SUBROUTINE ENTHALP (Temp,I,Enthalpy,*)                                   
C***********************************************************************
C*    SUBROUTINE:            ENTHALP
C*    
C*    LANGUAGE:              FORTRAN 77
C*   
C*    PURPOSE:               Calculate the enthalpy (J/kmol) of each
C*                           species (H2,O2,N2,CO2,H2O) at a given
C*                           temperature
C***********************************************************************
C*    INPUT VARIABLES
C*    Temp         Temperature at which enthalpy must be calculated  (K)
C*    I            Selection of the species to be considered         (-)
C*                 I=1: H2
C*                 I=2: O2
C*                 I=3: N2
C*                 I=4: CO2
C*                 I=5: H2O
C*
C*    OUTPUT VARIABLES
C*    Enthalpy     Enthalpy of the species                      (J/kmol)
C***********************************************************************
C     DEVELOPER:             Philippe Ngendakumana
C                            Marc Grodent
C                            University of LiŠge, Belgium
C
C     DATE:                  November 8, 1993
C
C     REFERENCE:             A. Brohmer and P. Kreuter
C                            FEV Motorentechnik GmbH & Co KG
C                            Aachen, Germany
C***********************************************************************
C     INTERNAL VARIABLES
C     PFCP         Array containing the coefficients used     (J/kmol/K)
C                  in the polynomial expressions     
C     Tref         Array containing the temperatures at which        (K)
C                  the reference enthalpies are calculated
C     href         Array containing the reference enthalpies    (J/kmol)
C     h            Enthalpy of species I                        (J/kmol)
C     J            Loop counter 
C***********************************************************************
!export this subroutine for its use in external DLLs.
!DEC$ATTRIBUTES DLLEXPORT :: ENTHALP

      COMMON/COMCP/PFCP(5,10)                                           
      COMMON/THREF/Tref(5),href(5)

      h=href(I)                                                         
      Enthalpy=0                                                            
      DO 10 J=1,10                                                      
      h=h+((PFCP(I,J)*Temp**J)-(PFCP(I,J)*Tref(I)**J))/J                
  10  CONTINUE                                                          
      Enthalpy=h                                                             

      RETURN                                                            
      END                                                               

      BLOCK DATA                                                        

      COMMON/COMCP/PFCP(5,10)                                           
      COMMON/THREF/Tref(5),href(5)
                                                                        
C1*** Coefficients are given for H2

      DATA PFCP(1,1),PFCP(1,2),PFCP(1,3),                              
     $PFCP(1,4),PFCP(1,5),PFCP(1,6),PFCP(1,7),                          
     $PFCP(1,8),PFCP(1,9),PFCP(1,10)/                                   
     $ 2.12183E+04, 4.90483E+01,-1.18908E-01, 1.50167E-04,              
     $-1.07285E-07, 4.66644E-11,-1.26418E-14, 2.08562E-18,              
     $-1.91864E-22, 7.54661E-27/                                        

C1*** Coefficients are given for O2

      DATA PFCP(2,1),PFCP(2,2),PFCP(2,3),                              
     $PFCP(2,4),PFCP(2,5),PFCP(2,6),PFCP(2,7),                          
     $PFCP(2,8),PFCP(2,9),PFCP(2,10)/                                   
     $ 3.12398E+04,-2.51025E+01, 9.50643E-02,-1.29283E-04,              
     $ 9.56020E-08,-4.25012E-11, 1.16866E-14,-1.94778E-18,              
     $ 1.80410E-22,-7.12717E-27/                                        

C1*** Coefficients are given for N2

      DATA PFCP(3,1),PFCP(3,2),PFCP(3,3),                              
     $PFCP(3,4),PFCP(3,5),PFCP(3,6),PFCP(3,7),                          
     $PFCP(3,8),PFCP(3,9),PFCP(3,10)/                                   
     $ 3.10052E+04,-1.65866E+01, 4.37297E-02,-4.10720E-05,              
     $ 2.08732E-08,-6.27548E-12, 1.11654E-15,-1.08777E-19,              
     $ 4.47487E-24, 0.E0         /                                      

C1*** Coefficients are given for CO2

      DATA PFCP(4,1),PFCP(4,2),PFCP(4,3),                              
     $PFCP(4,4),PFCP(4,5),PFCP(4,6),PFCP(4,7),                          
     $PFCP(4,8),PFCP(4,9),PFCP(4,10)/                                   
     $ 1.89318E+04, 8.20742E+01,-8.47204E-02, 5.92177E-05,              
     $-2.92546E-08, 1.01523E-11,-2.39525E-15, 3.62658E-19,              
     $-3.15882E-23, 1.19863E-27/                                        

C1*** Coefficients are given for H2O

       DATA PFCP(5,1),PFCP(5,2),PFCP(5,3),                              
     $PFCP(5,4),PFCP(5,5),PFCP(5,6),PFCP(5,7),                          
     $PFCP(5,8),PFCP(5,9),PFCP(5,10)/                                   
     $ 3.42084E+04,-1.04650E+01, 3.61342E-02,-2.73709E-05,              
     $ 1.12406E-08,-2.93883E-12, 5.25323E-16,-6.54907E-20,              
     $ 5.27765E-24,-2.04468E-28/                                        

C1*** Reference values are given for H2

      DATA Tref(1),href(1)/2.E3,6.144129E7/                                      

C1*** Reference values are given for O2

      DATA Tref(2),Href(2)/2.E3,6.7926643E7/                                     

C1*** Reference values are given for N2

      DATA Tref(3),Href(3)/2.E3,6.485353E7/                                      

C1*** Reference values are given for CO2

      DATA Tref(4),Href(4)/2.E3,-2.9253172E8/                                    

C1*** Reference values are given for H2O

      DATA Tref(5),Href(5)/2.E3,-1.5643141E8/
                                    
      END