FDS Source: add MAX_PREDICTOR_PRESSURE_ITERATIONS option on PRES

Source/cons.f90

@@ -521,6 +521,7 @@ MODULE GLOBAL_CONSTANTS
 INTEGER, ALLOCATABLE, DIMENSION(:,:) :: VELOCITY_ERROR_MAX_LOC   !< Indices of max velocity error
 INTEGER, ALLOCATABLE, DIMENSION(:,:) :: PRESSURE_ERROR_MAX_LOC   !< Indices of max pressure error
 INTEGER :: PRESSURE_ITERATIONS=0                                 !< Counter for pressure iterations
+INTEGER :: MAX_PREDICTOR_PRESSURE_ITERATIONS=-1                  !< Max pressure iterations per pressure solve in predictor
 INTEGER :: MAX_PRESSURE_ITERATIONS=10                            !< Max pressure iterations per pressure solve
 INTEGER :: TOTAL_PRESSURE_ITERATIONS=0                           !< Counter for total pressure iterations
 CHARACTER(LABEL_LENGTH) :: PRES_METHOD='FFT'                     !< Pressure solver method

Source/fire.f90

@@ -1182,7 +1182,7 @@ END SUBROUTINE CALC_ADIABATIC_FLAME_TEMPERATURE
 ! Calculate Reactants and products
 SUBROUTINE CALC_AFT_REAC_AND_PROD(ZZ,ZZ_REAC,ZZ_PROD)
 USE PHYSICAL_FUNCTIONS, ONLY: CALC_EQUIV_RATIO
-USE CHEMCONS, ONLY: I_FUEL,I_CO2,I_H2O,I_O2,I_N2,USE_MIXED_ZN_AFT_TMP
+USE CHEMCONS, ONLY: I_FUEL,I_CO2,I_H2O,I_O2,USE_MIXED_ZN_AFT_TMP
 
 REAL(EB), INTENT(IN) :: ZZ(N_TRACKED_SPECIES)
 REAL(EB), INTENT(OUT) :: ZZ_REAC(N_TRACKED_SPECIES),ZZ_PROD(N_TRACKED_SPECIES)
@@ -1193,37 +1193,37 @@ SUBROUTINE CALC_AFT_REAC_AND_PROD(ZZ,ZZ_REAC,ZZ_PROD)
 
 CALL CALC_EQUIV_RATIO(ZZ(1:N_TRACKED_SPECIES), EQUIV)
 IF (SIM_MODE /= DNS_MODE .AND. USE_MIXED_ZN_AFT_TMP) THEN
-   EQUIV = MAX(1.0_EB,EQUIV)
+   EQUIV = MAX(1._EB,EQUIV)
 ENDIF
 
 ! Adjust for diluents
-ZZ_FUEL_O2_MASS = 0.0_EB
+ZZ_FUEL_O2_MASS = 0._EB
 ZZ_MASS = SUM(ZZ(1:N_TRACKED_SPECIES))
 ZZ_REAC(1:N_TRACKED_SPECIES) = ZZ(1:N_TRACKED_SPECIES)
 ZZ_PROD(1:N_TRACKED_SPECIES) = ZZ(1:N_TRACKED_SPECIES)
 DO NS=1, N_TRACKED_SPECIES
-   IF (SPECIES_MIXTURE(NS)%OXR > 0.0_EB) THEN ! FUEL
-      ZZ_REAC(NS) = 0.0_EB
-      ZZ_PROD(NS) = 0.0_EB
+   IF (SPECIES_MIXTURE(NS)%OXR > TWO_EPSILON_EB) THEN ! FUEL
+      ZZ_REAC(NS) = 0._EB
+      ZZ_PROD(NS) = 0._EB
       ZZ_FUEL_O2_MASS = ZZ_FUEL_O2_MASS + ZZ(NS)
    ENDIF   
 ENDDO
-ZZ_REAC(I_O2) = 0.0_EB
-ZZ_PROD(I_O2) = 0.0_EB
+ZZ_REAC(I_O2) = 0._EB
+ZZ_PROD(I_O2) = 0._EB
 ZZ_FUEL_O2_MASS = ZZ_FUEL_O2_MASS + ZZ(I_O2)
 
 ! Based on CxHyOz + aO2 = bCO2 + cH2O + dCxHyOz + eO2 
 X=SPECIES_MIXTURE(I_FUEL)%ATOMS(6) !C
 Y=SPECIES_MIXTURE(I_FUEL)%ATOMS(1) !H
 Z=SPECIES_MIXTURE(I_FUEL)%ATOMS(8) !O
-A=0.5_EB*((2.0_EB*X+0.5_EB*Y)/EQUIV -Z) ! a is a function of equivalence ratio
-IF(ABS(EQUIV - 1.0_EB) <1E-3_EB) THEN ! Stoich
+A=0.5_EB*((2._EB*X+0.5_EB*Y)/EQUIV -Z) ! a is a function of equivalence ratio
+IF (ABS(EQUIV - 1.0_EB) < TWO_EPSILON_EB) THEN ! Stoich
    B = X
    C = 0.5_EB*Y
    D = 0._EB ! No fuel
    E = 0._EB ! No O2
 ELSEIF (EQUIV > 1) THEN ! Rich
-   D = (2.0_EB*X+0.5_EB*Y-2.0_EB*A-Z)/(2.0_EB*X+0.5_EB*Y-Z)
+   D = (2._EB*X+0.5_EB*Y-2._EB*A-Z)/(2._EB*X+0.5_EB*Y-Z)
    B = (1._EB-D)*X
    C = 0.5_EB*(1._EB-D)*Y
    E = 0._EB ! No O2

Source/main.f90

@@ -1520,9 +1520,12 @@ SUBROUTINE PRESSURE_ITERATION_SCHEME
 
    IF (MAXVAL(PRESSURE_ERROR_MAX)<PRESSURE_TOLERANCE) ITERATE_BAROCLINIC_TERM = .FALSE.
 
-   IF ((MAXVAL(PRESSURE_ERROR_MAX)<PRESSURE_TOLERANCE .AND. &
-        MAXVAL(VELOCITY_ERROR_MAX)<VELOCITY_TOLERANCE) .OR. PRESSURE_ITERATIONS>=MAX_PRESSURE_ITERATIONS) &
+   IF (PREDICTOR .AND. PRESSURE_ITERATIONS>=MAX_PREDICTOR_PRESSURE_ITERATIONS) EXIT PRESSURE_ITERATION_LOOP
+   IF (CORRECTOR .AND. PRESSURE_ITERATIONS>=MAX_PRESSURE_ITERATIONS)           EXIT PRESSURE_ITERATION_LOOP
+
+   IF (MAXVAL(PRESSURE_ERROR_MAX)<PRESSURE_TOLERANCE .AND. MAXVAL(VELOCITY_ERROR_MAX)<VELOCITY_TOLERANCE) THEN
       EXIT PRESSURE_ITERATION_LOOP
+   ENDIF
 
    ! Exit the iteration loop if satisfactory progress is not achieved
 

Source/read.f90

@@ -9932,7 +9932,7 @@ SUBROUTINE READ_PRES
 INTEGER :: NM
 
 NAMELIST /PRES/ BAROCLINIC,CHECK_POISSON,FISHPAK_BC,ITERATION_SUSPEND_FACTOR, &
-                MAX_PRESSURE_ITERATIONS,PRESSURE_RELAX_TIME,PRESSURE_TOLERANCE, &
+                MAX_PREDICTOR_PRESSURE_ITERATIONS,MAX_PRESSURE_ITERATIONS,PRESSURE_RELAX_TIME,PRESSURE_TOLERANCE, &
                 RELAXATION_FACTOR,SOLVER,SUSPEND_PRESSURE_ITERATIONS,TUNNEL_PRECONDITIONER,VELOCITY_TOLERANCE, &
                 WRITE_PARCSRPCG_MATRIX
 
@@ -10028,6 +10028,8 @@ SUBROUTINE READ_PRES
    IF (PRESSURE_TOLERANCE<TWO_EPSILON_EB) PRESSURE_TOLERANCE = 20.0_EB/MIN(1._EB,CHARACTERISTIC_CELL_SIZE)**2
 ENDIF
 
+! Error checks
+
 IF (NMESHES>1 .AND. ANY(FISHPAK_BC==FISHPAK_BC_PERIODIC)) THEN
    CALL SHUTDOWN('ERROR(372): Cannot use FISHPAK_BC for multiple mesh simulations.') ; RETURN
 ENDIF
@@ -10058,6 +10060,10 @@ SUBROUTINE READ_PRES
    ALLOCATE(H_BAR(0:TUNNEL_NXP+1))    ; H_BAR      = 0._EB
 ENDIF
 
+! Optionally set a different number of max pressure iterations in the predictor stage
+
+IF (MAX_PREDICTOR_PRESSURE_ITERATIONS<0) MAX_PREDICTOR_PRESSURE_ITERATIONS = MAX_PRESSURE_ITERATIONS
+
 END SUBROUTINE READ_PRES