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diff --git a/Internal_Combustion_Engines_by_H._B._Keswani/ch26.ipynb b/Internal_Combustion_Engines_by_H._B._Keswani/ch26.ipynb new file mode 100755 index 00000000..7221a0bb --- /dev/null +++ b/Internal_Combustion_Engines_by_H._B._Keswani/ch26.ipynb @@ -0,0 +1,296 @@ +{ + "metadata": { + "name": "", + "signature": "sha256:7b8d681b65eb5e5f473fb64f021431b36e4fa7b13f8de28bbc19ff84b5a592cb" + }, + "nbformat": 3, + "nbformat_minor": 0, + "worksheets": [ + { + "cells": [ + { + "cell_type": "heading", + "level": 1, + "metadata": {}, + "source": [ + "Chapter 26 : Jet Propulsion" + ] + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 26.1 Page no : 447" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "import math \n", + "\t\t\t\t\t\n", + "#Input data\n", + "Ve = 2700.\t\t\t\t\t#Jet exit velocity in m/s\n", + "Vf = 1350\t\t\t\t\t#Forward flight velocity in m/s\n", + "m = 78.6\t\t\t\t\t#Propellant consumption in kg/s\n", + "\n", + "\t\t\t\t\t\n", + "#Calculations\n", + "T = ((m/9.81)*(Ve-Vf))\t\t\t\t\t#Thrust in kg\n", + "TH = ((T*Vf)/75)/10**5\t\t\t\t\t#Thrust horse power in HP*10**5\n", + "pn = (2/(1+(Ve/Vf)))*100\t\t\t\t\t#Propulsive efficiency in percent\n", + "\n", + "\t\t\t\t\t\n", + "#Output\n", + "print 'i) Thrust is %3.0f kg \\\n", + "\\nii) Thrust horse power is %3.3f*10**5 H.P \\\n", + "\\niii) Propulsive efficiency is %3.1f percent'%(T,TH,pn)\n" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "i) Thrust is 10817 kg \n", + "ii) Thrust horse power is 1.947*10**5 H.P \n", + "iii) Propulsive efficiency is 66.7 percent\n" + ] + } + ], + "prompt_number": 1 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 26.2 Page no : 451" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "import math \n", + "\t\t\t\t\t\n", + "#Input data\n", + "CV = 10000\t\t\t\t\t#Calorific value in kcal/kg\n", + "F = 1.4\t\t\t\t\t#Fuel consumption in kg per hour per kg of thrust\n", + "T = 900\t\t\t\t\t#Thrust in kg\n", + "Va = 425\t\t\t\t\t#Aircraft velocity in m/s\n", + "w = 19.5\t\t\t\t\t#Weight of air in kg/sec\n", + "\n", + "\t\t\t\t\t\n", + "#Calculations\n", + "af = (w/((F*T)/3600))\t\t\t\t\t#Air fuel ratio\n", + "nv = ((T*Va*3600)/(427*F*T*CV))*100\t\t\t\t\t#Overall efficiency in percent\n", + "\n", + "\t\t\t\t\t\n", + "#Output\n", + "print 'Air fuel ratio is %3.1f \\\n", + "\\nOverall efficiency is %3.1f percent'%(af,nv)\n" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "Air fuel ratio is 55.7 \n", + "Overall efficiency is 25.6 percent\n" + ] + } + ], + "prompt_number": 2 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 26.3 Page no : 451" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "import math \n", + "\t\t\t\t\t\n", + "#Input data\n", + "a = 11500.\t\t\t\t\t#Altitude in m\n", + "n = 123.\t\t\t\t\t#Number of passengers\n", + "c = 3.\t\t\t\t\t#Cargo in tonnes\n", + "Va = 650.\t\t\t\t\t#Velocity of air craft in km/hour\n", + "d = 640.\t\t\t\t\t#Drag in kg\n", + "pe = 50.\t\t\t\t\t#Propulsion efficiency in percent\n", + "oe = 18.\t\t\t\t\t#Overall efficiency in percent\n", + "CV = 10000.\t\t\t\t\t#Calorific value in kcal/kg\n", + "da = 0.0172\t\t\t\t\t#Density of air at 11500 m in kg/cm**2\n", + "\n", + "\t\t\t\t\t\n", + "#Calculations\n", + "Vp = ((Va*1000)/3600)\t\t\t\t\t#Velocity of aeroplane in m/s\n", + "Vr = ((2/(pe/100))-1)*Vp\t\t\t\t\t#Velocity of working medium in m/s\n", + "nhp = ((d*Vp)/(75*(pe/100)))\t\t\t\t\t#Net horse power in H.P\n", + "wf = ((nhp*75*3600)/((oe/100)*427*CV))\t\t\t\t\t#Mass flow rate in kg/hr\n", + "thp = ((Va*Vp)/75)\t\t\t\t\t#Thrust horse power in H.P\n", + "F = (wf/thp)\t\t\t\t\t#Fuel consumption per thrust H.P hour in kg\n", + "W = ((Va*9.81)/Vr)\t\t\t\t\t#Air flow in kg/sec\n", + "va = (W/da)\t\t\t\t\t#Volume of air in cu.m/sec\n", + "aa = (va/(3*Vr))\t\t\t\t\t#Area of jet in m**2\n", + "d = math.sqrt((4*aa)/3.14)*100\t\t\t\t\t#Diameter of jet in cm\n", + "af = ((W*3600)/wf)\t\t\t\t\t#Air fuel ratio\n", + "\n", + "\t\t\t\t\t\n", + "#Output\n", + "print 'a) Absolute velocity of the jet is %3.1f m/sec \\\n", + "\\nb) Net horse power of the gas plant is %3.0f H.P \\\n", + "\\nc) Fuel consumption per thrust H.P hour is %3.3f kg \\\n", + "\\nd) Diameter of the jet is %3.1f cm \\\n", + "\\ne) Air-fuel ratio of the engine is %3.1f'%(Vr,nhp,F,d,af)\n", + "\n" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "a) Absolute velocity of the jet is 541.7 m/sec \n", + "b) Net horse power of the gas plant is 3081 H.P \n", + "c) Fuel consumption per thrust H.P hour is 0.692 kg \n", + "d) Diameter of the jet is 73.2 cm \n", + "e) Air-fuel ratio of the engine is 39.1\n" + ] + } + ], + "prompt_number": 4 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 26.4 Page no : 451" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "import math \n", + "\t\t\t\t\t\n", + "#Input data\n", + "p1 = 7.\t\t\t\t\t#Pressure of gas before expansion in kg/cm**2\n", + "p2 = 5.\t\t\t\t\t#Pressure of gas after expansion in kg/cm**2\n", + "T1 = 250.+273\t\t\t\t\t#Temperature of gas before expansion in K\n", + "Cp = 0.24\t\t\t\t\t#Specific heat at constant pressure in kJ/kg.K\n", + "Cv = 0.17\t\t\t\t\t#Specific heat at constant volume in kJ/kg.K\n", + "nv = 0.8\t\t\t\t\t#Nozzle efficiency\n", + "\n", + "\t\t\t\t\t\n", + "#Calculations\n", + "R = 427*(Cp-Cv)\t\t\t\t\t#Characteristic gas constant in kg.m/kg.K\n", + "g = (Cp/Cv)\t\t\t\t\t#Ratio of specific heats\n", + "V1 = (R*T1)/(p1*10**4)\t\t\t\t\t#Volume in cu.m per kg\n", + "V2 = (V1*(p1/p2)**(1/g))\t\t\t\t\t#Volume in cu.m per kg\n", + "Wd = (g/(g-1))*(p1*V1-p2*V2)*10**4\t\t\t\t\t#Work done in m.kg per kg\n", + "KE = (nv*Wd)\t\t\t\t\t#Kinetic energy at exit in m.kg per kg\n", + "v3 = math.sqrt(2*9.81*nv*Wd)\t\t\t\t\t#Velocity in m/s\n", + "T2 = (T1*(p2/p1)*(V2/V1))\t\t\t\t\t#Temperature in K\n", + "T3 = (((1-nv)*Wd)/(427*Cp))+T2\t\t\t\t\t#Temperature in K\n", + "V3 = (V2*(T3/T2))\t\t\t\t\t#Volume in cu.m per kg\n", + "qa = (V3/v3)*10**4\t\t\t\t\t#Discharge area unit rate of mass flow in cm**2\n", + "\n", + "\t\t\t\t\t\n", + "#Output\n", + "print 'Area of discharge per unit rate of mass flow is %3.2f sq.cm'%(qa)\n", + "\n" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "Area of discharge per unit rate of mass flow is 10.32 sq.cm\n" + ] + } + ], + "prompt_number": 5 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 26.5 Page no : 451" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "import math \n", + "\t\t\t\t\t\n", + "#Input data\n", + "p = 3.5\t\t\t\t\t#Pressure at the delivery is 3.5 times that at entrance\n", + "T = 1.15\t\t\t\t\t#Temperature rise during compression is 1.15 times that for frictionless adiabatic compression. In textbook it is given wrong as 1.5\n", + "T3 = 500.+273\t\t\t\t\t#Temperature of products of combustion in K\n", + "pa = 1.\t\t\t\t\t#Atmospheric pressure in kg/cm**2\n", + "Ta = 15.+273\t\t\t\t\t#Atmospheric temperature in K\n", + "Cp = 0.24\t\t\t\t\t#Specific heat at constant pressure in kJ/kg.K\n", + "g = 1.4\t\t\t\t\t#Ratio of specific heats\n", + "J = 427.\t\t\t\t\t#Mechanical equivalent of heat in kg.m/kcal\n", + "\n", + "\t\t\t\t\t\n", + "#Calculations\n", + "p2 = p*pa\t\t\t\t\t#Pressure in kg/cm**2\n", + "T2a = (Ta*(p2/pa)**((g-1)/g))\t\t\t\t\t#Temperature in K\n", + "T2 = (T2a-Ta)*T+Ta\t\t\t\t\t#Temperature in K\n", + "wcomp = (Cp*(T2-Ta))\t\t\t\t\t#Work done by compressor in kcal/kg\n", + "T5 = T3/(p2/pa)**((g-1)/g)\t\t\t\t\t#Temperature in K\n", + "dh35 = (Cp*(T3-T5))\t\t\t\t\t#Change in enthalpy in kcal/kg\n", + "dhnozzle = (dh35-wcomp)\t\t\t\t\t#Change in enthalpy of nozzle in kcal/kg\n", + "v5 = math.sqrt(2*9.81*J*dhnozzle)\t\t\t\t\t#Velocity at the nozzle exit in m/sec\n", + "Th = (v5/9.81)\t\t\t\t\t#Thrust in kg per kg of air/sec\n", + "\n", + "\t\t\t\t\t\n", + "#Output\n", + "print 'a) the power required to drive the compressor per kg of air per second is %3.1f kcal/kg \\\n", + "\\nb) Static thrust developed per kg of air per second is %3.1f kg'%(wcomp,Th)\n" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "a) the power required to drive the compressor per kg of air per second is 34.2 kcal/kg \n", + "b) Static thrust developed per kg of air per second is 43.4 kg\n" + ] + } + ], + "prompt_number": 6 + }, + { + "cell_type": "code", + "collapsed": false, + "input": [], + "language": "python", + "metadata": {}, + "outputs": [] + } + ], + "metadata": {} + } + ] +}
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