Fitch wind farm scheme bug fix: axial induction factor

LICENSE.txt

@@ -1,3 +1,3 @@
 WRF was developed at the National Center for Atmospheric Research (NCAR) which is operated by the University Corporation for Atmospheric Research (UCAR). NCAR and UCAR make no proprietary claims, either statutory or otherwise, to this version and release of WRF and consider WRF to be in the public domain for use by any person or entity for any purpose without any fee or charge. UCAR requests that any WRF user include this notice on any partial or full copies of WRF. WRF is provided on an "AS IS" basis and any warranties, either express or implied, including but not limited to implied warranties of non-infringement, originality, merchantability and fitness for a particular purpose, are disclaimed. In no event shall UCAR be liable for any damages, whatsoever, whether direct, indirect, consequential or special, that arise out of or in connection with the access, use or performance of WRF, including infringement actions.
 
-WRF® is a registered trademark of the University Corporation for Atmospheric Research (UCAR).
+WRF® is a registered trademark of the University Corporation for Atmospheric Research (UCAR).

Registry/Registry.EM_COMMON

@@ -411,7 +411,9 @@ state   real    bldtacttime    -        -         -         -     r         "bld
 state   real    cudtacttime    -        -         -         -     r         "cudtacttime"              "CUDTACTTIME"         "CPS   ACTIVATION TIME in s"
 state   real    ltngacttime    -        -         -         -     r         "ltngacttime"              "LTNGACTTIME"         "LTNG  ACTIVATION TIME in s"
 state   real    power          ij       misc      1         -     irh       "Power"                   "Power production"         "W"
-
+# THE FOLLOWING LINES OF CODE ARE LICENSED UNDER doc/licenses/fraunhofer_license.txt
+state   real    thrust         ij       misc      1         -     irh       "thrust"                   "Thrust force"         "N"
+# END LICENSE
 
 # State for derived time quantities.  
 state   integer itimestep      -        -          -         -     rh         "itimestep"             ""         ""      
@@ -3003,6 +3005,9 @@ state integer nodyn_dummy - dyn_nodyn -  -  -  "" "" ""
 rconfig   integer     windfarm_opt        namelist,physics      max_domains    0       rh       "windfarm_opt"                ""      ""
 rconfig   integer     windfarm_ij         namelist,physics      1              0       rh       "windfarm_ij"                ""      ""
 rconfig   real        windfarm_tke_factor namelist,physics      1              0.25    rh       "windfarm_tke_factor"        ""      ""
+# THE FOLLOWING LINES OF CODE ARE LICENSED UNDER doc/licenses/fraunhofer_license.txt
+rconfig   integer     windfarm_induction  namelist,physics      1              1       rh       "Fitch axial induction correction"        ""      ""    
+# END LICENSE
 #
 # Ideal case selection
 rconfig   integer     ideal_case          namelist,ideal        1              0       rh       "ideal_case"                 ""      ""
@@ -3389,7 +3394,7 @@ package   wrfhydro       wrf_hydro==1                -            state:SOLDRAIN
 
 #WRF Windfarm
 package   no_windfarm    windfarm_opt==0             -            -
-package   fitchscheme    windfarm_opt==1             -            state:power
+package   fitchscheme    windfarm_opt==1             -            state:power,thrust
 # Yulong add for WLM
 package   mavscheme      windfarm_opt==2             -            state:power
 

doc/licenses/fraunhofer_license.txt

@@ -0,0 +1,21 @@
+MIT License
+
+Copyright (c) 2022 FraunhoferIWES
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.

dyn_em/module_first_rk_step_part1.F

@@ -1114,6 +1114,9 @@ SUBROUTINE first_rk_step_part1 (   grid , config_flags              &
      &         AKHS=grid%akhs          ,AKMS=grid%akms                              &
      &        ,BL_PBL_PHYSICS=config_flags%bl_pbl_physics                           &
      &        ,WINDFARM_OPT=config_flags%windfarm_opt,power=grid%power              &
+     ! THE FOLLOWING LINES OF CODE ARE LICENSED UNDER doc/licenses/fraunhofer_license.txt
+     &        ,thrust=grid%thrust                                                   & 
+     ! END LICENSE
      &        ,windfarm_wake_model=config_flags%windfarm_wake_model          & ! Yulong add for WLM
      &        ,windfarm_overlap_method=config_flags%windfarm_overlap_method  & ! Yulong add for WLM
      &        ,BLDT=grid%bldt, CURR_SECS=curr_secs, ADAPT_STEP_FLAG=adapt_step_flag &

phys/module_pbl_driver.F

@@ -28,6 +28,9 @@ SUBROUTINE pbl_driver(                                          &
                  ,kpbl,mixht,ct,lh,snow,xice                       &
                  ,znu, znw, mut, p_top                             &
                  ,ctopo,ctopo2,windfarm_opt,power                  &
+                 ! THE FOLLOWING LINES OF CODE ARE LICENSED UNDER doc/licenses/fraunhofer_license.txt
+                 ,thrust                                           &
+                 ! END LICENSE
                  ,windfarm_wake_model, windfarm_overlap_method     &
                  ,ysu_topdown_pblmix                               &
                  ,shinhong_tke_diag                                &
@@ -542,6 +545,9 @@ SUBROUTINE pbl_driver(                                          &
                                                             VOCE, &
                                                               T2, &
                                                            POWER, &
+                                                           ! THE FOLLOWING LINES OF CODE ARE LICENSED UNDER doc/licenses/fraunhofer_license.txt
+                                                           THRUST, &
+                                                           ! END LICENSE
                                                             WSPD
    REAL,       DIMENSION( ims:ime, jms:jme )                    , &
                INTENT(INOUT)    ::                     HPBL_HOLD
@@ -2057,6 +2063,9 @@ SUBROUTINE pbl_driver(                                          &
                      &,QKE=qke                                           &
                      &,DU=rublten,DV=rvblten                             &
                      &,WINDFARM_OPT=windfarm_opt,POWER=power             &
+                     ! THE FOLLOWING LINES OF CODE ARE LICENSED UNDER doc/licenses/fraunhofer_license.txt
+                     &,THRUST=thrust                                     &
+                     ! END LICENSE
                      &,IDS=ids,IDE=ide,JDS=jds,JDE=jde,KDS=kds,KDE=kde   &
                      &,IMS=ims,IME=ime,JMS=jms,JME=jme,KMS=kms,KME=kme   &
                      &,ITS=its,ITE=ite,JTS=jts,JTE=jte,KTS=kts,KTE=kte   &

phys/module_wind_fitch.F

@@ -61,6 +61,9 @@ MODULE module_wind_fitch
 !
   REAL :: turbws(maxvals,maxvals2),turbtc(maxvals,maxvals2),turbpw(maxvals,maxvals2)
   REAL :: correction_factor
+  ! THE FOLLOWING LINES OF CODE ARE LICENSED UNDER doc/licenses/fraunhofer_license.txt
+  INTEGER :: induction_correction
+  ! END LICENSE
 !
 CONTAINS
 
@@ -70,6 +73,9 @@ SUBROUTINE  dragforce(                      &
        &,dx,dz,dt,qke                            &
        &,du,dv                                   &
        &,windfarm_opt,power                      &
+       ! THE FOLLOWING LINES OF CODE ARE LICENSED UNDER doc/licenses/fraunhofer_license.txt
+       &,thrust                                  &
+       ! END LICENSE
        &,ids,ide,jds,jde,kds,kde                 &
        &,ims,ime,jms,jme,kms,kme                 &
        &,its,ite,jts,jte,kts,kte                 &
@@ -85,6 +91,9 @@ SUBROUTINE  dragforce(                      &
   REAL, DIMENSION(ims:ime,kms:kme,jms:jme), INTENT(IN) :: dz,u,v,z_at_w
   REAL, DIMENSION(ims:ime,kms:kme,jms:jme), INTENT(INOUT) :: du,dv,qke
   REAL, DIMENSION(ims:ime,jms:jme), INTENT(INOUT) :: power
+  ! THE FOLLOWING LINES OF CODE ARE LICENSED UNDER doc/licenses/fraunhofer_license.txt
+  REAL, DIMENSION(ims:ime,jms:jme), INTENT(INOUT) :: thrust
+  ! END LICENSE
 !
 ! Local
 !
@@ -101,13 +110,23 @@ SUBROUTINE  dragforce(                      &
   REAL :: speedhub,speed1,speed2
   real :: power1,power2,area,ec
   INTEGER :: kbot,ktop,kt
-
+  ! THE FOLLOWING LINES OF CODE ARE LICENSED UNDER doc/licenses/fraunhofer_license.txt
+  REAL :: a_ind ! axial induction factor
+  REAL :: thrust1
+  INTEGER :: ii ! running index
+  INTEGER, DIMENSION(:), ALLOCATABLE :: idx ! temporary array of indices
+  INTEGER :: nturb ! number of turbines in grid cell
+  ! END LICENSE
+
   itf=MIN0(ite,ide-1)
   jtf=MIN0(jte,jde-1)
   ktf=MIN0(kte,kde-1)
 
     wfdensity = 1.0/(dx*dx)   !  per turbine, so numerator is 1
     power=0.
+    ! THE FOLLOWING LINES OF CODE ARE LICENSED UNDER doc/licenses/fraunhofer_license.txt
+    thrust=0.
+    ! END LICENSE
 
     DO kt = 1,nt  
       IF ( windfarm_opt .eq. 1 ) THEN
@@ -118,6 +137,15 @@ SUBROUTINE  dragforce(                      &
         k_turbine_top=-1     !top level
         i = ival(kt,id)
         j = jval(kt,id)
+
+        ! THE FOLLOWING LINES OF CODE ARE LICENSED UNDER doc/licenses/fraunhofer_license.txt
+        if (induction_correction == 1) then
+          ! BAMS: Number of turbines in current grid cell
+          idx = PACK([(ii, ii=1,nt)], ival(:,id) == i) ! indices of values equal to i in ival
+          idx = PACK([(ii, ii=1,SIZE(jval(idx,id)))], jval(idx,id) == j) ! indices of values equal j in jval(idx)
+          nturb = SIZE(idx) ! number of turbines in grid cell (i,j)
+        endif
+        ! END LICENSE
 !
          if (i.ne.-9999.and.j.ne.-9999) then
         IF (( its .LE. i .AND. i .LE. itf ) .AND. &
@@ -168,28 +196,85 @@ SUBROUTINE  dragforce(                      &
               zheightl = z2 + 0.5*dz(i,k,j)
             ENDIF
           ENDDO
-!
+      area = piconst/4.*diameter(kt)**2.       ! area swept by turbine blades
+
+      ! THE FOLLOWING LINES OF CODE ARE LICENSED UNDER doc/licenses/fraunhofer_license.txt
+        IF (induction_correction == 0) THEN ! original Fitch scheme
+      ! END LICENSE
           speed1=0.
           speed2=0.
+          a_ind=0.01
           if (ktop.eq.1) then
            speedhub=sqrt(u(i,1,j)**2.+v(i,1,j)**2.)*hubheight(kt)/z1
+           speedhub=speedhub/((1-a_ind)**nturb) ! BAMS
           else
            speed1=sqrt(u(i,kbot,j)**2.+v(i,kbot,j)**2.)
            speed2=sqrt(u(i,ktop,j)**2.+v(i,ktop,j)**2.)
            speedhub=speed1+((speed2-speed1)/(z2-z1))*(hubheight(kt)-z1)
+           speedhub=speedhub/((1-a_ind)**nturb) ! BAMS
           endif
 !
 ! ... calculate TKE, power and thrust coeffs
 !
               CALL dragcof(tkecof,powcof,thrcof,               &
                            speedhub,cutin(kt),cutout(kt),   &
-                           npower(kt),diameter(kt),stc(kt),stc2(kt),nkind(kt))
+                           npower(kt),diameter(kt),stc(kt),stc2(kt),nkind(kt))      
+
+
+        ! THE FOLLOWING LINES OF CODE ARE LICENSED UNDER doc/licenses/fraunhofer_license.txt
+        ELSEIF (induction_correction == 1) THEN ! Fitch scheme with induction correction
+          ! ... BAMS: first iteration with induction first estimate
+          speed1=0.
+          speed2=0.
+          a_ind=0.01
+          if (ktop.eq.1) then
+           speedhub=sqrt(u(i,1,j)**2.+v(i,1,j)**2.)*hubheight(kt)/z1
+           speedhub=speedhub/((1-a_ind)**nturb)
+          else
+           speed1=sqrt(u(i,kbot,j)**2.+v(i,kbot,j)**2.)
+           speed2=sqrt(u(i,ktop,j)**2.+v(i,ktop,j)**2.)
+           speedhub=speed1+((speed2-speed1)/(z2-z1))*(hubheight(kt)-z1)
+           speedhub=speedhub/((1-a_ind)**nturb)
+          endif
+!
+! ... calculate TKE, power and thrust coeffs
+!
+          CALL dragcof(tkecof,powcof,thrcof,               &
+                        speedhub,cutin(kt),cutout(kt),   &
+                        npower(kt),diameter(kt),stc(kt),stc2(kt),nkind(kt))
+
+          ! ... BAMS: second iteration
+          a_ind = 0.5 * (1 - sqrt(1 - thrcof))
+          a_ind = a_ind * area / ( diameter(kt) * dx * &
+                  MIN(ABS(1/COS(ATAN( ((v(i,ktop,j) + v(i,kbot,j))/2) / ((u(i,ktop,j) + u(i,kbot,j))/2) ))), &
+                      ABS(1/SIN(ATAN( ((v(i,ktop,j) + v(i,kbot,j))/2) / ((u(i,ktop,j) + u(i,kbot,j))/2) )))) )     ! Corrected induction factor
+
+          speed1=0.
+          speed2=0.
+          if (ktop.eq.1) then
+          speedhub=sqrt(u(i,1,j)**2.+v(i,1,j)**2.)*hubheight(kt)/z1
+          speedhub=speedhub/((1-a_ind)**nturb)
+          else
+          speed1=sqrt(u(i,kbot,j)**2.+v(i,kbot,j)**2.)
+          speed2=sqrt(u(i,ktop,j)**2.+v(i,ktop,j)**2.)
+          speedhub=speed1+((speed2-speed1)/(z2-z1))*(hubheight(kt)-z1)
+          speedhub=speedhub/((1-a_ind)**nturb)
+          endif
+
+         CALL dragcof(tkecof,powcof,thrcof,               &
+                       speedhub,cutin(kt),cutout(kt),   &
+                       npower(kt),diameter(kt),stc(kt),stc2(kt),nkind(kt))
+        ENDIF
+       ! END LICENSE
 !
 ! ... PAJ: Computation of power generated by the wind turbine ...
 !
-          area=piconst/4.*diameter(kt)**2.          ! area swept by turbine blades
           power1=0.5*1.23*speedhub**3.*area*powcof
           power(i,j)=power1+power(i,j)
+          ! THE FOLLOWING LINES OF CODE ARE LICENSED UNDER doc/licenses/fraunhofer_license.txt
+          thrust1=0.5*1.23*speedhub**2.*area*thrcof
+          thrust(i,j)=thrust1+thrust(i,j)
+          ! END LICENSE
           power2=0.
 !
             DO k=k_turbine_bot,k_turbine_top ! loop over turbine blade levels
@@ -200,6 +285,11 @@ SUBROUTINE  dragforce(                      &
               CALL turbine_area(z1,z2,diameter(kt),wfdensity,tarea)
 !
               speed=sqrt(u(i,k,j)**2.+v(i,k,j)**2.)
+              ! THE FOLLOWING LINES OF CODE ARE LICENSED UNDER doc/licenses/fraunhofer_license.txt
+              IF (induction_correction == 1) THEN ! original Fitch scheme
+                speed= speed / ((1-a_ind)**nturb)
+              ENDIF
+              ! END LICENSE
               power2=power2+0.5*powcof*1.23*(speed**3.)*tarea/wfdensity
             ENDDO
 !
@@ -214,6 +304,11 @@ SUBROUTINE  dragforce(                      &
               CALL turbine_area(z1,z2,diameter(kt),wfdensity,tarea)
 !
               speed=sqrt(u(i,k,j)**2.+v(i,k,j)**2.)
+              ! THE FOLLOWING LINES OF CODE ARE LICENSED UNDER doc/licenses/fraunhofer_license.txt
+              IF (induction_correction == 1) THEN ! original Fitch scheme
+                speed= speed / ((1-a_ind)**nturb)
+              ENDIF
+              ! END LICENSE
 !`
 ! ... PAJ: normalization introduced to conserve energy ...
 !
@@ -225,10 +320,22 @@ SUBROUTINE  dragforce(                      &
 !
               ! output TKE
               qke(i,k,j) = qke(i,k,j)+speed**3.*tarea*tkecof*dt/dz(i,k,j)*ec
-              ! output u tendency
-              du(i,k,j) = du(i,k,j)-.5*u(i,k,j)*thrcof*speed*tarea/dz(i,k,j)*ec
-              ! output v tendency
-              dv(i,k,j) = dv(i,k,j)-.5*v(i,k,j)*thrcof*speed*tarea/dz(i,k,j)*ec
+              ! THE FOLLOWING LINES OF CODE ARE LICENSED UNDER doc/licenses/fraunhofer_license.txt
+              IF (induction_correction == 0) THEN
+              ! END LICENSE
+                ! output u tendency
+                du(i,k,j) = du(i,k,j)-.5*u(i,k,j)*thrcof*speed*tarea/dz(i,k,j)*ec
+                ! output v tendency
+                dv(i,k,j) = dv(i,k,j)-.5*v(i,k,j)*thrcof*speed*tarea/dz(i,k,j)*ec
+
+              ! THE FOLLOWING LINES OF CODE ARE LICENSED UNDER doc/licenses/fraunhofer_license.txt
+              ELSEIF (induction_correction == 1) THEN
+                ! output u tendency
+                du(i,k,j) = du(i,k,j)-.5*(u(i,k,j)/((1-a_ind)**nturb))*thrcof*speed*tarea/dz(i,k,j)*ec
+                ! output v tendency
+                dv(i,k,j) = dv(i,k,j)-.5*(v(i,k,j)/((1-a_ind)**nturb))*thrcof*speed*tarea/dz(i,k,j)*ec
+              ENDIF
+              ! END LICENSE
             ENDDO
           ENDIF
         ENDIF
@@ -310,6 +417,11 @@ SUBROUTINE dragcof(tkecof,powcof,thrcof,speed,cispeed,cospeed, &
      thrcof = turbtc(nkind,nb)+(turbtc(nkind,nu)-turbtc(nkind,nb))/(turbws(nkind,nu)-turbws(nkind,nb))*(speed-turbws(nkind,nb))
     ENDIF
   ENDIF
+  ! THE FOLLOWING LINES OF CODE ARE LICENSED UNDER doc/licenses/fraunhofer_license.txt
+  IF (induction_correction == 1) THEN
+    thrcof = MAX(MIN(thrcof,0.9999),0.0001) ! BAMS
+  ENDIF
+  ! END LICENSE
 !
 ! ... power coeficient ...
 !
@@ -354,6 +466,9 @@ SUBROUTINE init_module_wind_fitch(id,config_flags,xlong,xlat,windfarm_initialize
 !
 
    correction_factor = config_flags%windfarm_tke_factor
+   ! THE FOLLOWING LINES OF CODE ARE LICENSED UNDER doc/licenses/fraunhofer_license.txt
+   induction_correction = config_flags%windfarm_induction
+   ! END LICENSE
       IF ( wrf_dm_on_monitor() ) THEN
 !
 ! ... PAJ: Opens the file with the location of the wind turbines ...

run/README.namelist

@@ -1133,6 +1133,9 @@ Options for wind turbine drag parameterization:
                                                 ! 1 = The coordinate of the turbines are defined in terms of grid points
                                                 ! 2 = Valid only with windfarm_opt=2. The coordinate of the turbines are defined
                                                       in terms of lat-lon with the filename of 'windturbines-ll.txt'
+ ! THE FOLLOWING LINES OF CODE ARE LICENSED UNDER doc/licenses/fraunhofer_license.txt                                                    
+ windfarm_induction                 = 1         ! Use the axial induction correction as described by Vollmer et al (2024). Valid only with 'windfarm_opt=1'. 0: Off, 1: On (default)
+ ! END LICENSE
  windfarm_wake_model                = 2         ! Subgrid-scale wind turbine wake model, valid only with windfarm_opt=2, default is 2
                                                 ! 1 = The Jensen model
                                                 ! 2 = The XA model