FDS Source: Issue #14401. Streamline exchange of vent areas

Author: mcgratta

Source/cons.f90

@@ -759,7 +759,7 @@ MODULE GLOBAL_CONSTANTS
 LOGICAL, ALLOCATABLE, DIMENSION(:) :: EXTERNAL_CTRL
 
 ! VENT array
-REAL(EB), ALLOCATABLE, DIMENSION(:,:) :: VENT_TOTAL_AREA
+REAL(EB), ALLOCATABLE, DIMENSION(:) :: VENT_TOTAL_AREA  !< Array holding grid-snapped areas for all vents
 
 END MODULE GLOBAL_CONSTANTS
 

Source/main.f90

@@ -72,7 +72,7 @@ PROGRAM FDS
 CHARACTER(MPI_MAX_PROCESSOR_NAME) :: PNAME
 LOGICAL, ALLOCATABLE, DIMENSION(:)        :: LOGICAL_BUFFER_EXTERNAL
 REAL(EB), ALLOCATABLE, DIMENSION(:)       :: REAL_BUFFER_DUCT,REAL_BUFFER_EXTERNAL
-REAL(EB), ALLOCATABLE, DIMENSION(:,:)     :: REAL_BUFFER_10,REAL_BUFFER_20,REAL_BUFFER_VENT
+REAL(EB), ALLOCATABLE, DIMENSION(:,:)     :: REAL_BUFFER_10,REAL_BUFFER_20
 
 ! Initialize OpenMP
 
@@ -1053,7 +1053,6 @@ SUBROUTINE MPI_INITIALIZATION_CHORES(TASK_NUMBER)
       ALLOCATE(REAL_BUFFER_DUCT((2+N_TRACKED_SPECIES)*N_DUCTNODES+N_DUCTS))
       ALLOCATE(REAL_BUFFER_10(10,NMESHES))
       ALLOCATE(REAL_BUFFER_20(20,NMESHES))
-      ALLOCATE(REAL_BUFFER_VENT(N_VENT_TOTAL,NMESHES))
 
       IF (READ_EXTERNAL) THEN
          ALLOCATE(REAL_BUFFER_EXTERNAL(N_RAMP))
@@ -1064,13 +1063,11 @@ SUBROUTINE MPI_INITIALIZATION_CHORES(TASK_NUMBER)
       ALLOCATE(COUNTS_10(0:N_MPI_PROCESSES-1))
       ALLOCATE(COUNTS_20(0:N_MPI_PROCESSES-1))
       ALLOCATE(COUNTS_TP(0:N_MPI_PROCESSES-1))
-      ALLOCATE(COUNTS_VENT(0:N_MPI_PROCESSES-1))
 
       ALLOCATE(DISPLS(0:N_MPI_PROCESSES-1))
       ALLOCATE(DISPLS_10(0:N_MPI_PROCESSES-1))
       ALLOCATE(DISPLS_20(0:N_MPI_PROCESSES-1))
       ALLOCATE(DISPLS_TP(0:N_MPI_PROCESSES-1))
-      ALLOCATE(DISPLS_VENT(0:N_MPI_PROCESSES-1))
       ALLOCATE(I_OFFSET(NMESHES))
 
       COUNTS    = 0
@@ -1095,8 +1092,6 @@ SUBROUTINE MPI_INITIALIZATION_CHORES(TASK_NUMBER)
          DISPLS(N)    = COUNTS(N-1)    + DISPLS(N-1)
          DISPLS_TP(N) = COUNTS_TP(N-1) + DISPLS_TP(N-1)
       ENDDO
-      COUNTS_VENT = COUNTS*N_VENT_TOTAL
-      DISPLS_VENT = DISPLS*N_VENT_TOTAL
       COUNTS_10 = COUNTS*10
       DISPLS_10 = DISPLS*10
       COUNTS_20 = COUNTS*20
@@ -4275,22 +4270,17 @@ SUBROUTINE CHECK_FREEZE_VELOCITY_STATUS
 END SUBROUTINE CHECK_FREEZE_VELOCITY_STATUS
 
 
-!> \brief Exchange FDS VENT areas so each process knows the total FDS area
+!> \brief Sum up local grid-snapped or "FDS" VENT areas so that each process knows the total vent area spanning multiple meshes
 
 SUBROUTINE EXCHANGE_VENT_AREA
-INTEGER:: NM,NV
+INTEGER :: NM,NV
 
-IF (N_MPI_PROCESSES>1) THEN
-   REAL_BUFFER_VENT = VENT_TOTAL_AREA
-   CALL MPI_ALLGATHERV(MPI_IN_PLACE,0,MPI_DATATYPE_NULL,REAL_BUFFER_VENT,&
-                        COUNTS_VENT,DISPLS_VENT,MPI_DOUBLE_PRECISION,MPI_COMM_WORLD,IERR)
-   VENT_TOTAL_AREA = REAL_BUFFER_VENT
-ENDIF
+CALL MPI_ALLREDUCE(MPI_IN_PLACE,VENT_TOTAL_AREA,N_VENT_TOTAL,MPI_DOUBLE_PRECISION,MPI_SUM,MPI_COMM_WORLD,IERR)
 
-DO NM=1,NMESHES
-   IF (PROCESS(NM)/=MY_RANK) CYCLE
-   DO NV=1,MESHES(NM)%N_VENT
-      MESHES(NM)%VENTS(NV)%TOTAL_FDS_AREA=SUM(VENT_TOTAL_AREA(MESHES(NM)%VENTS(NV)%TOTAL_INDEX,:))
+DO NM=LOWER_MESH_INDEX,UPPER_MESH_INDEX
+   M => MESHES(NM)
+   DO NV=1,M%N_VENT
+      M%VENTS(NV)%TOTAL_FDS_AREA = VENT_TOTAL_AREA(M%VENTS(NV)%TOTAL_INDEX)
    ENDDO
 ENDDO
 

Source/read.f90

@@ -11777,7 +11777,7 @@ SUBROUTINE READ_VENT
 
    IF (I_MODE==2) THEN
       ALLOCATE(MESHES(NM)%VENTS(N_VENT),STAT=IZERO) ; CALL ChkMemErr('READ','VENTS',IZERO) ; VENTS=>MESHES(NM)%VENTS
-      IF (.NOT. ALLOCATED(VENT_TOTAL_AREA)) ALLOCATE(VENT_TOTAL_AREA(N_VENT_TOTAL,NMESHES),STAT=IZERO) ! Only once per MPI process
+      IF (.NOT. ALLOCATED(VENT_TOTAL_AREA)) ALLOCATE(VENT_TOTAL_AREA(N_VENT_TOTAL),STAT=IZERO) ! Only once per MPI process
       CALL ChkMemErr('READ','VENT_TOTAL_AREA',IZERO); VENT_TOTAL_AREA = 0._EB
       IF (MY_RANK==0 .AND. .NOT.ALLOCATED(ORIGINAL_VENTS)) ALLOCATE(ORIGINAL_VENTS(N_ORIGINAL_VENTS))
    ENDIF
@@ -11787,7 +11787,7 @@ SUBROUTINE READ_VENT
    N_VENT           = 0  ! Number of VENTs stored by each mesh
    N_TOTAL          = 0  ! Counter of all VENTs, both explicit and implicit
    N_EXPLICIT       = 0  ! Counter of explicitly declared VENTs
-   N_VENT_TOTAL     = 0  ! Purely for Smokeview drawing of VENTs
+   N_VENT_TOTAL     = 0  ! Total number of all vents throughout the whole domain
    N_ORIGINAL_VENTS = 0  ! Number of specified vents for use with Smokeview and HVAC drawing
 
    REWIND(LU_INPUT) ; INPUT_FILE_LINE_NUMBER = 0
@@ -12443,7 +12443,7 @@ SUBROUTINE READ_VENT
                ENDDO
             ENDDO
       END SELECT
-      VENT_TOTAL_AREA(VT%TOTAL_INDEX,NM) = VT%FDS_AREA
+      VENT_TOTAL_AREA(VT%TOTAL_INDEX) = VENT_TOTAL_AREA(VT%TOTAL_INDEX) + VT%FDS_AREA
    ENDDO  VENT_LOOP_3
 
 ENDDO MESH_LOOP_2