wrfv2_fire/chem/KPP/kpp/kpp-2.1/util/WRF_conform/WRFUserRateLaws.f90

   1 !~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   2 !  User-defined Rate Law functions
   3 !  Note: the default argument type for rate laws, as read from the equations file, is single precision
   4 !        but all the internal calculations are performed in double precision
   5 !~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   6
   7 !~~~> Simplified Arrhenius, with two arguments
   8    KPP_REAL FUNCTION ARR2( A0,B0, TEMP )
   9       REAL(KIND=dp) :: TEMP
  10       REAL A0,B0
  11       ARR2 = A0 * EXP( REAL(-B0, KIND=dp)/TEMP )
  12    END FUNCTION ARR2
  13
  14
  15 !------------------------------------
  16 ! Troe reactions (as in Stockwell et al, 1997)
  17
  18     KPP_REAL FUNCTION TROE(k0_300K,n,kinf_300K,m,temp,cair)
  19
  20     INTRINSIC LOG10
  21
  22     REAL(KIND=dp), INTENT(IN) :: temp      ! temperature [K]
  23     REAL(KIND=dp), INTENT(IN) :: cair      ! air concentration [molecules/cm3]
  24     REAL,          INTENT(IN) :: k0_300K   ! low pressure limit at 300 K
  25     REAL,          INTENT(IN) :: n         ! exponent for low pressure limit
  26     REAL,          INTENT(IN) :: kinf_300K ! high pressure limit at 300 K
  27     REAL,          INTENT(IN) :: m         ! exponent for high pressure limit
  28     REAL(KIND=dp)             :: zt_help, k0_T, kinf_T, k_ratio
  29
  30     zt_help = 300._dp/temp
  31     k0_T    = k0_300K   * zt_help**(n) * cair ! k_0   at current T
  32     kinf_T  = kinf_300K * zt_help**(m)        ! k_inf at current T
  33     k_ratio = k0_T/kinf_T
  34     TROE   = k0_T/(1._dp+k_ratio)*0.6_dp**(1._dp/(1._dp+LOG10(k_ratio)**2))
  35
  36    END FUNCTION TROE
  37
  38
  39
  40 !-------------------------------------------
  41 ! Troe equilibrium reactions (as in Stockwell et al, 1997)
  42
  43     KPP_REAL FUNCTION TROEE(A, B, k0_300K,n,kinf_300K,m,temp,cair)
  44
  45     INTRINSIC LOG10
  46
  47     REAL(dp), INTENT(IN) :: temp      ! temperature [K]
  48     REAL(dp), INTENT(IN) :: cair      ! air concentration [molecules/cm3]
  49     REAL,     INTENT(IN) :: k0_300K   ! low pressure limit at 300 K
  50     REAL,     INTENT(IN) :: n         ! exponent for low pressure limit
  51     REAL,     INTENT(IN) :: kinf_300K ! high pressure limit at 300 K
  52     REAL,     INTENT(IN) :: m         ! exponent for high pressure limit
  53     REAL,     INTENT(IN) :: A, B
  54     REAL(dp)             :: zt_help, k0_T, kinf_T, k_ratio, troe
  55
  56
  57     zt_help = 300._dp/temp
  58     k0_T    = k0_300K   * zt_help**(n) * cair ! k_0   at current T
  59     kinf_T  = kinf_300K * zt_help**(m)        ! k_inf at current T
  60     k_ratio = k0_T/kinf_T
  61     troe   = k0_T/(1._dp+k_ratio)*0.6_dp**(1._dp/(1._dp+LOG10(k_ratio)**2))
  62
  63     TROEE = A * EXP( -REAL(B, KIND=dp) / temp) * troe
  64
  65
  66
  67   END FUNCTION TROEE
  68
  69 !------------------------
  70 ! k=T^2 C exp (-D/T) reactions
  71
  72    KPP_REAL FUNCTION THERMAL_T2(c, d ,temp)
  73     REAL(dp), INTENT(IN) :: temp      ! temperature [K]
  74     REAL,     INTENT(IN) :: c, d
  75
  76
  77      THERMAL_T2= temp**2._dp * c * EXP(-REAL(d, KIND=dp)/temp)
  78
  79    END FUNCTION THERMAL_T2
  80
  81 !~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  82 !  End of User-defined Rate Law functions
  83 !~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~