{
 "metadata": {
  "name": "",
  "signature": "sha256:efb3cb597d2918b83a867fe2c379b3952acba398aec14a9edf762b5c40043583"
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 "worksheets": [
  {
   "cells": [
    {
     "cell_type": "heading",
     "level": 1,
     "metadata": {},
     "source": [
      "Chapter 8 - Second and third law topics"
     ]
    },
    {
     "cell_type": "heading",
     "level": 2,
     "metadata": {},
     "source": [
      "Example 1 - Pg 125"
     ]
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "#calculate the value of dp/ds at constant volume\n",
      "#Initialization of variables\n",
      "P=500 #psia\n",
      "T=700. #F\n",
      "J=778.\n",
      "#calculations\n",
      "dpds=1490 *144/J\n",
      "#results\n",
      "print '%s %d %s' %(\"dp by ds at constant volume =\",dpds,\" F/ft^3/lbm\")\n",
      "print '%s' %(\"The answer is a bit different due to rounding off error in textbook\")\n"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "dp by ds at constant volume = 275  F/ft^3/lbm\n",
        "The answer is a bit different due to rounding off error in textbook\n"
       ]
      }
     ],
     "prompt_number": 1
    },
    {
     "cell_type": "heading",
     "level": 2,
     "metadata": {},
     "source": [
      "Example 2 - Pg 131"
     ]
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "#calculate the thermal efficiency\n",
      "#Initialization of variables\n",
      "import math\n",
      "cp=0.25 #Btu/lbm R\n",
      "T0=520. #R\n",
      "T1=3460. #R\n",
      "#calculations\n",
      "dq=cp*(T0-T1)\n",
      "ds=cp*math.log(T0/T1)\n",
      "dE=dq-T0*ds\n",
      "eta=dE/dq*100.\n",
      "#results\n",
      "print '%s %.1f %s' %(\"Thermal efficiency =\",eta,\"percent\")\n"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "Thermal efficiency = 66.5 percent\n"
       ]
      }
     ],
     "prompt_number": 2
    },
    {
     "cell_type": "heading",
     "level": 2,
     "metadata": {},
     "source": [
      "Example 3 - Pg 134"
     ]
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "#calculate the Loss of available energy\n",
      "#Initialization of variables\n",
      "import math\n",
      "cp=0.25 #Btu/lbm R\n",
      "T0=520. #R\n",
      "T1=3460. #R\n",
      "dG=21069. #Btu/lbm\n",
      "dH=21502. #Btu/lbm\n",
      "#calculations\n",
      "dq=cp*(T0-T1)\n",
      "ds=cp*math.log(T0/T1)\n",
      "dE=dq-T0*ds\n",
      "eta=dE/dq\n",
      "dw=eta*dH\n",
      "de=-dG+dw\n",
      "#results\n",
      "print '%s %d %s' %(\"Loss of available energy =\",de,\"Btu/lbm\")\n"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "Loss of available energy = -6774 Btu/lbm\n"
       ]
      }
     ],
     "prompt_number": 3
    }
   ],
   "metadata": {}
  }
 ]
}