chem/KPP/kpp/kpp-2.1/util/UserRateLaws.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 !~~~>  Arrhenius
   8    KPP_REAL FUNCTION ARR( A0,B0,C0 )
   9       REAL A0,B0,C0
  10       ARR =  DBLE(A0) * EXP(-DBLE(B0)/TEMP) * (TEMP/300.0_dp)**DBLE(C0)
  11    END FUNCTION ARR
  12
  13 !~~~> Simplified Arrhenius, with two arguments
  14 !~~~> Note: The argument B0 has a changed sign when compared to ARR
  15    KPP_REAL FUNCTION ARR2( A0,B0 )
  16       REAL A0,B0
  17       ARR2 =  DBLE(A0) * EXP( DBLE(B0)/TEMP )
  18    END FUNCTION ARR2
  19
  20    KPP_REAL FUNCTION EP2(A0,C0,A2,C2,A3,C3)
  21       REAL A0,C0,A2,C2,A3,C3
  22       REAL(dp) K0,K2,K3
  23       K0 = DBLE(A0) * EXP(-DBLE(C0)/TEMP)
  24       K2 = DBLE(A2) * EXP(-DBLE(C2)/TEMP)
  25       K3 = DBLE(A3) * EXP(-DBLE(C3)/TEMP)
  26       K3 = K3*CFACTOR*1.0E6_dp
  27       EP2 = K0 + K3/(1.0_dp+K3/K2 )
  28    END FUNCTION EP2
  29
  30    KPP_REAL FUNCTION EP3(A1,C1,A2,C2)
  31       REAL A1, C1, A2, C2
  32       REAL(dp) K1, K2
  33       K1 = DBLE(A1) * EXP(-DBLE(C1)/TEMP)
  34       K2 = DBLE(A2) * EXP(-DBLE(C2)/TEMP)
  35       EP3 = K1 + K2*(1.0E6_dp*CFACTOR)
  36    END FUNCTION EP3
  37
  38    KPP_REAL FUNCTION FALL ( A0,B0,C0,A1,B1,C1,CF)
  39       REAL A0,B0,C0,A1,B1,C1,CF
  40       REAL(dp) K0, K1
  41       K0 = DBLE(A0) * EXP(-DBLE(B0)/TEMP)* (TEMP/300.0_dp)**DBLE(C0)
  42       K1 = DBLE(A1) * EXP(-DBLE(B1)/TEMP)* (TEMP/300.0_dp)**DBLE(C1)
  43       K0 = K0*CFACTOR*1.0E6_dp
  44       K1 = K0/K1
  45       FALL = (K0/(1.0_dp+K1))*   &
  46            DBLE(CF)**(1.0_dp/(1.0_dp+(LOG10(K1))**2))
  47    END FUNCTION FALL
  48
  49   !---------------------------------------------------------------------------
  50
  51   ELEMENTAL REAL(dp) FUNCTION k_3rd(temp,cair,k0_300K,n,kinf_300K,m,fc)
  52
  53     INTRINSIC LOG10
  54
  55     REAL(dp), INTENT(IN) :: temp      ! temperature [K]
  56     REAL(dp), INTENT(IN) :: cair      ! air concentration [molecules/cm3]
  57     REAL,     INTENT(IN) :: k0_300K   ! low pressure limit at 300 K
  58     REAL,     INTENT(IN) :: n         ! exponent for low pressure limit
  59     REAL,     INTENT(IN) :: kinf_300K ! high pressure limit at 300 K
  60     REAL,     INTENT(IN) :: m         ! exponent for high pressure limit
  61     REAL,     INTENT(IN) :: fc        ! broadening factor (usually fc=0.6)
  62     REAL                 :: zt_help, k0_T, kinf_T, k_ratio
  63
  64     zt_help = 300._dp/temp
  65     k0_T    = k0_300K   * zt_help**(n) * cair ! k_0   at current T
  66     kinf_T  = kinf_300K * zt_help**(m)        ! k_inf at current T
  67     k_ratio = k0_T/kinf_T
  68     k_3rd   = k0_T/(1._dp+k_ratio)*fc**(1._dp/(1._dp+LOG10(k_ratio)**2))
  69
  70   END FUNCTION k_3rd
  71
  72   !---------------------------------------------------------------------------
  73
  74   ELEMENTAL REAL(dp) FUNCTION k_arr (k_298,tdep,temp)
  75     ! Arrhenius function
  76
  77     REAL,     INTENT(IN) :: k_298 ! k at T = 298.15K
  78     REAL,     INTENT(IN) :: tdep  ! temperature dependence
  79     REAL(dp), INTENT(IN) :: temp  ! temperature
  80
  81     INTRINSIC EXP
  82
  83     k_arr = k_298 * EXP(tdep*(1._dp/temp-3.3540E-3_dp)) ! 1/298.15=3.3540e-3
  84
  85   END FUNCTION k_arr
  86
  87 !~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  88 !  End of User-defined Rate Law functions
  89 !~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~