[e200b7a] | 1 | subroutine part0(dquer,dsigma,density,fract,schmi,cun,vsh) |
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| 2 | ! i i i o o o o |
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| 3 | !***************************************************************************** |
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| 4 | ! * |
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| 5 | ! Calculation of time independent factors of the dry deposition of * |
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| 6 | ! particles: * |
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| 7 | ! Log-Normal-distribution of mass [dM/dlog(dp)], unimodal * |
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| 8 | ! * |
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| 9 | ! AUTHOR: Matthias Langer, adapted by Andreas Stohl, 13 November 1993 * |
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| 10 | ! * |
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| 11 | ! Literature: * |
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| 12 | ! [1] Scire/Yamartino/Carmichael/Chang (1989), * |
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| 13 | ! CALGRID: A Mesoscale Photochemical Grid Model. * |
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| 14 | ! Vol II: User's Guide. (Report No.A049-1, June, 1989) * |
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| 15 | ! * |
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| 16 | !***************************************************************************** |
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| 17 | ! * |
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| 18 | ! Variables: * |
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| 19 | ! alpha help variable * |
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| 20 | ! cun 'slip-flow' correction after Cunningham * |
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| 21 | ! d01 [um] upper diameter * |
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| 22 | ! d02 [um] lower diameter * |
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| 23 | ! dc [m2/s] coefficient of Brownian diffusion * |
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| 24 | ! delta distance given in standard deviation units * |
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| 25 | ! density [kg/m3] density of the particle * |
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| 26 | ! dmean geometric mean diameter of interval * |
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| 27 | ! dquer [um] geometric mass mean particle diameter * |
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| 28 | ! dsigma e.g. dsigma=10 or dsigma=0.1 means that 68% of the mass * |
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| 29 | ! are between 0.1*dquer and 10*dquer * |
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| 30 | ! fract(ni) mass fraction of each diameter interval * |
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| 31 | ! kn Knudsen number * |
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| 32 | ! ni number of diameter intervals, for which deposition * |
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| 33 | ! is calculated * |
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| 34 | ! schmidt Schmidt number * |
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| 35 | ! schmi schmidt**2/3 * |
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| 36 | ! vsh [m/s] gravitational settling velocity of the particle * |
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| 37 | ! x01 normalized upper diameter * |
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| 38 | ! x02 normalized lower diameter * |
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| 39 | ! * |
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| 40 | ! Constants: * |
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| 41 | ! g [m/s2] Acceleration of gravity * |
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| 42 | ! kb [J/K] Stefan-Boltzmann constant * |
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| 43 | ! lam [m] mean free path of air molecules * |
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| 44 | ! myl [kg/m/s] dynamical viscosity of air * |
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| 45 | ! nyl [m2/s] kinematic viscosity of air * |
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| 46 | ! tr reference temperature * |
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| 47 | ! * |
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| 48 | ! Function: * |
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| 49 | ! erf calculates the integral of the Gauss function * |
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| 50 | ! * |
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| 51 | !***************************************************************************** |
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| 52 | |
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| 53 | use par_mod |
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| 54 | |
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| 55 | implicit none |
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| 56 | |
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| 57 | real,parameter :: tr=293.15 |
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| 58 | |
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| 59 | integer :: i |
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| 60 | real :: dquer,dsigma,density,xdummy,d01,d02,delta,x01,x02,fract(ni) |
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| 61 | real :: dmean,alpha,cun,dc,schmidt,schmi(ni),vsh(ni),kn,erf |
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| 62 | real,parameter :: myl=1.81e-5,nyl=0.15e-4 |
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| 63 | real,parameter :: lam=6.53e-8,kb=1.38e-23,eps=1.2e-38 |
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| 64 | |
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| 65 | |
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| 66 | ! xdummy constant for all intervals |
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| 67 | !********************************** |
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| 68 | |
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| 69 | xdummy=sqrt(2.)*alog(dsigma) |
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| 70 | |
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| 71 | |
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| 72 | ! particles diameters are split up to ni intervals between |
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| 73 | ! dquer-3*dsigma and dquer+3*dsigma |
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| 74 | !********************************************************* |
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| 75 | |
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| 76 | delta=6./real(ni) |
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| 77 | |
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| 78 | d01=dquer*dsigma**(-3) |
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| 79 | do i=1,ni |
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| 80 | d02=d01 |
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| 81 | d01=dquer*dsigma**(-3.+delta*real(i)) |
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| 82 | x01=alog(d01/dquer)/xdummy |
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| 83 | x02=alog(d02/dquer)/xdummy |
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[07c3e71] | 84 | !print*,'part0:: d02=' , d02 , 'd01=', d01 |
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[e200b7a] | 85 | |
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| 86 | ! Area under Gauss-function is calculated and gives mass fraction of interval |
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| 87 | !**************************************************************************** |
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| 88 | |
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| 89 | fract(i)=0.5*(erf(x01)-erf(x02)) |
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[07c3e71] | 90 | !print*,'part0:: fract(',i,')', fract(i) |
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| 91 | !print*,'part0:: fract', fract(i), x01, x02, erf(x01), erf(x02) |
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[e200b7a] | 92 | |
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| 93 | ! Geometric mean diameter of interval in [m] |
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| 94 | !******************************************* |
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| 95 | |
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| 96 | dmean=1.E-6*exp(0.5*alog(d01*d02)) |
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[07c3e71] | 97 | !print*,'part0:: dmean=', dmean |
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[e200b7a] | 98 | |
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| 99 | ! Calculation of time independent parameters of each interval |
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| 100 | !************************************************************ |
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| 101 | |
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| 102 | kn=2.*lam/dmean |
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| 103 | if ((-1.1/kn).le.log10(eps)*log(10.)) then |
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| 104 | alpha=1.257 |
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| 105 | else |
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| 106 | alpha=1.257+0.4*exp(-1.1/kn) |
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| 107 | endif |
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| 108 | cun=1.+alpha*kn |
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| 109 | dc=kb*tr*cun/(3.*pi*myl*dmean) |
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| 110 | schmidt=nyl/dc |
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| 111 | schmi(i)=schmidt**(-2./3.) |
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| 112 | vsh(i)=ga*density*dmean*dmean*cun/(18.*myl) |
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| 113 | |
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[07c3e71] | 114 | !print*,'part0:: vsh(',i,')', vsh(i) |
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| 115 | |
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[e200b7a] | 116 | end do |
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| 117 | |
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[07c3e71] | 118 | !stop 'part0' |
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| 119 | |
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[e200b7a] | 120 | end subroutine part0 |
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