the rotor segment under
1929	!-- consideration
1930	!
1931	!-- To save computing time, apply smearing only for the relevant part
1932	!-- of the model domain:
1933	!
1934	!--
1935	!-- Calculation of the boundaries:
1936	i_smear(inot) = CEILING( ( rr(inot) * ABS( roty(inot,1) ) + &
1937	eps_min ) / dx )
1938	j_smear(inot) = CEILING( ( rr(inot) * ABS( roty(inot,2) ) + &
1939	eps_min ) / dy )
1940
1941	DO i = MAX( nxl, i_hub(inot) - i_smear(inot) ), &
1942	MIN( nxr, i_hub(inot) + i_smear(inot) )
1943	DO j = MAX( nys, j_hub(inot) - j_smear(inot) ), &
1944	MIN( nyn, j_hub(inot) + j_smear(inot) )
1945	DO k = MAX( nzb_u_inner(j,i)+1, k_hub(inot) - k_smear(inot) ), &
1946	k_hub(inot) + k_smear(inot)
1947	DO ring = 1, nrings(inot)
1948	DO rseg = 1, nsegs(ring,inot)
1949	!
1950	!-- Determine the square of the distance between the
1951	!-- current grid point and each rotor area segment:
1952	dist_u_3d = ( i * dx - rbx(ring,rseg) )**2 + &
1953	( j * dy + 0.5_wp * dy - rby(ring,rseg) )**2 + &
1954	( k * dz - 0.5_wp * dz - rbz(ring,rseg) )**2
1955	dist_v_3d = ( i * dx + 0.5_wp * dx - rbx(ring,rseg) )**2 + &
1956	( j * dy - rby(ring,rseg) )**2 + &
1957	( k * dz - 0.5_wp * dz - rbz(ring,rseg) )**2
1958	dist_w_3d = ( i * dx + 0.5_wp * dx - rbx(ring,rseg) )**2 + &
1959	( j * dy + 0.5_wp * dy - rby(ring,rseg) )**2 + &
1960	( k * dz - rbz(ring,rseg) )**2
1961
1962	!
1963	!-- 3D-smearing of the forces with a polynomial function
1964	!-- (much faster than the old Gaussian function), using
1965	!-- some parameters that have been calculated in user_init.
1966	!-- The function is only similar to Gaussian function for
1967	!-- squared distances <= eps_min2:
1968	IF ( dist_u_3d <= eps_min2 ) THEN
1969	thrust(k,j,i) = thrust(k,j,i) + &
1970	thrust_ring(ring,rseg) * &
1971	( ( pol_a * dist_u_3d - pol_b ) * &
1972	dist_u_3d + 1.0_wp ) * eps_factor
1973	ENDIF
1974	IF ( dist_v_3d <= eps_min2 ) THEN
1975	torque_y(k,j,i) = torque_y(k,j,i) + &
1976	torque_ring_y(ring,rseg) * &
1977	( ( pol_a * dist_v_3d - pol_b ) *&
1978	dist_v_3d + 1.0_wp ) * eps_factor
1979	ENDIF
1980	IF ( dist_w_3d <= eps_min2 ) THEN
1981	torque_z(k,j,i) = torque_z(k,j,i) + &
1982	torque_ring_z(ring,rseg) * &
1983	( ( pol_a * dist_w_3d - pol_b ) *&
1984	dist_w_3d + 1.0_wp ) * eps_factor
1985	ENDIF
1986
1987	ENDDO ! End of loop over rseg
1988	ENDDO ! End of loop over ring
1989
1990	!
1991	!-- Rotation of force components:
1992	rot_tend_x(k,j,i) = rot_tend_x(k,j,i) + &
1993	thrust(k,j,i)*rotx(inot,1) + &
1994	torque_y(k,j,i)*roty(inot,1) + &
1995	torque_z(k,j,i)*rotz(inot,1)
1996
1997	rot_tend_y(k,j,i) = rot_tend_y(k,j,i) + &
1998	thrust(k,j,i)*rotx(inot,2) + &
1999	torque_y(k,j,i)*roty(inot,2) + &
2000	torque_z(k,j,i)*rotz(inot,2)
2001
2002	rot_tend_z(k,j,i) = rot_tend_z(k,j,i) + &
2003	thrust(k,j,i)*rotx(inot,3) + &
2004	torque_y(k,j,i)*roty(inot,3) + &
2005	torque_z(k,j,i)*rotz(inot,3)
2006
2007	ENDDO ! End of loop over k
2008	ENDDO ! End of loop over j
2009	ENDDO ! End of loop over i
2010
2011	CALL cpu_log( log_point_s(63), 'wtm_smearing', 'stop' )
2012
2013	ENDDO !-- end of loop over turbines
2014
2015
2016	IF ( yaw_control ) THEN
2017	!
2018	!-- Allocate arrays for yaw control at first call
2019	!-- Can't be allocated before dt_3d is set
2020	IF ( start_up ) THEN
2021	WDLON = NINT( 30.0_wp / dt_3d ) ! 30s running mean array
2022	ALLOCATE( wd30(1:nturbines,1:WDLON) )
2023	wd30 = 999.0_wp ! Set to dummy value
2024	ALLOCATE( wd30_l(1:WDLON) )
2025
2026	WDSHO = NINT( 2.0_wp / dt_3d ) ! 2s running mean array
2027	ALLOCATE( wd2(1:nturbines,1:WDSHO) )
2028	wd2 = 999.0_wp ! Set to dummy value
2029	ALLOCATE( wd2_l(1:WDSHO) )
2030	start_up = .FALSE.
2031	ENDIF
2032
2033	!
2034	!-- Calculate the inflow wind speed
2035	!--
2036	!-- Loop over number of turbines:
2037	DO inot = 1, nturbines
2038	!
2039	!-- Find processor at i_hub, j_hub
2040	IF ( ( nxl <= i_hub(inot) ) .AND. ( nxr >= i_hub(inot) ) ) &
2041	THEN
2042	IF ( ( nys <= j_hub(inot) ) .AND. ( nyn >= j_hub(inot) ) )&
2043	THEN
2044
2045	u_inflow_l(inot) = u(k_hub(inot),j_hub(inot),i_hub(inot))
2046
2047	wdir_l(inot) = -1.0_wp * ATAN2( &
2048	0.5_wp * ( v(k_hub(inot),j_hub(inot),i_hub(inot)+1) + &
2049	v(k_hub(inot),j_hub(inot),i_hub(inot)) ) , &
2050	0.5_wp * ( u(k_hub(inot),j_hub(inot)+1,i_hub(inot)) + &
2051	u(k_hub(inot),j_hub(inot),i_hub(inot)) ) )
2052
2053	CALL wtm_yawcontrol( inot )
2054
2055	phi_yaw_l(inot) = phi_yaw(inot)
2056
2057	ENDIF
2058	ENDIF
2059
2060	ENDDO !-- end of loop over turbines
2061
2062	!
2063	!-- Transfer of information to the other cpus
2064	#if defined( __parallel )
2065	CALL MPI_ALLREDUCE( u_inflow_l, u_inflow, nturbines, MPI_REAL, &
2066	MPI_SUM, comm2d, ierr )
2067	CALL MPI_ALLREDUCE( wdir_l, wdir, nturbines, MPI_REAL, MPI_SUM, &
2068	comm2d, ierr )
2069	CALL MPI_ALLREDUCE( phi_yaw_l, phi_yaw, nturbines, MPI_REAL, &
2070	MPI_SUM, comm2d, ierr )
2071	#else
2072	u_inflow = u_inflow_l
2073	wdir = wdir_l
2074	phi_yaw = phi_yaw_l
2075	#endif
2076	DO inot = 1, nturbines
2077	!
2078	!-- Update rotor orientation
2079	CALL wtm_rotate_rotor( inot )
2080
2081	ENDDO ! End of loop over turbines
2082
2083	END IF
2084
2085	IF ( speed_control ) THEN
2086	!
2087	!-- Transfer of information to the other cpus
2088	! CALL MPI_ALLREDUCE( omega_gen, omega_gen_old, nturbines, &
2089	! MPI_REAL,MPI_SUM, comm2d, ierr )
2090	#if defined( __parallel )
2091	CALL MPI_ALLREDUCE( torque_gen, torque_gen_old, nturbines, &
2092	MPI_REAL, MPI_SUM, comm2d, ierr )
2093	CALL MPI_ALLREDUCE( omega_rot_l, omega_rot, nturbines, &
2094	MPI_REAL, MPI_SUM, comm2d, ierr )
2095	CALL MPI_ALLREDUCE( omega_gen_f, omega_gen_f_old, nturbines, &
2096	MPI_REAL, MPI_SUM, comm2d, ierr )
2097	#else
2098	torque_gen_old = torque_gen
2099	omega_rot = omega_rot_l
2100	omega_gen_f_old = omega_gen_f
2101	#endif
2102
2103	ENDIF
2104
2105	DO inot = 1, nturbines
2106
2107	IF ( myid == 0 ) THEN
2108	IF ( openfile_turb_mod(400+inot)%opened ) THEN
2109	WRITE ( 400+inot, 106 ) simulated_time, omega_rot(inot), &
2110	omega_gen(inot), torque_gen_old(inot), &
2111	torque_total(inot), pitch_add(inot), &
2112	torque_gen_old(inot)omega_gen(inot)gen_eff, &
2113	torque_total(inot)omega_rot(inot)air_dens, &
2114	thrust_rotor(inot), &
2115	wdir(inot)*180.0_wp/pi, &
2116	(phi_yaw(inot))*180.0_wp/pi
2117
2118	ELSE
2119
2120	WRITE ( turbine_id,'(I2.2)') inot
2121	OPEN ( 400+inot, FILE=( 'TURBINE_PARAMETERS'//turbine_id ), &
2122	FORM='FORMATTED' )
2123	WRITE ( 400+inot, 105 ) inot
2124	WRITE ( 400+inot, 106 ) simulated_time, omega_rot(inot), &
2125	omega_gen(inot), torque_gen_old(inot), &
2126	torque_total(inot), pitch_add(inot), &
2127	torque_gen_old(inot)omega_gen(inot)gen_eff, &
2128	torque_total(inot)omega_rot(inot)air_dens, &
2129	thrust_rotor(inot), &
2130	wdir(inot)*180.0_wp/pi, &
2131	(phi_yaw(inot))*180.0_wp/pi
2132	ENDIF
2133	ENDIF
2134
2135	!-- Set open flag
2136	openfile_turb_mod(400+inot)%opened = .TRUE.
2137	ENDDO !-- end of loop over turbines
2138
2139	ENDIF
2140
2141	CALL cpu_log( log_point_s(61), 'wtm_forces', 'stop' )
2142
2143	!
2144	!-- Formats
2145	105 FORMAT ('Turbine control data for turbine ',I2,1X,':'/ &
2146	&'----------------------------------------'/ &
2147	&' Time RSpeed GSpeed ', &
2148	'GenTorque AeroTorque Pitch Power(Gen) Power(Rot) ', &
2149	'RotThrust WDirection YawOrient')
2150
2151	106 FORMAT (F9.3,2X,F7.3,2X,F7.2,2X,F9.1,3X,F9.1,1X,F6.2,2X,F10.1,2X, &
2152	F10.1,1X,F9.1,2X,F7.2,1X,F7.2)
2153
2154
2155	END SUBROUTINE wtm_forces
2156
2157
2158	!------------------------------------------------------------------------------!
2159	! Description:
2160	! ------------
2161	!> Yaw controller for the wind turbine model
2162	!------------------------------------------------------------------------------!
2163	SUBROUTINE wtm_yawcontrol( inot )
2164
2165	USE constants
2166	USE kinds
2167
2168	IMPLICIT NONE
2169
2170	INTEGER(iwp) :: inot
2171	INTEGER(iwp) :: i_wd_30
2172	REAL(wp) :: missal
2173
2174	i_wd_30 = 0_iwp
2175
2176	!
2177	!-- The yaw controller computes a 30s running mean of the wind direction.
2178	!-- If the difference between turbine alignment and wind direction exceeds
2179	!-- 5Â°, the turbine is yawed. The mechanism stops as soon as the 2s-running
2180	!-- mean of the missalignment is smaller than 0.5Â°.
2181	!-- Attention: If the timestep during the simulation changes significantly
2182	!-- the lengths of the running means change and it does not correspond to
2183	!-- 30s/2s anymore.
2184	!-- ! Needs to be modified for these situations !
2185	!-- For wind from the east, the averaging of the wind direction could cause
2186	!-- problems and the yaw controller is probably flawed. -> Routine for
2187	!-- averaging needs to be improved!
2188	!
2189	!-- Check if turbine is not yawing
2190	IF ( .NOT. doyaw(inot) ) THEN
2191	!
2192	!-- Write current wind direction into array
2193	wd30_l = wd30(inot,:)
2194	wd30_l = CSHIFT( wd30_l, SHIFT=-1 )
2195	wd30_l(1) = wdir(inot)
2196	!
2197	!-- Check if array is full ( no more dummies )
2198	IF ( .NOT. ANY( wd30_l == 999.) ) THEN
2199
2200	missal = SUM( wd30_l ) / SIZE( wd30_l ) - phi_yaw(inot)
2201	!
2202	!-- Check if turbine is missaligned by more than max_miss
2203	IF ( ABS( missal ) > max_miss ) THEN
2204	!
2205	!-- Check in which direction to yaw
2206	yawdir(inot) = SIGN( 1.0_wp, missal )
2207	!
2208	!-- Start yawing of turbine
2209	phi_yaw(inot) = phi_yaw(inot) + yawdir(inot) * yaw_speed * dt_3d
2210	doyaw(inot) = .TRUE.
2211	wd30_l = 999. ! fill with dummies again
2212	ENDIF
2213	ENDIF
2214
2215	wd30(inot,:) = wd30_l
2216
2217	!
2218	!-- If turbine is already yawing:
2219	!-- Initialize 2 s running mean and yaw until the missalignment is smaller
2220	!-- than min_miss
2221
2222	ELSE
2223	!
2224	!-- Initialize 2 s running mean
2225	wd2_l = wd2(inot,:)
2226	wd2_l = CSHIFT( wd2_l, SHIFT = -1 )
2227	wd2_l(1) = wdir(inot)
2228	!
2229	!-- Check if array is full ( no more dummies )
2230	IF ( .NOT. ANY( wd2_l == 999.0_wp ) ) THEN
2231	!
2232	!-- Calculate missalignment of turbine
2233	missal = SUM( wd2_l - phi_yaw(inot) ) / SIZE( wd2_l )
2234	!
2235	!-- Check if missalignment is still larger than 0.5 degree and if the
2236	!-- yaw direction is still right
2237	IF ( ( ABS( missal ) > min_miss ) .AND. &
2238	( yawdir(inot) == SIGN( 1.0_wp, missal ) ) ) THEN
2239	!
2240	!-- Continue yawing
2241	phi_yaw(inot) = phi_yaw(inot) + yawdir(inot) * yaw_speed * dt_3d
2242	ELSE
2243	!
2244	!-- Stop yawing
2245	doyaw(inot) = .FALSE.
2246	wd2_l = 999.0_wp ! fill with dummies again
2247	ENDIF
2248	ELSE
2249	!
2250	!-- Continue yawing
2251	phi_yaw(inot) = phi_yaw(inot) + yawdir(inot) * yaw_speed * dt_3d
2252	ENDIF
2253
2254	wd2(inot,:) = wd2_l
2255
2256	ENDIF
2257
2258	END SUBROUTINE wtm_yawcontrol
2259
2260
2261	!------------------------------------------------------------------------------!
2262	! Description:
2263	! ------------
2264	!> Initialization of the speed control
2265	!------------------------------------------------------------------------------!
2266	SUBROUTINE wtm_init_speed_control
2267
2268
2269	IMPLICIT NONE
2270
2271	!
2272	!-- If speed control is set, remaining variables and control_parameters for
2273	!-- the control algorithm are calculated
2274	!
2275	!-- Calculate slope constant for region 15
2276	slope15 = ( slope2 * min_reg2 * min_reg2 ) / ( min_reg2 - min_reg15 )
2277	!
2278	!-- Calculate upper limit of slipage region
2279	vs_sysp = rated_genspeed / 1.1_wp
2280	!
2281	!-- Calculate slope of slipage region
2282	slope25 = ( rated_power / rated_genspeed ) / &
2283	( rated_genspeed - vs_sysp )
2284	!
2285	!-- Calculate lower limit of slipage region
2286	min_reg25 = ( slope25 - SQRT( slope25 * ( slope25 - 4.0_wp * &
2287	slope2 * vs_sysp ) ) ) / &
2288	( 2.0_wp * slope2 )
2289	!
2290	!-- Frequency for the simple low pass filter
2291	Fcorner = 0.25_wp
2292	!
2293	!-- At the first timestep the torque is set to its maximum to prevent
2294	!-- an overspeeding of the rotor
2295	torque_gen_old(:) = max_torque_gen
2296
2297	END SUBROUTINE wtm_init_speed_control
2298
2299
2300	!------------------------------------------------------------------------------!
2301	! Description:
2302	! ------------
2303	!> Simple controller for the regulation of the rotor speed
2304	!------------------------------------------------------------------------------!
2305	SUBROUTINE wtm_speed_control( inot )
2306
2307
2308	IMPLICIT NONE
2309
2310	INTEGER(iwp) :: inot
2311
2312
2313
2314	!
2315	!-- The controller is based on the fortran script from Jonkman
2316	!-- et al. 2009 "Definition of a 5 MW Reference Wind Turbine for
2317	!-- offshore system developement"
2318
2319	!
2320	!-- The generator speed is filtered by a low pass filter
2321	!-- for the control of the generator torque
2322	lp_coeff = EXP( -2.0_wp * 3.14_wp * dt_3d * Fcorner )
2323	omega_gen_f(inot) = ( 1.0_wp - lp_coeff ) * omega_gen(inot) + lp_coeff *&
2324	omega_gen_f_old(inot)
2325
2326	IF ( omega_gen_f(inot) <= min_reg15 ) THEN
2327	!
2328	!-- Region 1: Generator torque is set to zero to accelerate the rotor:
2329	torque_gen(inot) = 0
2330
2331	ELSEIF ( omega_gen_f(inot) <= min_reg2 ) THEN
2332	!
2333	!-- Region 1.5: Generator torque is increasing linearly with rotor speed:
2334	torque_gen(inot) = slope15 * ( omega_gen_f(inot) - min_reg15 )
2335
2336	ELSEIF ( omega_gen_f(inot) <= min_reg25 ) THEN
2337	!
2338	!-- Region 2: Generator torque is increased by the square of the generator
2339	!-- speed to keep the TSR optimal:
2340	torque_gen(inot) = slope2 * omega_gen_f(inot) * omega_gen_f(inot)
2341
2342	ELSEIF ( omega_gen_f(inot) < rated_genspeed ) THEN
2343	!
2344	!-- Region 2.5: Slipage region between 2 and 3:
2345	torque_gen(inot) = slope25 * ( omega_gen_f(inot) - vs_sysp )
2346
2347	ELSE
2348	!
2349	!-- Region 3: Generator torque is antiproportional to the rotor speed to
2350	!-- keep the power constant:
2351	torque_gen(inot) = rated_power / omega_gen_f(inot)
2352
2353	ENDIF
2354	!
2355	!-- Calculate torque rate and confine with a max
2356	trq_rate = ( torque_gen(inot) - torque_gen_old(inot) ) / dt_3d
2357	trq_rate = MIN( MAX( trq_rate, -1.0_wp * max_trq_rate ), max_trq_rate )
2358	!
2359	!-- Calculate new gen torque and confine with max torque
2360	torque_gen(inot) = torque_gen_old(inot) + trq_rate * dt_3d
2361	torque_gen(inot) = MIN( torque_gen(inot), max_torque_gen )
2362	!
2363	!-- Overwrite values for next timestep
2364	omega_rot_l(inot) = omega_gen(inot) / gear_ratio
2365
2366
2367	END SUBROUTINE wtm_speed_control
2368
2369
2370	!------------------------------------------------------------------------------!
2371	! Description:
2372	! ------------
2373	!> Application of the additional forces generated by the wind turbine on the
2374	!> flow components (tendency terms)
2375	!> Call for all grid points
2376	!------------------------------------------------------------------------------!
2377	SUBROUTINE wtm_tendencies( component )
2378
2379
2380	IMPLICIT NONE
2381
2382	INTEGER(iwp) :: component !< prognostic variable (u,v,w)
2383	INTEGER(iwp) :: i !< running index
2384	INTEGER(iwp) :: j !< running index
2385	INTEGER(iwp) :: k !< running index
2386
2387
2388	SELECT CASE ( component )
2389
2390	CASE ( 1 )
2391	!
2392	!-- Apply the x-component of the force to the u-component of the flow:
2393	IF ( simulated_time >= time_turbine_on ) THEN
2394	DO i = nxlg, nxrg
2395	DO j = nysg, nyng
2396	DO k = nzb_u_inner(j,i)+1, k_hub(1) + k_smear(1)
2397	!
2398	!-- Calculate the thrust generated by the nacelle and the tower
2399	tend_nac_x = 0.5_wp * nac_cd_surf(k,j,i) * &
2400	SIGN( u(k,j,i)**2 , u(k,j,i) )
2401	tend_tow_x = 0.5_wp * tow_cd_surf(k,j,i) * &
2402	SIGN( u(k,j,i)**2 , u(k,j,i) )
2403
2404	tend(k,j,i) = tend(k,j,i) - rot_tend_x(k,j,i) &
2405	- tend_nac_x - tend_tow_x
2406	ENDDO
2407	ENDDO
2408	ENDDO
2409	ENDIF
2410
2411	CASE ( 2 )
2412	!
2413	!-- Apply the y-component of the force to the v-component of the flow:
2414	IF ( simulated_time >= time_turbine_on ) THEN
2415	DO i = nxlg, nxrg
2416	DO j = nysg, nyng
2417	DO k = nzb_v_inner(j,i)+1, k_hub(1) + k_smear(1)
2418	tend_nac_y = 0.5_wp * nac_cd_surf(k,j,i) * &
2419	SIGN( v(k,j,i)**2 , v(k,j,i) )
2420	tend_tow_y = 0.5_wp * tow_cd_surf(k,j,i) * &
2421	SIGN( v(k,j,i)**2 , v(k,j,i) )
2422	tend(k,j,i) = tend(k,j,i) - rot_tend_y(k,j,i) &
2423	- tend_nac_y - tend_tow_y
2424	ENDDO
2425	ENDDO
2426	ENDDO
2427	ENDIF
2428
2429	CASE ( 3 )
2430	!
2431	!-- Apply the z-component of the force to the w-component of the flow:
2432	IF ( simulated_time >= time_turbine_on ) THEN
2433	DO i = nxlg, nxrg
2434	DO j = nysg, nyng
2435	DO k = nzb_w_inner(j,i)+1, k_hub(1) + k_smear(1)
2436	tend(k,j,i) = tend(k,j,i) - rot_tend_z(k,j,i)
2437	ENDDO
2438	ENDDO
2439	ENDDO
2440	ENDIF
2441
2442
2443	CASE DEFAULT
2444
2445	WRITE( message_string, * ) 'unknown prognostic variable: ', component
2446	CALL message( 'wtm_tendencies', 'PA04??', 1, 2, 0, 6, 0 )
2447
2448	END SELECT
2449
2450
2451	END SUBROUTINE wtm_tendencies
2452
2453
2454	!------------------------------------------------------------------------------!
2455	! Description:
2456	! ------------
2457	!> Application of the additional forces generated by the wind turbine on the
2458	!> flow components (tendency terms)
2459	!> Call for grid point i,j
2460	!------------------------------------------------------------------------------!
2461	SUBROUTINE wtm_tendencies_ij( i, j, component )
2462
2463
2464	IMPLICIT NONE
2465
2466	INTEGER(iwp) :: component !< prognostic variable (u,v,w)
2467	INTEGER(iwp) :: i !< running index
2468	INTEGER(iwp) :: j !< running index
2469	INTEGER(iwp) :: k !< running index
2470
2471	SELECT CASE ( component )
2472
2473	CASE ( 1 )
2474	!
2475	!-- Apply the x-component of the force to the u-component of the flow:
2476	IF ( simulated_time >= time_turbine_on ) THEN
2477
2478	DO k = nzb_u_inner(j,i)+1, k_hub(1) + k_smear(1)
2479	!
2480	!-- Calculate the thrust generated by the nacelle and the tower
2481	tend_nac_x = 0.5_wp * nac_cd_surf(k,j,i) * &
2482	SIGN( u(k,j,i)**2 , u(k,j,i) )
2483	tend_tow_x = 0.5_wp * tow_cd_surf(k,j,i) * &
2484	SIGN( u(k,j,i)**2 , u(k,j,i) )
2485	tend(k,j,i) = tend(k,j,i) - rot_tend_x(k,j,i) &
2486	- tend_nac_x - tend_tow_x
2487	ENDDO
2488	ENDIF
2489
2490	CASE ( 2 )
2491	!
2492	!-- Apply the y-component of the force to the v-component of the flow:
2493	IF ( simulated_time >= time_turbine_on ) THEN
2494	DO k = nzb_v_inner(j,i)+1, k_hub(1) + k_smear(1)
2495	tend_nac_y = 0.5_wp * nac_cd_surf(k,j,i) * &
2496	SIGN( v(k,j,i)**2 , v(k,j,i) )
2497	tend_tow_y = 0.5_wp * tow_cd_surf(k,j,i) * &
2498	SIGN( v(k,j,i)**2 , v(k,j,i) )
2499	tend(k,j,i) = tend(k,j,i) - rot_tend_y(k,j,i) &
2500	- tend_nac_y - tend_tow_y
2501	ENDDO
2502	ENDIF
2503
2504	CASE ( 3 )
2505	!
2506	!-- Apply the z-component of the force to the w-component of the flow:
2507	IF ( simulated_time >= time_turbine_on ) THEN
2508	DO k = nzb_w_inner(j,i)+1, k_hub(1) + k_smear(1)
2509	tend(k,j,i) = tend(k,j,i) - rot_tend_z(k,j,i)
2510	ENDDO
2511	ENDIF
2512
2513
2514	CASE DEFAULT
2515
2516	WRITE( message_string, * ) 'unknown prognostic variable: ', component
2517	CALL message( 'wtm_tendencies', 'PA04??', 1, 2, 0, 6, 0 )
2518
2519	END SELECT
2520
2521
2522	END SUBROUTINE wtm_tendencies_ij
2523
2524	END MODULE wind_turbine_model_mod

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