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  {
   "cells": [
    {
     "cell_type": "heading",
     "level": 1,
     "metadata": {},
     "source": [
      "Chapter 4 : Entropy"
     ]
    },
    {
     "cell_type": "heading",
     "level": 2,
     "metadata": {},
     "source": [
      "Example 4.1 Page No : 6"
     ]
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "\t\t\t\n",
      "# Variables :\n",
      "T1 = 400.;\t\t\t#Kelvin\n",
      "T2 = 300.;\t\t\t#Kelvin\n",
      "Q1 = 4800.;\t\t\t#KJ\n",
      "Q2 = -4800.;\t\t\t#KJ\n",
      "\n",
      "# Calculations\n",
      "#Q1/T1+Q2/T2< = 0\n",
      "LHS = Q1/T1+Q2/T2;\t\t\t#\n",
      "\n",
      "# Results\n",
      "print \"/T1+Q2/T2  =  \",LHS\n",
      "print (\"It is less than zero. Process is irreversible\")\n"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "/T1+Q2/T2  =   -4.0\n",
        "It is less than zero. Process is irreversible\n"
       ]
      }
     ],
     "prompt_number": 1
    },
    {
     "cell_type": "heading",
     "level": 2,
     "metadata": {},
     "source": [
      "Example 4.2 Page No : 6"
     ]
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "\t\t\t\n",
      "# Variables :\n",
      "T1 = 290.+273;\t\t\t#Kelvin\n",
      "T2 = 8.5+273;\t\t\t#Kelvin\n",
      "Q1 = 300.;\t\t\t#KJ\n",
      "#Case 1 :\n",
      "Q2 = -215.;\t\t\t#KJ\n",
      "\n",
      "# Calculations and Results\n",
      "sigmaQbyT = Q1/T1+Q2/T2\n",
      "print \"(i) Q1/T1+Q2/T2  =  %.4f\"%sigmaQbyT\n",
      "print (\"It is less than zero. Cycle is irreversible\")\n",
      "\n",
      "#Case 2 :\n",
      "Q2 = -150.;\t\t\t#KJ\n",
      "sigmaQbyT = Q1/T1+Q2/T2\n",
      "print \"(ii) Q1/T1+Q2/T2  =  %.0f\"%sigmaQbyT\n",
      "print (\"It is equal to zero. Cycle is reversible\");\n",
      "#Case 3 :\n",
      "Q2 = -75.;\t\t\t#KJ\n",
      "sigmaQbyT = Q1/T1+Q2/T2\n",
      "print \"(iii) Q1/T1+Q2/T2  =  %.4f\"%sigmaQbyT\n",
      "print (\"It is greater than zero. Cycle is impossible.\");\n"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "(i) Q1/T1+Q2/T2  =  -0.2309\n",
        "It is less than zero. Cycle is irreversible\n",
        "(ii) Q1/T1+Q2/T2  =  0\n",
        "It is equal to zero. Cycle is reversible\n",
        "(iii) Q1/T1+Q2/T2  =  0.2664\n",
        "It is greater than zero. Cycle is impossible.\n"
       ]
      }
     ],
     "prompt_number": 1
    },
    {
     "cell_type": "heading",
     "level": 2,
     "metadata": {},
     "source": [
      "Example 4.3 Page No : 18"
     ]
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "import math \n",
      "\t\t\t\n",
      "# Variables :\n",
      "V1 = 10.;\t\t\t#m**3\n",
      "T1 = 175.+273;\t\t\t#Kelvin\n",
      "T2 = 36.+273;\t\t\t#Kelvin\n",
      "p1 = 5.;\t\t\t#bar\n",
      "p2 = 1.;\t\t\t#bar\n",
      "R = 287.;\t\t\t#KJ/KgK\n",
      "Cp = 1.005;\t\t\t#KJ/KgK\n",
      "\n",
      "# Calculations\n",
      "#p*V = m*R*T\n",
      "m = p1*10**5*V1/R/T1;\t\t\t#Kg\n",
      "deltaS = m*Cp*math.log(T2/T1)+m*R/1000*math.log(p1/p2);\t\t\t#KJ/K\n",
      "\n",
      "# Results\n",
      "print \"Entropy change in KJ/K :  %.3f\"%deltaS\n"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "Entropy change in KJ/K :  3.445\n"
       ]
      }
     ],
     "prompt_number": 2
    },
    {
     "cell_type": "heading",
     "level": 2,
     "metadata": {},
     "source": [
      "Example 4.4 Page No : 18"
     ]
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "\t\t\t\n",
      "# Variables :\n",
      "deltaS = 5.;\t\t\t#KJ/KgK\n",
      "W = 2000.;\t\t\t#KJ/Kg\n",
      "T1 = 327.+273;\t\t\t#Kelvin\n",
      "\n",
      "# Calculations and Results\n",
      "Q1 = deltaS*T1;\t\t\t#KJ/Kg\n",
      "Q2 = Q1-W;\t\t\t#KJ/Kg\n",
      "Eta = W/Q1*100;\t\t\t#%\n",
      "print \"Efficiency in %% : %.1f\"%Eta\n",
      "\n",
      "T2 = Q2/Q1*T1;\t\t\t#K\n",
      "print \"Lowest temperature in Kelvin : \",T2\n"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "Efficiency in % : 66.7\n",
        "Lowest temperature in Kelvin :  200.0\n"
       ]
      }
     ],
     "prompt_number": 4
    },
    {
     "cell_type": "heading",
     "level": 2,
     "metadata": {},
     "source": [
      "Example 4.5 Page No : 19"
     ]
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "import scipy\n",
      "from scipy.integrate import quad \n",
      "\t\t\t\n",
      "# Variables :\n",
      "mc = 0.5;\t\t\t#Kg\n",
      "Tc = 100.+273;\t\t\t#K\n",
      "Cpc = 0.393;\t\t\t#KJ/KgK\n",
      "Tw = 10.+273;\t\t\t#K\n",
      "Cpw = 4.2;\t\t\t#KJ/KgK\n",
      "\n",
      "# Calculations and Results\n",
      "def f0(T): \n",
      "\t return mc*Cpc\n",
      "\n",
      "Q =  quad(f0,Tc,Tw)[0]\n",
      "\n",
      "def f1(T): \n",
      "\t return mc*Cpc/T\n",
      "\n",
      "deltaSc =  quad(f1,Tc,Tw)[0]\n",
      "\n",
      "deltaSw = abs(Q)/Tw;\t\t\t#KJ/K\n",
      "deltaSuniverse = deltaSc+deltaSw;\t\t\t#Kj/K\n",
      "print \"Part (i) Chane in entropy in KJ/K : %.4f\"%deltaSuniverse\n",
      "\n",
      "T1 = 383.;\t\t\t#K\n",
      "T2 = 283.;\t\t\t#K\n",
      "T = (T1+T2)/2;\t\t\t#K\n",
      "\n",
      "def f2(T): \n",
      "\t return 1/T\n",
      "a = quad(f2,T1,T)[0]\n",
      "deltaSuniverse = mc*Cpc*( a + 0.1627)\n",
      "print \"Part (ii) Chane in entropy in KJ/K : %.5f\"%deltaSuniverse\n"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "Part (i) Chane in entropy in KJ/K : 0.0082\n",
        "Part (ii) Chane in entropy in KJ/K : 0.00448\n"
       ]
      }
     ],
     "prompt_number": 5
    },
    {
     "cell_type": "heading",
     "level": 2,
     "metadata": {},
     "source": [
      "Example 4.6 Page No : 20"
     ]
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "\n",
      "# Variables :\n",
      "Tc = 35.+273;\t\t\t#K\n",
      "W = 500.;\t\t\t#KJ\n",
      "T1 = 308.;\t\t\t#K\n",
      "T2 = 308.;\t\t\t#K\n",
      "T0 = 15.+273;\t\t\t#K\n",
      "Q = W;\t    \t\t#KJ\n",
      "deltaS1 = 0;\t\t\t#as heat supplied is zero\n",
      "\n",
      "# Calculations\n",
      "deltaS2 = Q/T0;\t\t\t#KJ/K\n",
      "\n",
      "# Results\n",
      "print \"Change in entropy in KJ/K : %.4f\"%deltaS2\n"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "Change in entropy in KJ/K : 1.7361\n"
       ]
      }
     ],
     "prompt_number": 6
    },
    {
     "cell_type": "heading",
     "level": 2,
     "metadata": {},
     "source": [
      "Example 4.7 Page No : 20"
     ]
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "import math \n",
      "\n",
      "# Variables :\n",
      "mi = 0.5;\t\t\t#Kg\n",
      "Ti = -10.+273;\t\t\t#K\n",
      "Cpi = 2.;\t\t\t#KJ/KgK\n",
      "Cpw = 4.2;\t\t\t#KJ/KgK\n",
      "Li = 334.;\t\t\t#KJ/Kg\n",
      "mc = 5.;\t\t\t#Kg\n",
      "Tc = 80.+273;\t\t\t#K\n",
      "Cpc = 0.5;\t\t\t#KJ/KgK\n",
      "T0 = 0.+273;\t\t\t#K\n",
      "\n",
      "# Calculations and Results\n",
      "#mi*[Cpi*(T0-Ti)+Li+Cpw*(T-T0)] = mc*Cpc*(Tc-T)\n",
      "T = (mc*Cpc*Tc-mi*Cpi*(T0-Ti)-mi*Li+mi*Cpw*T0)/(mi*Cpw+mc*Cpc);\t\t\t#K\n",
      "deltaSi = mi*Cpi*math.log(T0/Ti)+Li/T0+mi*Cpw*math.log(T/T0);\t\t\t#KJ/K\n",
      "print \"Entropy chane of Ice in KJ/K : %.4f\"%deltaSi\n",
      "\n",
      "deltaSc = mc*Cpc*math.log(T/Tc);\t\t\t#KJ/K\n",
      "print \"Entropy chane of Copper in KJ/K : %.4f\"%deltaSc\n",
      "\n",
      "deltaSsurr = 0;\t\t\t#No heat transfer between system & Surrounding\n",
      "deltaSuniverse = deltaSi+deltaSc+deltaSsurr;\t\t\t#KJ/K\n",
      "print \"Entropy chane of universe in KJ/K : %.4f\"%deltaSuniverse\n"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "Entropy chane of Ice in KJ/K : 1.2989\n",
        "Entropy chane of Copper in KJ/K : -0.5971\n",
        "Entropy chane of universe in KJ/K : 0.7018\n"
       ]
      }
     ],
     "prompt_number": 1
    },
    {
     "cell_type": "heading",
     "level": 2,
     "metadata": {},
     "source": [
      "Example 4.8 Page No : 21"
     ]
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "import scipy\n",
      "from scipy.integrate import quad \n",
      "\t\t\t\n",
      "# Variables :\n",
      "m1 = 5.;\t\t\t#Kg\n",
      "T1 = 200.+273;\t\t\t#K\n",
      "Cp1 = 0.4;\t\t\t#KJ/KgK\n",
      "m2 = 100.;\t\t\t#Kg\n",
      "T2 = 30.+273;\t\t\t#K\n",
      "Cp2 = 2.1;\t\t\t#KJ/KgK\n",
      "\n",
      "# Calculations\n",
      "#m1*Cp1*(T1-T) = m2*Cp2*(T-T2)\n",
      "T = (m1*Cp1*T1+T2*m2*Cp2)/(m2*Cp2+m1*Cp1);\t\t\t#K\n",
      "\n",
      "def f8(T): \n",
      "\t return m1*Cp1/T\n",
      "\n",
      "deltaS1 =  quad(f8,T1,T)[0]\n",
      "\n",
      "def f9(T): \n",
      "\t return m2*Cp2/T\n",
      "\n",
      "deltaS2 =  quad(f9,T2,T)[0]\n",
      "deltaSsurr = 0;\t\t\t#No heat transfer neglected\n",
      "deltaSuniverse = deltaS1+deltaS2+deltaSsurr;\t\t\t#KJ/K\n",
      "\n",
      "# Results\n",
      "print \"Increase in Entropy of universe in KJ/K : %.4f\"%deltaSuniverse\n"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "Increase in Entropy of universe in KJ/K : 0.2284\n"
       ]
      }
     ],
     "prompt_number": 8
    },
    {
     "cell_type": "heading",
     "level": 2,
     "metadata": {},
     "source": [
      "Example 4.9 Page No : 22"
     ]
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "import scipy\n",
      "from scipy.integrate import quad \n",
      "\n",
      "# Variables :\n",
      "HeatTransfer = 2;\t\t\t#KJ/degreeCentigrade(it is d'Q/dT)\n",
      "T1 = 27+273;\t\t\t#K\n",
      "T2 = 127+273;\t\t\t#K\n",
      "\n",
      "# Calculations\n",
      "def f22(T): \n",
      "\t return HeatTransfer/T\n",
      "\n",
      "deltaS =  quad(f22,T1,T2)[0]\n",
      "\n",
      "# Results\n",
      "print \"Entropy change when heat is transfered to system in KJ/K : %.4f\"%deltaS\n",
      "print  \"change when end states are achieved by stirring action in KJ/K : %.4f\"%deltaS\n"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "Entropy change when heat is transfered to system in KJ/K : 0.5754\n",
        "change when end states are achieved by stirring action in KJ/K : 0.5754\n"
       ]
      }
     ],
     "prompt_number": 9
    },
    {
     "cell_type": "heading",
     "level": 2,
     "metadata": {},
     "source": [
      "Example 4.11 Page No : 23"
     ]
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "import scipy\n",
      "from scipy.integrate import quad \n",
      "\t\t\t\n",
      "# Variables :\n",
      "m1 = 2.;\t\t\t#Kg\n",
      "T1 = 80.+273;\t\t\t#K\n",
      "m2 = 3.;\t\t\t#Kg\n",
      "T2 = 30.+273;\t\t\t#K\n",
      "Cp = 4.187;\t\t\t#KJ/KgK\n",
      "\n",
      "# Calculations\n",
      "#m1*Cp1*(T1-T) = m2*Cp2*(T-T2)\n",
      "T = (m1*Cp*T1+T2*m2*Cp)/(m2*Cp+m1*Cp);\t\t\t#K\n",
      "\n",
      "def f26(T): \n",
      "\t return m1*Cp/T\n",
      "\n",
      "deltaS =  quad(f26,T1,T)[0] + 0.8029\n",
      "\n",
      "print \"Total Entropy change due to mixing process in KJ/K : %.4f\"%deltaS\n"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "Total Entropy change due to mixing process in KJ/K : 0.0592\n"
       ]
      }
     ],
     "prompt_number": 8
    },
    {
     "cell_type": "heading",
     "level": 2,
     "metadata": {},
     "source": [
      "Example 4.14 Page No : 26"
     ]
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "from scipy.integrate import quad \n",
      "\t\t\t\n",
      "# Variables :\n",
      "V1 = 4.;\t\t\t#m**3\n",
      "V2 = 4.;\t\t\t#m**3\n",
      "m = 20.;\t\t\t#Kg\n",
      "p1 = 4.*100;\t\t\t#KPa\n",
      "p2 = 8.*100;\t\t\t#KPa\n",
      "Cp = 1.005;\t\t\t#KJ/KgK\n",
      "Cv = 0.718;\t\t\t#KJ/KgK\n",
      "\n",
      "# Calculations and Results\n",
      "R = Cp-Cv;\t\t\t#KJ/KgK\n",
      "T1 = p1*V1/m/R;\t\t\t#K\n",
      "T2 = p2*V2/m/R;\t\t\t#K\n",
      "deltaU = m*Cv*(T2-T1);\t\t\t#KJ\n",
      "print \"Change in internal energy in KJ : %.2f\"%deltaU\n",
      "W = 0;\t\t\t#KJ\n",
      "print  \"no movement, Work done in KJ : \",W\n",
      "\n",
      "Q = W+deltaU;\t\t\t#KJ\n",
      "print \"Heat transfered in KJ : %.2f\"%Q\n",
      "\n",
      "def f19(T): \n",
      "\t return m*Cv/T\n",
      "\n",
      "deltaS =  quad(f19,T1,T2)[0]\n",
      "\n",
      "print \"Entropy change  in KJ/K : %.4f\"%deltaS\n"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "Change in internal energy in KJ : 4002.79\n",
        "no movement, Work done in KJ :  0\n",
        "Heat transfered in KJ : 4002.79\n",
        "Entropy change  in KJ/K : 9.9536\n"
       ]
      }
     ],
     "prompt_number": 11
    },
    {
     "cell_type": "heading",
     "level": 2,
     "metadata": {},
     "source": [
      "Example 4.15 Page No : 26"
     ]
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "import scipy\n",
      "from scipy.integrate import quad \n",
      "\t\t\t\n",
      "# Variables :\n",
      "V1 = 4.;\t\t\t#m**3\n",
      "V2 = 4.;\t\t\t#m**3\n",
      "m = 600./1000;\t\t\t#Kg\n",
      "C = 150.;\t\t\t#J/K\n",
      "T1 = 100.+273;\t\t\t#K\n",
      "T0 = 8.+273;\t\t\t#K\n",
      "Cp = C/1000;\t\t\t#KJ/K\n",
      "\n",
      "# Calculations and Results\n",
      "def f10(T): \n",
      "\t return Cp/T\n",
      "\n",
      "deltaSblock =  quad(f10,T1,T0)[0]\n",
      "\n",
      "Q = Cp*(T1-T0);\t\t\t#KJ\n",
      "deltaSlake = Q/T0;\t\t\t#KJ/K\n",
      "deltaSuniverse = deltaSblock+deltaSlake;\t\t\t#KJ/K\n",
      "print \"Part (i) Entropy change of universe in KJ/K : %.4f\"%deltaSuniverse\n",
      "\n",
      "T1 = 8.+273;\t\t\t#K\n",
      "Z = 100.;\t\t    \t#meter\n",
      "g = 9.81;\t\t\t    #gravity constant\n",
      "PE = m*g*Z/1000.;\t\t#KJ\n",
      "deltaT = PE/Cp;\t\t\t#degree centigrade\n",
      "T2 = T1+deltaT;\t\t\t#K\n",
      "\n",
      "def f11(T): \n",
      "\t return Cp/T\n",
      "\n",
      "deltaSblock = - quad(f11,T1,T2)[0]\n",
      "\n",
      "deltaSlake = PE/T0;\t\t\t#KJ/K\n",
      "deltaSuniverse = deltaSblock+deltaSlake;\t\t\t#KJ/K\n",
      "print \"Part (ii) Entropy change of universe in %f KJ/K : \"%deltaSuniverse\n"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "Part (i) Entropy change of universe in KJ/K : 0.0066\n",
        "Part (ii) Entropy change of universe in 0.000014 KJ/K : \n"
       ]
      }
     ],
     "prompt_number": 1
    },
    {
     "cell_type": "heading",
     "level": 2,
     "metadata": {},
     "source": [
      "Example 4.17 Page No : 29"
     ]
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "import math \n",
      "\n",
      "\n",
      "# Variables :\n",
      "m = 1.;\t\t\t#Kg\n",
      "p1 = 1.;\t\t\t#bar\n",
      "T1 = 290.;\t\t\t#K\n",
      "p2 = 30.;\t\t\t#bar\n",
      "T2 = 290.;\t\t\t#K\n",
      "n = 1.3;\t\t\t#consmath.tant\n",
      "R = 300.;\t\t\t#Nm/KgK\n",
      "Cv = 0.72;\t\t\t#KJ/KgK\n",
      "\n",
      "# Calculations and Results\n",
      "print (\"part (a) Isothermally\")\n",
      "V1 = R*T1/p1/10**5;\t\t\t#m**3/Kg\n",
      "V2 = p1*V1/p2;\t\t\t#m**3/Kg\n",
      "w = p1*10**5*V1*math.log(V2/V1)/1000;\t\t\t#KJ/Kg\n",
      "print \"Workdone in KJ/Kg : %.1f\"%w\n",
      "\n",
      "deltaU = m*Cv*(T2-T1);\t\t\t#KJ(as T1 = T2)\n",
      "print \"Change in internal energy in KJ : \",deltaU\n",
      "\n",
      "q = w+deltaU;\t\t\t#KJ/Kg\n",
      "print \"Heat transfer in KJ/Kg : %.1f\"%q\n",
      "\n",
      "S2subS1 = m*R/1000*math.log(V2/V1)+m*Cv*math.log(T2/T1);\t\t\t#KJ/KgK\n",
      "print \"Change in entropy in KJ/KgK : %.4f\"%S2subS1\n",
      "\n",
      "print (\"\\npart (b) Polytropically\")\n",
      "T2 = T1*(p2/p1)**((n-1)/n);\t\t\t#K\n",
      "print \"Temperature T2 in K : %.1f\"%T2\n",
      "\n",
      "V1 = R*T1/p1/10**5;\t\t\t#m**3/Kg\n",
      "V2 = (p1/p2)**(1/n)*V1;\t\t\t#m**3/Kg\n",
      "w =  m*R/1000*(T1-T2)/(n-1);\t\t\t#KJ/Kg\n",
      "print \"Workdone in KJ/Kg : %.1f\"%w\n",
      "\n",
      "deltaU = m*Cv*(T2-T1);\t\t\t#KJ(as T1 = T2)\n",
      "q = w+deltaU;\t\t\t#KJ/Kg\n",
      "print \"Heat transfer in KJ/Kg : %.1f\"%q\n",
      "\n",
      "S2subS1 = m*R/1000*math.log(V2/V1)+m*Cv*math.log(T2/T1);\t\t\t#KJ/KgK\n",
      "print \"Change in entropy in KJ/KgK : %.4f\"%S2subS1\n"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "part (a) Isothermally\n",
        "Workdone in KJ/Kg : -295.9\n",
        "Change in internal energy in KJ :  0.0\n",
        "Heat transfer in KJ/Kg : -295.9\n",
        "Change in entropy in KJ/KgK : -1.0204\n",
        "\n",
        "part (b) Polytropically\n",
        "Temperature T2 in K : 635.7\n",
        "Workdone in KJ/Kg : -345.7\n",
        "Heat transfer in KJ/Kg : -96.8\n",
        "Change in entropy in KJ/KgK : -0.2198\n"
       ]
      }
     ],
     "prompt_number": 2
    },
    {
     "cell_type": "heading",
     "level": 2,
     "metadata": {},
     "source": [
      "Example 4.18 Page No : 30"
     ]
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "import math \n",
      "\t\t\t\n",
      "# Variables :\n",
      "P1 = 480.;\t\t\t#kPa\n",
      "T1 = 190.+273;\t\t\t#K\n",
      "T3 = 190.+273;\t\t\t#K\n",
      "P2 = 94.;\t\t\t#kPa\n",
      "P3 = 150.;\t\t\t#kPa\n",
      "T2 = T3*P2/P3;\t\t\t#K\n",
      "R = 0.29;\t\t\t#KJ/KgK\n",
      "m = 1.;\t\t\t#Kg\n",
      "Cp = 1.011;\t\t\t#KJ/KgK\n",
      "\n",
      "#T2/T1 = (P2/P1)**((Gamma-1)/Gamma)\n",
      "#((Gamma-1)/Gamma) = math.log(T2/T1)/math.log(P2/P1);\t\t\t#\n",
      "Gamma = 1.402;\t\t\t#by trial method\n",
      "print \"Index of adiabatic expansion : %.2f\"%Gamma\n",
      "\n",
      "Cv = R/(Gamma-1);\t\t\t#KJ/KgK\n",
      "W1_2 = m*R*(T1-T2)/(Gamma-1);\t\t\t#KJ/Kg\n",
      "print \"Work done, W1-2 per Kg of air in KJ/Kg : %.2f\"%W1_2\n",
      "\n",
      "W2_3 = 0;\t\t\t#Consmath.tant volume process\n",
      "print \"Work done, W2-3 per Kg of air in KJ/Kg : %.0f\"%W2_3\n",
      "\n",
      "W3_1 = m*R*T2*math.log(P3/P1);\t\t\t#KJ/Kg\n",
      "print \"Work done, W1-2 per Kg of air in KJ/Kg : %.2f\"%W3_1\n",
      "\n",
      "W = W1_2+W2_3+W3_1;\t\t\t#KJ/Kg\n",
      "print \"Total Work done in KJ/Kg : %.2f\"%W\n",
      "\n",
      "S2subS1 = 0;\t\t\t#adiabatic process\n",
      "S3subS2 = m*R*math.log(P2/P3)+m*Cp*math.log(T3/T2);\t\t\t#KJ/KgK\n",
      "print \"Change in specific entropy, S1-2 in KJ/KgK ;  %.3f\"%S3subS2\n",
      "\n",
      "S1subS3 = -S2subS1-S3subS2;\t\t\t#KJ/KgK\n",
      "print \"Change in specific entropy, S3-1 in KJ/KgK ;  %.3f\"%S1subS3\n"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "Index of adiabatic expansion : 1.40\n",
        "Work done, W1-2 per Kg of air in KJ/Kg : 124.70\n",
        "Work done, W2-3 per Kg of air in KJ/Kg : 0\n",
        "Work done, W1-2 per Kg of air in KJ/Kg : -97.87\n",
        "Total Work done in KJ/Kg : 26.82\n",
        "Change in specific entropy, S1-2 in KJ/KgK ;  0.337\n",
        "Change in specific entropy, S3-1 in KJ/KgK ;  -0.337\n"
       ]
      }
     ],
     "prompt_number": 16
    },
    {
     "cell_type": "heading",
     "level": 2,
     "metadata": {},
     "source": [
      "Example 4.21 Page No : 33"
     ]
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "import math \n",
      "\t\t\t\n",
      "# Variables :\n",
      "p1 = 5.;\t\t\t#bar\n",
      "T1 = 30.+273;\t\t\t#K\n",
      "p2 = 4.;\t\t\t#bar\n",
      "m = 1.; \t\t\t#Kg\n",
      "R = 0.287;\t\t\t#KJ/KgK\n",
      "\n",
      "# Calculations\n",
      "#deltaS = m*R*math.log(p1/p2)+m*Cp*math.log(T2/T1);\t\t\t#KJ/kgK\n",
      "deltaS = m*R*math.log(p1/p2);\t\t\t#KJ/kgK(T2/T1 leads to 2nd term zero)\n",
      "\n",
      "# Results\n",
      "print \"Entropy Change in KJ/KgK :  %.5f\"%deltaS\n"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "Entropy Change in KJ/KgK :  0.06404\n"
       ]
      }
     ],
     "prompt_number": 17
    },
    {
     "cell_type": "heading",
     "level": 2,
     "metadata": {},
     "source": [
      "Example 4.22 Page No : 34"
     ]
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "import scipy\n",
      "from scipy.integrate import quad \n",
      "\t\t\t\n",
      "# Variables :\n",
      "Cpg = 1.05;\t\t\t#KJ/KgK\n",
      "t1 = 400.;\t\t\t#degree centigrade\n",
      "t2 = 360.;\t\t\t#degree centigrade\n",
      "T = 30.+273;\t\t\t#K\n",
      "\n",
      "# Calculations\n",
      "Q = Cpg*(t1-t2);\t\t\t#KJ/Kg\n",
      "deltaSsurr = Q/T;\t\t\t#KJ/KgK\n",
      "\n",
      "def f25(T): \n",
      "\t return Cpg/T\n",
      "\n",
      "deltaSsystem =  quad(f25,t1+273,t2+273)[0]\n",
      "deltaSuniverse = deltaSsystem+deltaSsurr;\t\t\t#KJ/KgK\n",
      "\n",
      "# Results\n",
      "print \"Change in entropy of the universe in KJ/KgK :  %.4f\"%deltaSuniverse\n"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "Change in entropy of the universe in KJ/KgK :  0.0743\n"
       ]
      }
     ],
     "prompt_number": 18
    }
   ],
   "metadata": {}
  }
 ]
}