{ "metadata": { "name": "" }, "nbformat": 3, "nbformat_minor": 0, "worksheets": [ { "cells": [ { "cell_type": "heading", "level": 1, "metadata": {}, "source": [ "Chapter 8 - Basic Applications of the Second Law" ] }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 1 - Pg 130" ] }, { "cell_type": "code", "collapsed": false, "input": [ "#calculate the Max Efficiency possible\n", "#initialization of varaibles\n", "T1=85+460. #R\n", "T2=50+460. #R\n", "#calculations\n", "eta=(T1-T2)/T1\n", "#results\n", "print '%s %.1f %s' %(\"Max. efficiency =\",eta*100,\"percent\")\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Max. efficiency = 6.4 percent\n" ] } ], "prompt_number": 1 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 2 - Pg 130" ] }, { "cell_type": "code", "collapsed": false, "input": [ "#calculate the Max Efficiency possible\n", "#initialization of varaibles\n", "T1=1050+460. #R\n", "T2=90+460. #R\n", "#calculations\n", "eta=(T1-T2)/T1\n", "#results\n", "print '%s %d %s' %(\"Max. possible efficiency = \",eta*100,\"percent\")\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Max. possible efficiency = 63 percent\n" ] } ], "prompt_number": 2 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 3 - Pg 130" ] }, { "cell_type": "code", "collapsed": false, "input": [ "#calculate the change in entropy\n", "#initialization of varaibles\n", "import math\n", "T1=50+460. \t#R\n", "T2=150+460. #R\n", "m=1.\n", "cp=0.240\n", "#calculations\n", "ds=m*cp*(math.log(T2) - math.log(T1))\n", "#results\n", "print '%s %.4f %s' %(\"Change in entropy =\",ds,\"B/ F abs\")\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Change in entropy = 0.0430 B/ F abs\n" ] } ], "prompt_number": 3 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 4 - Pg 131" ] }, { "cell_type": "code", "collapsed": false, "input": [ "#calculate the change in entropy\n", "#initialization of varaibles\n", "import math\n", "T1=50+460. #R\n", "T2=150+460. #R\n", "m=1\n", "cp=0.240\n", "#calculations\n", "ds=m*cp*(math.log(T2) - math.log(T1))\n", "#results\n", "print '%s %.4f %s' %(\"Change in entropy = \",ds,\"B/ F abs\")\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Change in entropy = 0.0430 B/ F abs\n" ] } ], "prompt_number": 4 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 5 - Pg 131" ] }, { "cell_type": "code", "collapsed": false, "input": [ "#Calculate the total change in entropy\n", "#initialization of varaibles\n", "import math\n", "Q=826. #B/lb\n", "T=860. #R\n", "T1=2000+460. #R\n", "T2=1000+460. #R\n", "#calculations\n", "ds=Q/T\n", "dsgas=Q*(math.log(T2)-math.log(T1))/(T1-T2)\n", "dst=ds+dsgas\n", "#results\n", "print '%s %.3f %s' %(\"Total entropy change =\",dst,\"B/R\")\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Total entropy change = 0.530 B/R\n" ] } ], "prompt_number": 5 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 6 - Pg 132" ] }, { "cell_type": "code", "collapsed": false, "input": [ "#Calculate the loss in energy and increase in unavailable energy\n", "#initialization of varaibles\n", "T0=540. #R\n", "Q=826. #B/lb\n", "ds=0.534\n", "ds2=0.431\n", "#calculations\n", "tds=T0*ds\n", "tds2=T0*ds2\n", "H=Q-tds2\n", "Loss=tds/H\n", "#results\n", "print '%s %.1f %s' %(\"Increase in unavailable energy = \",tds,\"Btu\")\n", "print '%s %.1f %s' %(\"Loss =\",Loss*100,\"percent\")\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Increase in unavailable energy = 288.4 Btu\n", "Loss = 48.6 percent\n" ] } ], "prompt_number": 4 } ], "metadata": {} } ] }