{ "metadata": { "name": "", "signature": "sha256:d5accb40ab200594c5bee653d2ffb7fee1e29e674b04c22a54296f7e8cb68080" }, "nbformat": 3, "nbformat_minor": 0, "worksheets": [ { "cells": [ { "cell_type": "heading", "level": 1, "metadata": {}, "source": [ "Chapter 9 : Kinetic theory and transport\n", "phenomena" ] }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 9.1 pg : 232" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\t\t\t\n", "# Variables\n", "import math \n", "N0 = 6.025*10**26\n", "M = 32.\n", "k = 1.38*10**-23\n", "T = 300. \t\t\t#K\n", "\t\t\t\n", "# Calculations\n", "m = M/N0\n", "vavg = math.sqrt(8*k*T/(math.pi*m))\n", "vrms = math.sqrt(3*k*T/m)\n", "vm = math.sqrt(2*k*T/m)\n", "\t\t\t\n", "# Results\n", "print \"Average velocity = %d m/sec\"%(vavg)\n", "print \" RMS velocity = %d m/sec\"%(vrms)\n", "print \" Most probable velocity = %.f m/sec\"%(vm)\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Average velocity = 445 m/sec\n", " RMS velocity = 483 m/sec\n", " Most probable velocity = 395 m/sec\n" ] } ], "prompt_number": 2 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 9.2 pg : 233" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\t\t\t\n", "# Variables\n", "import math \n", "T = 300. \t\t\t#K\n", "dv = 0.02\n", "vm = 395. \t\t\t#m/s\n", "m = 5.32*10**-26 \t\t\t#kg\n", "k = 1.38*10**-23\n", "vrms = 483. \t\t\t#m/s\n", "\t\t\t\n", "# Calculations\n", "N1 = math.sqrt(2/math.pi) *(m/(k*T))**(3./2) *vm**2 *math.exp(-1) *dv*vm\n", "N2 = math.sqrt(2/math.pi) *(m/(k*T))**(3./2) *vrms**2 *math.exp(-3/2) *dv*vrms\n", "\t\t\t\n", "# Results\n", "print \"Fraction of oxygen molecules at v most probable speed = %.4f \"%(N1)\n", "print \" Fraction of oxygen molecules at v rms speed = %.4f \"%(N2)\n", "\n", "# rounding off error" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Fraction of oxygen molecules at v most probable speed = 0.0167 \n", " Fraction of oxygen molecules at v rms speed = 0.0112 \n" ] } ], "prompt_number": 4 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 9.3 pg : 236" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\t\t\t\n", "# Variables\n", "p = 1.013*10**5 \t\t\t#N/m**2\n", "k = 1.38*10**-23\n", "T = 300. \t \t\t#K\n", "v = 445. \t \t \t#m/s\n", "A = 0.001*10**-6 \t\t\t#m**2\n", "\t\t\t\n", "# Calculations\n", "n = p/(k*T)\n", "J = n*v/4\n", "escaping = J*A\n", "\t\t\t\n", "# Results\n", "print \"No. of molecules escaping per unit time = %.2e mol/sec\"%(escaping)\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "No. of molecules escaping per unit time = 2.72e+18 mol/sec\n" ] } ], "prompt_number": 5 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 9.4 pg : 239" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\t\t\t\n", "# Variables\n", "import math \n", "d = 3.5*10**-10 \t\t\t#m\n", "n = 2.45*10**25\n", "\t\t\t\n", "# Calculations\n", "sig = math.pi*d**2\n", "lambda_ = 1./(math.sqrt(2) *sig*n) \n", "frac = math.exp(-2)\n", "\t\t\t\n", "# Results\n", "print \"Mean free path = %.2e m\"%(lambda_)\n", "print \" fraction of molecules = %.3f\"%(frac)\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Mean free path = 7.50e-08 m\n", " fraction of molecules = 0.135\n" ] } ], "prompt_number": 6 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 9.5 pg : 244" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\t\t\t\n", "# Variables\n", "P = 1. \t \t\t#atm\n", "T = 300. \t\t\t#K\n", "\t\t\t\n", "# Calculations\n", "cv = 4.97\n", "vavg = 1580. \t\t\t#ft/s\n", "sig = 4.13*10**-18 \t\t\t#ft**2\n", "N0 = 6.025*10**26 *0.4536\n", "K = vavg*3600.*cv/(3*N0*sig)\n", "\t\t\t\n", "# Results\n", "print \"Thermal conductivity = %.2e B/hr ft F\"%(K)\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Thermal conductivity = 8.35e-03 B/hr ft F\n" ] } ], "prompt_number": 7 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 9.6 pg : 245" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\t\t\t\n", "# Variables\n", "m = 5.32*10**-26 \t\t\t#kg\n", "v = 445. \t \t\t#m/s\n", "sigma = 3.84*10**-19 \t\t\t#m**2\n", "\t\t\t\n", "# Calculations\n", "mu = m*v/(3*sigma)\n", "\t\t\t\n", "# Results\n", "print \"Dynamic viscosity of oxygen = %.2e newton sec/m**2\"%(mu)\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Dynamic viscosity of oxygen = 2.06e-05 newton sec/m**2\n" ] } ], "prompt_number": 1 } ], "metadata": {} } ] }