{ "metadata": { "name": "", "signature": "sha256:83b04c725ceaf9254a1b319f62cfdfa8f3ba518f51286a3d08dbbb299f685e47" }, "nbformat": 3, "nbformat_minor": 0, "worksheets": [ { "cells": [ { "cell_type": "heading", "level": 1, "metadata": {}, "source": [ "Chapter 7 : Thermodynamic Relations" ] }, { "cell_type": "heading", "level": 3, "metadata": {}, "source": [ "Example 7.17 Page no : 370" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "\n", "# Variables\n", "B = 5.*10**(-5); \t\t\t# /K\n", "K = 8.6*10**(-12); \t\t\t# m**2/N\n", "v = 0.114*10**(-3); \t\t\t#m**3/kg\n", "p2 = 800.*10**5; \t\t\t#Pa\n", "p1 = 20.*10**5; \t\t\t#Pa\n", "T = 288.; \t\t\t#K\n", "\n", "# Calculations and Results\n", "W = -v*K/2*(p2**2-p1**2);\n", "print (\"(i) Work done on the copper = %.3f\")%(W),(\"J/kg\")\n", "\n", "ds = -v*B*(p2-p1);\n", "print (\"(ii) Change in entropy = %.3f\")% (ds), (\"J/kg K\")\n", "\n", "Q = T*ds;\n", "print (\"(iii) The heat transfer = %.3f\")%(Q), (\"J/kg\")\n", "\n", "du = Q-W;\n", "print (\"(iv) Change in internal energy = %.3f\")%(du),(\"J/kg\")\n", "\n", "R = B**2*T*v/K;\n", "print (\"(v) cp \u2013 cv = %.3f\")%(R),(\"J/kg K\")\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "(i) Work done on the copper = -3.135 J/kg\n", "(ii) Change in entropy = -0.445 J/kg K\n", "(iii) The heat transfer = -128.045 J/kg\n", "(iv) Change in internal energy = -124.909 J/kg\n", "(v) cp \u2013 cv = 9.544 J/kg K\n" ] } ], "prompt_number": 1 }, { "cell_type": "heading", "level": 3, "metadata": {}, "source": [ "Example 7.18 Page no : 371" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "\n", "# Variables\n", "vg = 0.1274; \t\t\t#m**3/kg\n", "vf = 0.001157; \t\t\t#m**3/kg\n", "# dp/dT = 32; \t\t\t#kPa/K\n", "T3 = 473; \t\t\t#K\n", "\n", "# Calculations\n", "h_fg = 32*10**3*T3*(vg-vf)/10**3;\n", "\n", "# Results\n", "print (\" enthalpy of vapourisation = %.3f\")%(h_fg),(\"kJ/kg\")\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ " enthalpy of vapourisation = 1910.814 kJ/kg\n" ] } ], "prompt_number": 1 }, { "cell_type": "heading", "level": 3, "metadata": {}, "source": [ "Example 7.19 Page no : 372" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "\n", "import math\n", "\n", "# Variables\n", "h_fg = 334.; \t\t\t#kJ/kg\n", "v_liq = 1.; \t\t\t#m**3/kg\n", "v_ice = 1.01; \t\t\t#m**3/kg\n", "T1 = 273.; \t\t\t#K\n", "T2 = 263.; \t\t\t#K\n", "p1 = 1.013*10**5; \t\t\t#Pa\n", "\n", "# Calculations\n", "p2 = (p1+h_fg*10**3/(v_ice-v_liq)*math.log(T1/T2))/10**5;\n", "\n", "# Results\n", "print (\"pressure = %.3f\")%(p2),(\"bar\")\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "pressure = 13.477 bar\n" ] } ], "prompt_number": 2 }, { "cell_type": "heading", "level": 3, "metadata": {}, "source": [ "Example 7.20 Page no : 372" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "\n", "# Variables\n", "h_fg = 294.54; \t\t\t#kJ/kg\n", "p = 0.1; \t\t\t#bar\n", "T = 523; \t\t\t#K\n", "\n", "# Calculations\n", "vg = h_fg*10**3/T/(2.302*3276.6*p*10**5/T**2 - 0.652*p*10**5/T);\n", "\n", "# Results\n", "print (\"specific volume = %.3f\")%(vg),(\"m**3/kg\")\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "specific volume = 2.139 m**3/kg\n" ] } ], "prompt_number": 3 } ], "metadata": {} } ] }