{ "metadata": { "name": "" }, "nbformat": 3, "nbformat_minor": 0, "worksheets": [ { "cells": [ { "cell_type": "heading", "level": 1, "metadata": {}, "source": [ "Chapter 2 : Basic Concepts Of Thermodynamicsm" ] }, { "cell_type": "heading", "level": 3, "metadata": {}, "source": [ "Example 2.1 Page no : 41" ] }, { "cell_type": "code", "collapsed": false, "input": [ "# Convert the following readings of pressure to kPa assuming that barometer reads 760 mm of Hg.\n", "\n", "# Variables\n", "rho_Hg = 13596.; \t\t\t#kg/m**3\n", "g = 9.806; \t\t\t#m/s**2\n", "h = 0.76; \t\t\t#m\n", "\n", "# Calculations and Results\n", "P = rho_Hg*g*h/1000; \t\t\t#kPa\n", "\n", "\n", "h1 = 0.80; \t\t\t#m\n", "P1 = h1/h*P;\n", "print \"(i) Pressure of 80 cm of Hg %.3f kPa\"%P1\n", "\n", "\n", "print (\"(ii) 30 cm Hg vacuum\")\n", "H2 = 0.30; \t\t\t#cm Hg vacuum\n", "h2 = h-H2; \t\t\t#cm of Hg absolute\n", "\n", "P2 = h2/h*P;\n", "print \"Pressure due to 46 cm of Hg %.3f kPa\"%P2\n", "\n", "rho_H2O = 1000; \t\t\t#kg/m**3\n", "h3 = 1.35; \t\t\t#m\n", "P3 = rho_H2O*g*h3/1000;\n", "print \"(iii) Pressure due to 1.35 m H2O gauge %.3f kPa\"%(P3)\n", "\n", "\n", "P4 = 4.2*10**2;\n", "print \"(iv) 4.2 bar %.3f kPa\"%(P4),\n", "\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "(i) Pressure of 80 cm of Hg 106.658 kPa\n", "(ii) 30 cm Hg vacuum\n", "Pressure due to 46 cm of Hg 61.328 kPa\n", "(iii) Pressure due to 1.35 m H2O gauge 13.238 kPa\n", "(iv) 4.2 bar 420.000 kPa\n" ] } ], "prompt_number": 3 }, { "cell_type": "heading", "level": 3, "metadata": {}, "source": [ "Example 2.2 page no : 42" ] }, { "cell_type": "code", "collapsed": false, "input": [ "# Find the pressure on the piston.\n", "\n", "import math \n", "\n", "# Variables\n", "d = 0.1; \t\t\t#m\n", "F = 1000.; \t\t\t#N\n", "\n", "# Calculations\n", "A = math.pi/4*d**2; \t\t\t#m**2\n", "P = F/A/10**3;\n", "\n", "# Results\n", "print \"Pressure on the piston = %.3f kN/m**2\"%(P),\n", "\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Pressure on the piston = 127.324 kN/m**2\n" ] } ], "prompt_number": 4 }, { "cell_type": "heading", "level": 3, "metadata": {}, "source": [ "Example 2.3 page no : 42" ] }, { "cell_type": "code", "collapsed": false, "input": [ "#Find the gauge pressure \n", "\n", "# Variables\n", "SG = 0.9;\n", "h = 1.2; \t\t\t#m\n", "g = 9.81; \t\t\t#m/s**2\n", "rho_w = 1000.; \t\t\t#kg/m**3\n", "\n", "# Calculations\n", "rho = SG*rho_w; \t\t\t#kg/m**3\n", "P = rho*g*h/10**3;\n", "\n", "# Results\n", "print \"Gauge pressure P = %.3f kN/m**2\"%(P)\n", "\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Gauge pressure P = 10.595 kN/m**2\n" ] } ], "prompt_number": 5 }, { "cell_type": "heading", "level": 3, "metadata": {}, "source": [ "Example 2.4 page no : 43" ] }, { "cell_type": "code", "collapsed": false, "input": [ "#Find the absolute pressure in the condenser in Pa. \n", "\n", "# Variables\n", "Vacuum_recorded = 740.; \t\t\t#mm of Hg\n", "Barometric_reading = 760.; \t\t\t#mm of Hg\n", "\n", "# Calculations\n", "Absolute_pressure = (Barometric_reading-Vacuum_recorded)*133.4;\n", "\n", "# Results\n", "print \"Absolute pressure in the condenser = %.3f Pa\"%(Absolute_pressure),\n", "\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Absolute pressure in the condenser = 2668.000 Pa\n" ] } ], "prompt_number": 6 }, { "cell_type": "heading", "level": 3, "metadata": {}, "source": [ "Example 2.5 page no : 43" ] }, { "cell_type": "code", "collapsed": false, "input": [ "'''\n", "Determine :\n", "(i) The absolute pressure of the gas in the vessel in bar.\n", "(ii) Specific volume and density of the gas.\n", "'''\n", "\n", "import math \n", "\n", "# Variables\n", "d = 0.5; \t\t\t#m\n", "h = 0.75; \t\t\t#m\n", "m = 4.; \t\t\t#kg\n", "Manometer_reading = 620.; \t\t\t#mm of Hg above atmosphere\n", "Barometer_reading = 760.; \t\t\t#mm of Hg\n", "V = math.pi/4*d**2*h; \t\t\t#m**3\n", "print (\"(i) Total pressure in the vessel\")\n", "\n", "# Calculations and Results\n", "P = (Barometer_reading+Manometer_reading)*133.4/10**5; \t\t\t#bar\n", "print \"P = %.3f bar\"%(P)\n", "\n", "print (\"(ii) Specific volume and density\")\n", "SV = V/m; \n", "print \"Specific volume = %.3f m**3/kg\"%(SV)\n", "\n", "D = m/V;\n", "print \"Density = %.3f kg/m**3\"%(D),\n", "\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "(i) Total pressure in the vessel\n", "P = 1.841 bar\n", "(ii) Specific volume and density\n", "Specific volume = 0.037 m**3/kg\n", "Density = 27.162 kg/m**3\n" ] } ], "prompt_number": 8 }, { "cell_type": "heading", "level": 3, "metadata": {}, "source": [ "Example 2.6 page no : 43" ] }, { "cell_type": "code", "collapsed": false, "input": [ "'''\n", "Calculate the gas pressure.\n", "'''\n", "\n", "\n", "# Variables\n", "h0 = .761; \t\t\t#m\n", "h = .55; \t\t\t#m\n", "g = 9.79; \t\t\t#m/s**2\n", "rho = 13640.; \t\t\t#kg/m**3\n", "\n", "# Calculations\n", "P = rho*g*(h0+h); \t\t\t#N/m**2\n", "\n", "# Results\n", "print \"Gas pressure = %.3f bar\"%(P/10**5),\n", "\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Gas pressure = 1.751 bar\n" ] } ], "prompt_number": 9 }, { "cell_type": "heading", "level": 3, "metadata": {}, "source": [ "Example 2.7 page no : 44" ] }, { "cell_type": "code", "collapsed": false, "input": [ "'''\n", "Find the absolute pressure of steam.\n", "'''\n", "\n", "# Variables\n", "h_H2O = 34.; \t\t\t#mm of Hg\n", "g = 9.81; \t\t\t#m/s**2\n", "rho = 13600.; \t\t\t#kg/m**3\n", "P_Hg = 97.5; \t\t\t#mm of Hg\n", "P_atm = 760.; \t\t\t#mm of Hg\n", "\n", "# Calculations\n", "P_H2O = h_H2O/13.6; \t\t\t#mm of Hg\n", "Pabs = rho*g*(P_Hg+P_atm-P_H2O)/10**8; \t\t\t#bar\n", "\n", "# Results\n", "print \"absolute pressure = %.3f bar\"%(Pabs)\n", "\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "absolute pressure = 1.141 bar\n" ] } ], "prompt_number": 10 }, { "cell_type": "heading", "level": 3, "metadata": {}, "source": [ "Example 2.8 page no : 44" ] }, { "cell_type": "code", "collapsed": false, "input": [ "'''\n", "Find the absolute pressure of the gas \n", "'''\n", "\n", "# Variables\n", "SG = 0.8;\n", "rho_H2O = 1000.; \t\t\t#kg/m**3\n", "g = 9.81; \t\t\t#ms**2\n", "h = 0.17; \t\t\t#m\n", "Patm = 1.01325; \t\t\t#bar\n", "\n", "# Calculations\n", "rho = SG*rho_H2O; \t\t\t#kg/m**3\n", "P_liq = rho*g*h/10**5; \t\t\t#bar\n", "P_gas = Patm - P_liq;\n", "\n", "# Results\n", "print \"gas pressure = %.3f bar\"%(P_gas),\n", "\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "gas pressure = 1.000 bar\n" ] } ], "prompt_number": 11 }, { "cell_type": "heading", "level": 3, "metadata": {}, "source": [ "Example 2.9 page no : 45" ] }, { "cell_type": "code", "collapsed": false, "input": [ "'''\n", "Estimate the mass of a piston that can be supported by a gas entrapped\n", "under the piston '''\n", "\n", "import math \n", "\n", "# Variables\n", "d = 0.2; \t\t\t#m\n", "g = 9.81; \t\t\t#m/s**2\n", "h = 0.117; \t\t\t#m\n", "rho = 13600.; \t\t\t#kg/m**3\n", "\n", "# Calculations\n", "p = rho*g*h;\n", "m = (p*math.pi/4*d**2)/g;\n", "\n", "# Results\n", "print \"mass = %.3f kg\"%(m),\n", "\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "mass = 49.989 kg\n" ] } ], "prompt_number": 12 }, { "cell_type": "heading", "level": 3, "metadata": {}, "source": [ "Example 2.10 page no : 49" ] }, { "cell_type": "code", "collapsed": false, "input": [ "'''\n", "calculate the kinetic energy of an artificial satellite revolves round the earth \n", "'''\n", "\n", "# Variables\n", "v = 800.; \t\t\t#m/s\n", "g = 9.; \t\t\t#m/s**2\n", "F = 3600.; \t\t\t#N\n", "\n", "# Calculations\n", "m = F/g;\n", "KE = 1./2*m*v**2./10**6;\n", "\n", "# Results\n", "print \"Kinetic Energy = %.3f MJ\"%(KE),\n", "\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Kinetic Energy = 128.000 MJ\n" ] } ], "prompt_number": 13 }, { "cell_type": "heading", "level": 3, "metadata": {}, "source": [ "Example 2.11 page no : 49" ] }, { "cell_type": "code", "collapsed": false, "input": [ "'''\n", "find :\n", "(i) Heat transferred ;\n", "(ii) Mean specific heat of the gas.\n", "'''\n", "\n", "import math \n", "from scipy.integrate import quad \n", "\n", "# Variables\n", "m = 6.; \t\t\t#kg\n", "T1 = 25.; \t\t\t#0C\n", "T2 = 125.; \t\t\t#0C\n", "\n", "print (\"(i) Heat transferred\")\n", "\n", "# Calculations and Results\n", "def f18(T): \n", "\t return m*(0.4+0.004*T)\n", "\n", "Q = quad(f18,T1,T2)[0]\n", "\n", "print \"heat tranferred = %.3f kJ\"%(Q)\n", "\n", "print (\"(ii) Mean specific heat of the gas\")\n", "c_n = Q/m/(T2-T1);\n", "print \"Mean specific heat = %.3f kJ/kg.0C\"%(c_n),\n", "\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "(i) Heat transferred\n", "heat tranferred = 420.000 kJ\n", "(ii) Mean specific heat of the gas\n", "Mean specific heat = 0.700 kJ/kg.0C\n" ] } ], "prompt_number": 15 }, { "cell_type": "heading", "level": 3, "metadata": {}, "source": [ "Example 2.12 page no : 50" ] }, { "cell_type": "code", "collapsed": false, "input": [ "'''\n", "what will be the temperature corresponding to the thermometric property of 3.5 on\n", "Celsius scale.\n", "'''\n", "\n", "import math \n", "from numpy import *\n", "# Variables\n", "Ice_point = 0.;\n", "Steam_point = 100.;\n", "\n", "# Calculations\n", "P = [[math.log(1.5),1],[math.log(7.5),1]];\n", "Q = [0,100];\n", "X = linalg.inv(P)*Q;\n", "\n", "a = X[0,1];\n", "b = X[1,1];\n", "p = 3.5;\n", "t = a*math.log(p)+b;\n", "\n", "# Results\n", "print (\"The value of temperature is given by %.3f\")%(t),(\"\u00b0C\")\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "The value of temperature is given by 52.646 \u00b0C\n" ] } ], "prompt_number": 7 }, { "cell_type": "heading", "level": 3, "metadata": {}, "source": [ "Example 2.13 page no : 50" ] }, { "cell_type": "code", "collapsed": false, "input": [ "'''\n", "What will be the reading on the thermometer where the gas thermometer reads 70\u00b0C ?\n", "'''\n", "\n", "def func(t): \n", "\t return 0.20*t-5*10**(-4)*t**2\n", "# Variables # Calculations\n", "t1 = 0; \t\t\t#0C\n", "e1 = func(t1);\n", "t2 = 100; \t\t\t#0C\n", "e2 = func(t2);\n", "t3 = 70; \t\t\t#0C\n", "e3 = func(t3);\n", "t = e3*(t2-t1)/e2-e1;\n", "\n", "# Results\n", "print \"thermocouple will read\",t,\"\u00b0C\"\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "thermocouple will read 77.0 \u00b0C\n" ] } ], "prompt_number": 18 }, { "cell_type": "heading", "level": 3, "metadata": {}, "source": [ "Example 2.15 page no : 51" ] }, { "cell_type": "code", "collapsed": false, "input": [ "'''\n", "What is the amount of work done upon the atmosphere by the balloon ? \n", "'''\n", "\n", "# Variables\n", "p = 101.325; \t\t#kPa\n", "V2 = 0.6; \t\t\t#m**3\n", "V1 = 0; \t\t\t#m**3\n", "\n", "# Calculations\n", "W = p*(V2-V1);\n", "\n", "# Results\n", "print (\"work done by atmosphere = \"),(-W),\"kJ\"\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "work done by atmosphere = -60.795 kJ\n" ] } ], "prompt_number": 19 }, { "cell_type": "heading", "level": 3, "metadata": {}, "source": [ "Example 2.16 page no : 52" ] }, { "cell_type": "code", "collapsed": false, "input": [ "'''\n", "Determine the work done by the air which enters into an evacuated vessel\n", "from atmosphere when the valve is opened'''\n", "\n", "from scipy import integrate\n", "\n", "# Variables\n", "#p = 1.013*10**5; \t#N/m**2\n", "p = lambda x: 1.013*10**5\n", "V1 = 1.5; \t\t\t#m**3\n", "V2 = 0; \t\t\t#m**3\n", "\n", "# Calculations\n", "integ, err = integrate.quad(p,V1,V2)\n", "\n", "# Results\n", "print (\"W = \"),(integ/10**3),\"kJ\"\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "W = -151.95 kJ\n" ] } ], "prompt_number": 4 }, { "cell_type": "heading", "level": 3, "metadata": {}, "source": [ "Example 2.17 page no : 53" ] }, { "cell_type": "code", "collapsed": false, "input": [ "'''\n", "A piston and cylinder machine containing a fluid system has a stirring\n", "device as shown in Fig. 2.36. Find the net work transfer for the system.\n", "'''\n", "\n", "import math \n", "\n", "# Variables\n", "T = 1.25; \t\t\t#N.m\n", "N = 9500.;\n", "p = 101.3; \t\t\t#kPa\n", "d = 0.65; \t\t\t#m\n", "L = 0.6; \t\t\t#m\n", "\n", "# Calculations\n", "W1 = 2*math.pi*N*T/1000; \t#kJ\n", "A = math.pi/4*d**2; #m**2\n", "W2 = p*A*L; \t\t#kJ\n", "Wnet = (-W1)+W2;\n", "\n", "# Results\n", "print \"The net work transfer for the system = %.3f\"%(Wnet),\"kJ\"\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "The net work transfer for the system = -54.444 kJ\n" ] } ], "prompt_number": 21 }, { "cell_type": "heading", "level": 3, "metadata": {}, "source": [ "Example 2.18 page no : 53" ] }, { "cell_type": "code", "collapsed": false, "input": [ "'''\n", "Find the net work done during the process.\n", "'''\n", "\n", "# Variables\n", "A = 45.*10**(-4); \t #m**2\n", "P = 0.9*10**5; \t\t #N/m**2\n", "Patm = 1.013*10**5; #N/m**2\n", "L = 0.05; \t\t\t #m\n", "\n", "# Calculations\n", "dV = 300.*10**(-6); \t\t\t#m**3\n", "W = P*A*L-Patm*dV;\n", "\n", "# Results\n", "print (\"net work done = \"),(W),\"J\"\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "net work done = -10.14 J\n" ] } ], "prompt_number": 22 }, { "cell_type": "heading", "level": 3, "metadata": {}, "source": [ "Example 2.19 page no : 54" ] }, { "cell_type": "code", "collapsed": false, "input": [ "'''\n", "Calculate the work done when the pressure increases from 1.5 bar to 7.5 bar.\n", "'''\n", "\n", "import math \n", "from scipy.integrate import quad \n", "\n", "# Variables\n", "p1 = 1.5; \t\t\t#bar\n", "p2 = 7.5; \t\t\t#bar\n", "V1 = 3/p1;\n", "V2 = 3/p2;\n", "\n", "# Calculations\n", "def f19( V): \n", "\t return 3./V*10**2\n", "\n", "W = quad(f19, V1, V2)[0]\n", "\n", "# Results\n", "print \"Work done = %.3f\"%(W),\"kJ\"\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Work done = -482.831 kJ\n" ] } ], "prompt_number": 23 }, { "cell_type": "heading", "level": 3, "metadata": {}, "source": [ "Example 2.20 page no : 55" ] }, { "cell_type": "code", "collapsed": false, "input": [ "import math\n", "\n", "'''\n", "To a closed system 150 kJ of work is supplied, determine the final volume and pressure of the system.\n", "'''\n", "\n", "# Variables\n", "W = 150; \t\t\t#kJ\n", "V1 = 0.6; \t\t\t#m**3\n", "\n", "# Calculations and Results\n", "V2 = (8-math.sqrt(64-4*2*2.58))/4; \t\t\t#m**3\n", "print (\"Final volume = %.3f\")%V2,\"m**3\"\n", "\n", "p2 = 8-4*V2;\n", "print \"Final pressure = %.2f\"%p2,\"bar\"\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Final volume = 0.354 m**3\n", "Final pressure = 6.58 bar\n" ] } ], "prompt_number": 13 }, { "cell_type": "heading", "level": 3, "metadata": {}, "source": [ "Example 2.21 page no : 56" ] }, { "cell_type": "code", "collapsed": false, "input": [ "'''\n", "Calculate the work done by the fluid on the piston.\n", "'''\n", "\n", "import math \n", "from scipy.integrate import quad \n", "\n", "# Variables\n", "p1 = 3.*10**5; \t\t\t#Pa\n", "v1 = 0.18; \t\t\t#m**3/kg\n", "p2 = 0.6*10**5; \t\t\t#Pa\n", "\n", "# Calculations\n", "C = p1*v1**2;\n", "v2 = math.sqrt(C/p2);\n", "\n", "def f17( v): \n", " return C/v**2\n", "\n", "W = quad(f17, v1,v2)[0]\n", "\n", "# Results\n", "print (\"Work done = %d\")%(W),(\"Nm/kg\")\n", "\n", "# Note : output would be differ as rounding error is there. v2 has rounding off error." ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Work done = 29850 Nm/kg\n" ] } ], "prompt_number": 20 }, { "cell_type": "heading", "level": 3, "metadata": {}, "source": [ "Example 2.22 page no : 57" ] }, { "cell_type": "code", "collapsed": false, "input": [ "'''\n", "Calculate the net work done by the fluid, for an initial volume of 0.05 m 3 .\n", "'''\n", "\n", "import math \n", "from scipy.integrate import quad \n", "\n", "# Variables\n", "m = 1.; \t\t\t#kg\n", "p1 = 20.*10**5; \t#Pa\n", "V1 = 0.05; \t\t\t#m**3\n", "\n", "# Calculations\n", "V2 = 2*V1;\n", "p2 = p1*(V1/V2)**2;\n", "C = p1*V1**2;\n", "V3 = V1;\n", "\n", "def f20( V): \n", "\t return C/V**2\n", "\n", "W_12 = quad(f20, V1,V2)[0]\n", "W_23 = p2*(V2-V3);\n", "W_net = W_12-W_23;\n", "\n", "# Results\n", "print (\"Net work done = \"),(W_net),(\"Nm\")\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Net work done = 25000.0 Nm\n" ] } ], "prompt_number": 26 } ], "metadata": {} } ] }