{ "metadata": { "name": "", "signature": "sha256:c59a45d9559284ebbfa4c56e2ad9c90a674f6e02433515bc489ee0db922e92e9" }, "nbformat": 3, "nbformat_minor": 0, "worksheets": [ { "cells": [ { "cell_type": "heading", "level": 1, "metadata": {}, "source": [ "Chapter 2:Molecular Diffusion In Fluids" ] }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Ex2.1: Pg-30" ] }, { "cell_type": "code", "collapsed": false, "input": [ "# Illustration 2.1\n", "\n", "# solution\n", "import math\n", "\n", "#***Data***#\n", "# a = O2 & b = CO\n", "Dab = 1.87*10**(-5);#[square m/s]\n", "Pt = 10**5;#[N/square m]\n", "z = 0.002;#[m]\n", "R = 8314;#[Nm/kmol]\n", "T = 273;#[K]\n", "Pa1 = 13*10.0**(3);#[N/square m]\n", "Pb1 = 10**(5)-13*10**(3);#[N/square m]\n", "Pa2 = 6500;#[N/square m]\n", "Pb2 = 10**(5)-6500.0;#[N/square m]\n", "#********#\n", "\n", "# Calculation from Eqn. 2.30\n", "Pbm = (Pb1-Pb2)/math.log(Pb1/Pb2);#[N/square m]\n", "Na = Dab*Pt*(Pa1-Pa2)/(R*T*z*Pbm);#[kmol/square m.s]\n", "print\" Rate of diffusion of oxygen is\",round(Na,7),\"kmol/square m.sec \"" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ " Rate of diffusion of oxygen is 2.97e-05 kmol/square m.sec \n" ] } ], "prompt_number": 8 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Ex2.2:Pg-30" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "# Illustration2.2\n", "\n", "# solution\n", "import math\n", "\n", "#***Data***#\n", "Pt = 10**5.0;#[N/square m]\n", "z = 0.002;#[m]\n", "R = 8314.0;#[Nm/kmol]\n", "T = 273;#[K]\n", "#a = O2 b = CH4 c = H2\n", "Pa1 = 13*10**(3);#[N/square m]\n", "Pb1 = 10**(5)-13*10**(3);#[N/square m]\n", "Pa2 = 6500.0;#[N/square m]\n", "Pb2 = 10.0**(5)-6500;#[N/square m]\n", "Dac = 6.99*10**(-5);#[N/square m]\n", "Dab = 1.86*10.0**(-5);#[N/square m]\n", "#*******#\n", "\n", "# Calculation from Eqn. 2.30\n", "Pbm = (Pb1-Pb2)/math.log(Pb1/Pb2);#[N/square m]\n", "Yb_prime = 2.0/(2+1);\n", "Yc_prime = 1-Yb_prime;\n", "Dam = 1.0/((Yb_prime/Dab)+(Yc_prime/Dac));#[square m.s]\n", "Na = Dam*(Pa1-Pa2)*Pt/(R*T*z*Pbm);#[kmol/square m.s]\n", "print \"Rate of diffusion is\",round(Na,7),\"kmol/square m.sec\"" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Rate of diffusion is 3.91e-05 kmol/square m.sec\n" ] } ], "prompt_number": 12 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Ex2.3:Pg-32" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "# Illustration2.3\n", "\n", "import math\n", "\n", "# solution\n", "\n", "#***Data***#\n", "# a = C2H5OH b = air\n", "Pt = 101.3*10**(3);#[N/square m]\n", "T = 273.0 ;#[K]\n", "#********#\n", "\n", "Ma = 46.07;# [kg/kmol]\n", "Mb = 29.0;# [kg/kmol]\n", "#For air from Table 2.2 (Pg 33)\n", "Eb_by_k = 78.6;# [K]\n", "rb = 0.3711; # [nm]\n", "# For C2H5OH using Eqn. 2.38 & 2.39\n", "# From Table 2.3\n", "Va = (2*0.0148)+(6*0.0037)+(0.0074);# [cubic m/kmol]\n", "Tba = 351.4;# [K]\n", "ra = 1.18*(Va**(1/3.0));#[nm]\n", "Ea_by_k = 1.21*Tba;# [K]\n", "rab = (ra+rb)/2.0;# [nm]\n", "Eab_by_k = math.sqrt(Ea_by_k*Eb_by_k);# [K]\n", "Collision_value = T/Eab_by_k;\n", "#From Fig. 2.5 (Page: 32) f(collision value)\n", "Collision_func = 0.595;\n", "Dab = (10**(-4)*(1.084-(0.249*math.sqrt((1/Ma)+(1/Mb))))*T**(3.0/2)*math.sqrt((1/Ma)+(1/Mb)))/(Pt*(rab**2)*Collision_func);#[square m/s]\n", "print\" The diffusivity of ethanol through air at 1 atm. & 0 degree C is\",round(Dab,7),\"m^2/s\"\n", "print\" The observed value from (Table 2.1) is 1.02*10^(-5) square m/s'\"" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ " The diffusivity of ethanol through air at 1 atm. & 0 degree C is 1.05e-05 m^2/s\n", " The observed value from (Table 2.1) is 1.02*10^(-5) square m/s'\n" ] } ], "prompt_number": 28 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Ex2.4:Pg-34" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "# Illustration 2.4\n", "import math\n", "\n", "# solution\n", "\n", "#***Data****#\n", "# a = acetic acid b = H2O\n", "z = 0.001;# [m]\n", "Dab = 0.95*10**(-9);#[square m/s]\n", "#************#\n", "\n", "Ma = 60.03;# [kg/kmol]\n", "Mb = 18.02;# [kg/kmol]\n", "#At 17 C & 9% solution\n", "density1 = 1012; #[kg/cubic m]\n", "Xa1 = (0.09/Ma)/((0.09/Ma)+(0.91/Mb));\n", "Xb1 = 1-Xa1;\n", "M1 = 1/((0.09/Ma)+(0.91/Mb));# [kg/kmol]\n", "#At 17 C & 3% solution\n", "density2 = 1003.2; #[kg/cubic m]\n", "Xa2 = (0.03/Ma)/((0.03/Ma)+(0.97/Mb));\n", "Xb2 = 1-Xa2;\n", "M2 = 1/((0.03/Ma)+(0.97/Mb));# [kg/kmol]\n", "avg_density_by_M = ((density1/M1)+(density2/M2))/2;#[kmol/cubic m]\n", "# From Eqn. 2.42\n", "Xbm = (Xb2-Xb1)/math.log(Xb2/Xb1);\n", "# From Eqn. 2.41\n", "Na = Dab*(avg_density_by_M)*(Xa1-Xa2)/(Xbm*z); #[square m/s]\n", "print\" The rate of diffusion is\",round(Na,9),\"square m/s\"" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ " The rate of diffusion is 1.018e-06 square m/s\n" ] } ], "prompt_number": 31 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Ex2.5:Pg-37" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "# Illustration 2.5\n", "\n", "\n", "# solution\n", "\n", "#***Data****#\n", "# a = mannitol b = H2O\n", "T = 293; # [K]\n", "#*****#\n", "\n", "Mb = 18.02;# [kg/kmol]\n", "# From Table 2.3 (Pg 33)\n", "Va = (0.0148*6)+(0.0037*14)+(0.0074*6); # [cubic m/kmol]\n", "viscosity = 0.001005; # [kg/m.s]\n", "association_factor = 2.26; # [water as a solvent]\n", "Dab = (117.3*10**(-18))*((association_factor*Mb)**0.5)*T/(viscosity*Va**0.6); # [square m/s]\n", "print\" Diffusivity of mannitol is\",round(Dab,12),\"square m/s\"\n", "print\" Observed value is 0.56*10^(-9) square m/s\"" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ " Diffusivity of mannitol is 6.01e-10 square m/s\n", " Observed value is 0.56*10^(-9) square m/s\n" ] } ], "prompt_number": 48 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Ex2.6:Pg-37" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "# Illustration 2.6\n", "\n", "\n", "# solution\n", "\n", "#****Data****#\n", "T2 = 70+273;# [K]\n", "#**********#\n", "\n", "# a = mannitol b = H2O\n", "# From Illustration 2.5 at 20 C\n", "viscosity1 = 1.005*10**(-3); # [kg/m.s]\n", "Dab1 = 0.56*10**(-9); #[m^2/s]\n", "T1 = 273+20;# [K]\n", "# At 70 C\n", "viscosity2 = 0.4061*10**(-3); # kg/m.s\n", "# Eqn. 2.44 indicates Dab*viscocity/T = constnt\n", "Dab2 = Dab1*(T2)*(viscosity1)/(T1*viscosity2);# [square m/s]\n", "print\" Diffusivity of mannitol at 70 degree C is\",round(Dab2,11),\"square/s \"\n", "print\" Observed value at 70 degree C is 1.56*10^(-9) square m/s\"" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ " Diffusivity of mannitol at 70 degree C is 1.62e-09 square/s \n", " Observed value at 70 degree C is 1.56*10^(-9) square m/s\n" ] } ], "prompt_number": 53 } ], "metadata": {} } ] }