{ "metadata": { "name": "", "signature": "sha256:f1d828103bb270e68cac7fea789e3b42ea64320d86ed9fcc67d96c498216f06e" }, "nbformat": 3, "nbformat_minor": 0, "worksheets": [ { "cells": [ { "cell_type": "heading", "level": 1, "metadata": {}, "source": [ "Chapter 2 : The first law of Thermodynamics" ] }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 2.1 pg : 37" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\t\t\t\n", "# Variables\n", "P1 = 200. \t\t\t#psia\n", "P2 = 15. \t\t\t#psia\n", "V1 = 1. \t\t\t#ft**3\n", "g = 1.3\n", "\t\t\t\n", "# Calculations\n", "V2 = V1*(P1/P2)**(1/g)\n", "W = -(144*(P2*V2 - P1*V1)/(g-1))\n", "\t\t\t\n", "# Results\n", "print \"Work done = %.2e ft. lbf\"%(W)\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Work done = 4.32e+04 ft. lbf\n" ] } ], "prompt_number": 1 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 2.2 pg : 37" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\t\t\t\n", "# Variables\n", "L = 0.305 \t\t\t#m\n", "v = 4.58 \t\t\t#m/s\n", "i = 10. \t\t\t#A\n", "B = 1. \t\t\t#W/m**2\n", "\t\t\t\n", "# Calculations\n", "F = i*B*L\n", "W = F*v\n", "\t\t\t\n", "# Results\n", "print \"Force necessary = %.2f N\"%(F)\n", "print \" Work per unit time = %.2f W\"%(W)\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Force necessary = 3.05 N\n", " Work per unit time = 13.97 W\n" ] } ], "prompt_number": 2 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 2.3 pg : 45" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\t\t\t\n", "# Variables\n", "U = 2545. \t\t\t#B/hr\n", "m = 50. \t\t\t#lbm\n", "cv = 1.\n", "\t\t\t\n", "# Calculations\n", "dT = U/(m*cv)\n", "\t\t\t\n", "# Results\n", "print \"Change in temperature = %.1f F\"%(dT)\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Change in temperature = 50.9 F\n" ] } ], "prompt_number": 3 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 2.4 pg : 46" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\t\t\t\n", "# Variables\n", "P1 = 14.7 \t\t\t#psia\n", "V1 = 1. \t\t\t#ft**3\n", "P2 = 14.7 \t\t\t#psia\n", "M = 28.97\n", "T1 = 70.+460 \t\t\t#R\n", "T2 = 500.+460 \t\t\t#R\n", "cp = 0.24 \t\t\t#B/lbm F\n", "\t\t\t\n", "# Calculations\n", "m = P1*144*V1*M/(1545*T1)\n", "Qp = m*cp*(T2-T1)\n", "V2 = V1*P1*T2/(P2*T1)\n", "\n", "W = P1*144*(V2-V1)\n", "W = -W/778\n", "dU = Qp+W\n", "\t\t\t\n", "# Results\n", "print \"Work done = %.2f Btu\"%(W)\n", "print \" Heat added = %.2f Btu\"%(Qp)\n", "print \" Change in internal energy = %.2f Btu\"%(dU)\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Work done = -2.21 Btu\n", " Heat added = 7.73 Btu\n", " Change in internal energy = 5.52 Btu\n" ] } ], "prompt_number": 5 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 2.5 pg : 47" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\t\t\t\n", "# Variables\n", "l = 20. \n", "b = 25.\n", "h = 8.\n", "Vp = 2.5\n", "n = 20.\n", "P = 14.7 \t\t\t#psia\n", "T = 530. \t \t\t#R\n", "t = 15. \t\t \t#min\n", "Qp = 375. \t\t\t #B/hr\n", "cv = 0.1715 \t\t\t#B/lbm F\n", "\t\t\t\n", "# Calculations\n", "Vroom = l*b*h\n", "Vair = Vroom-Vp*n\n", "m = P*Vair*144/(53.35*T)\n", "dU = n*Qp\n", "U = t*dU/60\n", "dT = U/(m*cv)\n", "\t\t\t\n", "# Results\n", "print \"Air temperature rise = %d F\"%(dT+1)\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Air temperature rise = 37 F\n" ] } ], "prompt_number": 6 } ], "metadata": {} } ] }