1 !vvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvC 2 ! C 3 ! Module name: CALC_DIF_g(IER) 4 ! Purpose: Calculate the effective diffusivity of fluid phase C 5 ! C 6 ! Author:M. Syamlal Date: 13-FEB-98 C 7 ! Reviewer: Date: dd-mmm-yy C 8 ! 9 ! Updated with the dilute mixture approximation for calculation of C 10 ! multicomponent diffusion coefficients C 11 ! Author:N. Reuge Date: 11-APR-07 C 12 ! Reviewer: Date: dd-mmm-yy C 13 ! C 14 ! Literature/Document References: C 15 ! C 16 ! Variables referenced: C 17 ! Variables modified: C 18 ! C 19 ! Local variables: C 20 ! C 21 !^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^C 22 23 SUBROUTINE CALC_DIF_G() 24 !...Switches: -xf 25 !----------------------------------------------- 26 ! M o d u l e s 27 !----------------------------------------------- 28 USE param 29 USE param1 30 USE parallel 31 USE physprop 32 USE fldvar 33 USE geometry 34 USE indices 35 USE constant 36 USE scales 37 USE compar 38 USE sendrecv 39 USE run 40 USE functions 41 IMPLICIT NONE 42 !----------------------------------------------- 43 ! G l o b a l P a r a m e t e r s 44 !----------------------------------------------- 45 !----------------------------------------------- 46 ! D u m m y A r g u m e n t s 47 !----------------------------------------------- 48 49 ! Indices 50 INTEGER IJK, N 51 52 DOUBLE PRECISION Dab(3,3), Tg0, Pg0 53 54 !----------------------------------------------- 55 56 ! Default gas diffusion coefficient 57 ! Bird, Stewart, and Lightfoot (1960) -- CO2--N2 at 298.2 K 58 Dab(1,2) = 0.165D0 !cm^2/s 59 Tg0 = 298.2D0 60 Pg0 = 1.01D6 !dyne 61 62 IF(UNITS == 'SI') THEN 63 Dab(1,2) = Dab(1,2)*0.0001D0 !m^2/s 64 Pg0 = Pg0/10.D0 !Pa 65 ENDIF 66 67 68 !********Gas diffusion coef for a system of 3 species*************** 69 ! Species: SiH4, H2 & N2 70 ! Calculated using relation derived from Chapman and Enskog's theory 71 ! of gases - Reid, Prausnitz and Poling (1987) 72 73 ! Binary diffusion coefficient SiH4/H2 at 873 K 74 ! Dab(1,2) = 3.78 ! cm^2/s 75 ! Dab(2,1) = Dab(1,2) 76 77 ! Binary diffusion coefficient SiH4/N2 at 873 K 78 ! Dab(1,3) = 1.02 ! cm^2/s 79 ! Dab(3,1) = Dab(1,3) 80 81 ! Binary diffusion coefficient H2/N2 at 873 K 82 ! Dab(2,3) = 4.52 ! cm^2/s 83 ! Dab(3,2) = Dab(2,3) 84 85 ! Tg0 = 873.0 86 ! Pg0 = 1.01e6 ! dyne 87 88 ! IF(UNITS == 'SI') THEN 89 ! DO N1 = 1, NMAX(0)-1 90 ! DO N2 = N1+1, NMAX(0) 91 ! Dab(N1,N2) = Dab(N1,N2)*0.0001D0 !m^2/s 92 ! Dab(N2,N1) = Dab(N1,N2) 93 ! ENDDO 94 ! ENDDO 95 ! Pg0 = Pg0/10.D0 !Pa 96 ! ENDIF 97 98 !******************************************************************* 99 100 IF (DIF_G0 /= UNDEFINED) RETURN 101 102 !!!!$omp parallel do private(ijk) & 103 !!!!$omp& schedule(dynamic,chunk_size) 104 105 ! Default calculation of diffusivities 106 ! Influence of gas temperature and gas pressure from Fuller relation 107 DO N = 1, NMAX(0) 108 DO IJK = IJKSTART3, IJKEND3 109 IF (FLUID_AT(IJK)) THEN 110 DIF_G(IJK,N) = ROP_G(IJK)*Dab(1,2)*(T_g(IJK)/Tg0)**1.75 * & 111 Pg0/(P_g(IJK)+P_REF) 112 ELSE 113 DIF_G(IJK,N) = ZERO 114 ENDIF 115 ENDDO 116 ENDDO 117 118 119 !******************************************************************* 120 ! Caculation of diffusivities using the dilute mixture approximation for 121 ! multicomponent diffusion - Curtiss-Hirschfelder, Wilke & Blanc 122 ! Valid if the mass fraction of the carrier species > 0.9 123 124 ! Influence of gas temperature and gas pressure from Fuller relation 125 ! DO N = 1, NMAX(0) 126 ! DO IJK = IJKSTART3, IJKEND3 127 ! IF (FLUID_AT(IJK)) THEN 128 ! IF ((1.0-X_g(IJK,N)) > 1.e-8) THEN 129 ! SUMJ = ZERO 130 ! DO N2 = 1, NMAX(0) 131 ! IF (N2 /= N) SUMJ = SUMJ+X_g(IJK,N2)/Dab(N,N2) 132 ! ENDDO 133 ! DIF_G(IJK,N) = ROP_G(IJK)*(1-X_g(IJK,N))/SUMJ * & 134 ! (T_g(IJK)/Tg0)**1.75*Pg0/P_g(IJK) 135 ! ELSE 136 ! DIF_G(IJK,N) = ROP_G(IJK)*Dab(1,2) 137 ! ENDIF 138 ! ELSE 139 ! DIF_G(IJK,N) = ZERO 140 ! ENDIF 141 ! ENDDO 142 ! ENDDO 143 !**************************************************************************** 144 145 146 RETURN 147 END SUBROUTINE CALC_DIF_G 148 149