Merge pull request #15140 from cxp484/master

FDS Source: Remove I_N2 variable

Author: cxp484

Source/cons.f90

@@ -920,7 +920,7 @@ MODULE CHEMCONS
 
 ! Adiabatic flame temperature calculation
 CHARACTER(LABEL_LENGTH) :: FUEL_ID_FOR_AFT='null'
-INTEGER :: I_FUEL,I_CO2,I_H2O,I_O2,I_N2 ! Store the index of the species in the ZZ array.
+INTEGER :: I_FUEL,I_CO2,I_H2O,I_O2 ! Store the index of the species in the ZZ array.
 LOGICAL  :: USE_MIXED_ZN_AFT_TMP = .FALSE.
 
 ! Mixing

Source/read.f90

@@ -5100,7 +5100,7 @@ END SUBROUTINE READ_REAC
 
 
 SUBROUTINE PROC_REAC_1
-USE CHEMCONS, ONLY: YP2ZZ,FUEL_ID_FOR_AFT,I_FUEL,I_CO2,I_H2O,I_O2,I_N2
+USE CHEMCONS, ONLY: YP2ZZ,FUEL_ID_FOR_AFT,I_FUEL,I_CO2,I_H2O,I_O2
 USE PROPERTY_DATA, ONLY : PARSE_EQUATION, SHUTDOWN_ATOM
 REAL(EB) :: MASS_PRODUCT,MASS_REACTANT,REACTION_BALANCE(118),NU_Y(N_SPECIES)
 INTEGER :: NS,NS2, NR
@@ -5532,7 +5532,6 @@ SUBROUTINE PROC_REAC_1
 IF(TRIM(ODE_SOLVER)=='CVODE') THEN
    I_FUEL = -1
    I_O2 = -1
-   I_N2 = -1
    I_CO2 = -1
    I_H2O = -1
 
@@ -5541,8 +5540,6 @@ SUBROUTINE PROC_REAC_1
          I_FUEL = NS
       ELSEIF(TRIM(SPECIES_MIXTURE(NS)%ID) == "O2" .OR. TRIM(SPECIES_MIXTURE(NS)%ID) == "OXYGEN") THEN
          I_O2 = NS
-      ELSEIF(TRIM(SPECIES_MIXTURE(NS)%ID) == "N2" .OR. TRIM(SPECIES_MIXTURE(NS)%ID) == "NITROGEN") THEN
-         I_N2 = NS
       ELSEIF(TRIM(SPECIES_MIXTURE(NS)%ID) == "CO2" .OR. TRIM(SPECIES_MIXTURE(NS)%ID) == "CARBON DIOXIDE") THEN
          I_CO2 = NS   
       ELSEIF(TRIM(SPECIES_MIXTURE(NS)%ID) == "H2O" .OR. TRIM(SPECIES_MIXTURE(NS)%ID) == "WATER VAPOR") THEN