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diff --git a/Internal_Combustion_Engines_by_H._B._Keswani/ch23.ipynb b/Internal_Combustion_Engines_by_H._B._Keswani/ch23.ipynb new file mode 100755 index 00000000..bd824c81 --- /dev/null +++ b/Internal_Combustion_Engines_by_H._B._Keswani/ch23.ipynb @@ -0,0 +1,1070 @@ +{ + "metadata": { + "name": "", + "signature": "sha256:0f0f5140414de1792e9d5844fd5e51c3893bcfd2190a5a84bfb8220b6aa3a6fc" + }, + "nbformat": 3, + "nbformat_minor": 0, + "worksheets": [ + { + "cells": [ + { + "cell_type": "heading", + "level": 1, + "metadata": {}, + "source": [ + "Chapter 23 : Testing of Engines" + ] + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 23.1 Page no : 340" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "import math \n", + "\t\t\t\t\t\n", + "#Input data\n", + "n = 4.\t\t\t\t\t#Four cylinder engine\n", + "N = 1200.\t\t\t\t\t#Speed in r.p.m\n", + "BHP1 = 26.3\t\t\t\t\t#Brake horse power in B.H.P\n", + "T = 11.3\t\t\t\t\t#Average torque in kg\n", + "CV = 10000.\t\t\t\t\t#Calorific value of the fuel in kcal/kg\n", + "m = 270.\t\t\t\t\t#Flow rate in gm of petrol per B.H.P hour\n", + "\n", + "\t\t\t\t\t\n", + "#Calculations\n", + "BHP2 = (T*2*3.14*N)/4500\t\t\t\t\t#Average B.H.P on 3 cylinders \n", + "IHP = BHP1-BHP2\t\t\t\t\t#Average I.H.P of one cylinder\n", + "TIHP = (n*IHP)\t\t\t\t\t#Total I.H.P\n", + "p = ((m/1000)*BHP1)/TIHP\t\t\t\t\t#Petrol used in kg/I.H.P hr\n", + "nth = ((4500*60)/(427*p*CV))*100\t\t\t\t\t#Indicated Thermal efficiency in percent \n", + "\n", + "\t\t\t\t\t\n", + "#Output\n", + "print 'Thermal efficiency is %3.1f percent'%(nth)\n" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "Thermal efficiency is 26.3 percent\n" + ] + } + ], + "prompt_number": 1 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 23.2 Page no : 344" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "import math \n", + "n = 4\t\t\t\t\t#Four cylinder engine\n", + "d = 0.1\t\t\t\t\t#Diameter of piston in m\n", + "l = 0.15\t\t\t\t\t#Stroke in m\n", + "RPM = 1600\t\t\t\t\t#Speed in r.p.m\n", + "ap = (5.76*10**-4)\t\t\t\t\t#Area of positive loop of indicator diagram in sq.m\n", + "an = (0.26*10**-4)\t\t\t\t\t#Area of negative loop of indicator diagram in sq.m\n", + "L = 0.055\t\t\t\t\t#Length of the indicator diagram in m\n", + "k = (3.5/10**-6)\t\t\t\t\t#Spring constant in kg/m**2 per m\n", + "\n", + "\t\t\t\t\t\n", + "#Calculations\n", + "NA = (ap-an)\t\t\t\t\t#Net area of the indicator diagram in sq.m\n", + "h = (NA/L)\t\t\t\t\t#Average height of diagram in m\n", + "Pm = (h*k)\t\t\t\t\t#Mean effective pressure in kg/m**2\n", + "IHP = (Pm*l*(3.14/4)*d**2*RPM*n)/4500\t\t\t\t\t#Indicated Horse Power\n", + "\n", + "\t\t\t\t\t\n", + "#Output\n", + "print 'Indicated horse power of a four cylinder two stroke petrol engine is %3.1f'%(IHP)\n" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "Indicated horse power of a four cylinder two stroke petrol engine is 58.6\n" + ] + } + ], + "prompt_number": 2 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 23.3 Page no : 348" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "import math \n", + "\t\t\t\t\t\n", + "#Input data\n", + "n = 6\t\t\t\t\t#Number of cylinders\n", + "d = 0.089\t\t\t\t\t#Bore in m\n", + "l = 0.1016\t\t\t\t\t#Stroke in m\n", + "vc = 3.183\t\t\t\t\t#Compression ratio\n", + "rn = 55\t\t\t\t\t#Relative efficiency in percent\n", + "m = 0.218\t\t\t\t\t#Petrol consumption in kg/hp.hr\n", + "Pm = (8.4/10**-4)\t\t\t\t\t#Indicated mean effective pressure in kg/m**2\n", + "N = 2500\t\t\t\t\t#Speed in r.p.m\n", + "\n", + "\t\t\t\t\t\n", + "#Calculations\n", + "an = (1-(1/(vc-1)))*100\t\t\t\t\t#Air standard efficiency in percent\n", + "nth = (rn*an)/100\t\t\t\t\t#Thermal efficiency in percent\n", + "CV = ((4500*60)/(m*(nth/100)*427))\t\t\t\t\t#Calorific value in kcal/kg\n", + "IHP = ((Pm*(3.14/4)*d**2*l*N*n)/(4500*2))\t\t\t\t\t#Indicated horse power\n", + "p = (m*IHP)\t\t\t\t\t#Petrol consumption in kg/hour\n", + "\n", + "\t\t\t\t\t\n", + "#Output\n", + "print '1) The calorific value of petrol is %i kcal/kg \\\n", + "\\n2) Corresponding petrol consumption is %3.1f kg/hour'%(CV,p)\n" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "1) The calorific value of petrol is 9731 kcal/kg \n", + "2) Corresponding petrol consumption is 19.3 kg/hour\n" + ] + } + ], + "prompt_number": 3 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 23.4 Page no : 349" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "import math \n", + "\t\t\t\t\t\n", + "#Input data\n", + "n = 4.\t\t\t\t\t#Number of cylinders\n", + "d = 0.2\t\t\t\t\t#Bore in m\n", + "l = 0.3\t\t\t\t\t#Stroke in m\n", + "N = 300.\t\t\t\t\t#Speed in r.p.m\n", + "af = 5.\t\t\t\t\t#Air to fuel ratio by volume. In textbook it is given as 4 which is wrong\n", + "nv = 78.\t\t\t\t\t#Volumetric efficiency in percent\n", + "CV = 2200.\t\t\t\t\t#Calorific value in kcal/cu.m at N.T.P\n", + "bth = 23.\t\t\t\t\t#Brake thermal efficiency in percent\n", + "\n", + "\t\t\t\t\t\n", + "#Calculations\n", + "Vs = ((3.14/4)*d**2*l)\t\t\t\t\t#Swept volume in cu.m\n", + "c = ((nv/100)*Vs)\t\t\t\t\t#Total charge per stroke in cu.m\n", + "Vg = ((c/af)*N)\t\t\t\t\t#Volume of gas used per min in cu.m at N.T.P\n", + "q = (CV*Vg)\t\t\t\t\t#Heat supplied in kcal/min\n", + "BHP = ((bth/100)*q)/(4500./427)\t\t\t\t\t#Brake horse power\n", + "\n", + "\t\t\t\t\t\n", + "#Output\n", + "print 'The volume of gas used per min is %3.3f cu.m at N.T.P \\\n", + "\\nB.H.P of engine is %3.1f'%(Vg,BHP)\n" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "The volume of gas used per min is 0.441 cu.m at N.T.P \n", + "B.H.P of engine is 21.2\n" + ] + } + ], + "prompt_number": 5 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 23.5 Page no : 353" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "import math \n", + "\t\t\t\t\t\n", + "#Input data\n", + "d = 20.\t\t\t\t\t#Bore in cm\n", + "l = 37.5\t\t\t\t\t#Stroke in cm\n", + "r = 6.\t\t\t\t\t#Compression ratio\n", + "IPm = 5.\t\t\t\t\t#Indicated Mean effective pressure in kg/cm**2\n", + "ag = 6.\t\t\t\t\t#Air to gas ratio\n", + "CV = 3070.\t\t\t\t\t#Calorific value of gas in kcal/cu.m\n", + "T = 75.+273\t\t\t\t\t#Temperature in K\n", + "p = 0.975\t\t\t\t\t#Pressure in kg/cm**2\n", + "RPM = 240.\t\t\t\t\t#Speed in r.p.m\n", + "g = 1.4\t\t\t\t\t#Ratio of specific heats\n", + "\n", + "\t\t\t\t\t\n", + "#Calculations\n", + "Vs = (3.14/4)*d**2*l\t\t\t\t\t#Stroke Volume in cu.m\n", + "Vg = (1/(r+1))*Vs\t\t\t\t\t#Volume of gas in cylinder in cu.m per cycle\n", + "x = (Vg*(p/1.03)*(273/T))\t\t\t\t\t#Volume at 'Vg' cu.m at 'p' kg/cm**2 and 'T' K are equivalent in cu.m\n", + "q = (CV*x)/10**6\t\t\t\t\t#Heat added in kcal per cycle\n", + "IHP = (IPm*(Vs/100)*(RPM/2))/4500\t\t\t\t\t#Indicated horse power\n", + "nth = ((IHP*4500)/(427*q*(RPM/2)))*100\t\t\t\t\t#Thermal efficiency in percent\n", + "na = (1-(1/r**(g-1)))*100\t\t\t\t\t#Air standard efficiency in percent\n", + "rn = (nth/na)*100\t\t\t\t\t#Relative effeciency in percent\n", + "\n", + "\t\t\t\t\t\n", + "#Output\n", + "print 'The thermal efficiency is %3.1f percent \\\n", + "\\nThe relative efficiency is %3.1f percent \\\n", + "\\nIndicated horese power is %3.1f H.P'%(nth,rn,IHP)\n" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "The thermal efficiency is 36.0 percent \n", + "The relative efficiency is 70.3 percent \n", + "Indicated horese power is 15.7 H.P\n" + ] + } + ], + "prompt_number": 7 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 23.6 Page no : 356" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "import math \n", + "\t\t\t\t\t\n", + "#Input data\n", + "n = 4\t\t\t\t\t#Number of cylinders\n", + "d = 6.25\t\t\t\t\t#Diametre in cm\n", + "l = 9.5\t\t\t\t\t#Stroke in cm\n", + "t = 678\t\t\t\t\t#Torque in kg.m\n", + "N = 3000\t\t\t\t\t#Speed in r.p.m\n", + "Vc = 60\t\t\t\t\t#Clearance volume in c.c\n", + "be = 0.5\t\t\t\t\t#Brake efficiency ratio based on the air standard cycle\n", + "CV = 10000\t\t\t\t\t#Calorific value in kcal/kg\n", + "g = 1.4\t\t\t\t\t#Ratio of specific heats\n", + "\n", + "\t\t\t\t\t\n", + "#Calculations\n", + "Vs = (3.14/4)*d**2*l\t\t\t\t\t#Stroke volume in c.c per cylinder\n", + "r = ((Vs+Vc)/Vc)\t\t\t\t\t#Compression ratio\n", + "na = (1-(1/r**(g-1)))\t\t\t\t\t#Air standard efficiency\n", + "bth = (be*na)*100\t\t\t\t\t#Brake thermal efficiency in percent\n", + "bhp = ((t/100)*2*3.14*N)/4500\t\t\t\t\t#B.H.P in H.P\n", + "q = (bhp*(4500/427))/(bth/100)\t\t\t\t\t#Heat supplied in kcal/min\n", + "F = (q*60)/CV\t\t\t\t\t#Fuel consumption in kg/hour\n", + "P = (bhp*4500*2*100)/(n*Vs*N)\t\t\t\t\t#pressure in kg/cm**2\n", + "\n", + "\t\t\t\t\t\n", + "#Output\n", + "print 'The fuel consumption is %3.2f kg/hour \\\n", + "\\nThe brake mean effective pressure is %3.2f kg/cm**2'%(F,P)\n" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "The fuel consumption is 5.95 kg/hour \n", + "The brake mean effective pressure is 6.47 kg/cm**2\n" + ] + } + ], + "prompt_number": 8 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 23.7 Page no : 360" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "import math \n", + "\t\t\t\t\t\n", + "#Input data\n", + "n = 1.\t\t\t\t\t#Number of cylinders\n", + "t = 30.\t\t\t\t\t#Trail time in min\n", + "m = 5.6\t\t\t\t\t#Oil consumption in l\n", + "CV = 9980.\t\t\t\t\t#Calorific value of oil in kcal/kg\n", + "g = 0.8\t\t\t\t\t#Specific gravity of oil \n", + "a = 8.35\t\t\t\t\t#Average area of indicator diagram in sq.cm\n", + "l = 8.4\t\t\t\t\t#Length of the indicator diagram in cm\n", + "is1 = 5.5\t\t\t\t\t#Indicator spring scale\n", + "L = 147.5\t\t\t\t\t#Brake load in kg\n", + "sp = 20.\t\t\t\t\t#Spring balance reading in kg\n", + "d = 1.5\t\t\t\t\t#Effective brake wheel diameter in m\n", + "N = 200.\t\t\t\t\t#Speed in r.p.m\n", + "cyd = 30.\t\t\t\t\t#Cylinder diameter in cm\n", + "l1 = 45.\t\t\t\t\t#Stroke in cm\n", + "mw = 11.\t\t\t\t\t#Jacket cooling water in kg/min\n", + "Tc = 35.+273\t\t\t\t\t#Temperature rise of cooling water in K\n", + "\n", + "\t\t\t\t\t\n", + "#Calculations\n", + "mp = (a/l)*is1\t\t\t\t\t#Mean effective pressure\n", + "ihp = ((mp*(l1/100)*(3.14/4)*cyd**2*(N/2))/4500)\t\t\t\t\t#Indicated horse power in h.p\n", + "bhp = (L*3.14*d*N)/4500\t\t\t\t\t#Brake horse power in h.p\n", + "nm = (bhp/ihp)*100\t\t\t\t\t#Mechanical efficiency in percent\n", + "F = (m*(60/t)*g)\t\t\t\t\t#Fuel consumption in kg/hour\n", + "Fc = (F/bhp)\t\t\t\t\t#Specific fuel consumption in kg/B.H.P/hour\n", + "ith = ((ihp*(4500./427))/((F/60)*CV))*100\t\t\t\t\t#Indicated thermal efficiency in percent\n", + "\n", + "\t\t\t\t\t\n", + "#Output\n", + "print 'a) I.H.P is %3.1f \\\n", + "\\nb) B.H.P is %3.1f \\\n", + "\\nc) Mechanical efficiency is %3.1f percent \\\n", + "\\nd) Specific fuel consumption is %3.2f kg/B.H.P/hour \\\n", + "\\ne) Indicated thermal efficiency is %3.1f percent'%(ihp,bhp,nm,Fc,ith)\n" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "a) I.H.P is 38.6 \n", + "b) B.H.P is 30.9 \n", + "c) Mechanical efficiency is 79.9 percent \n", + "d) Specific fuel consumption is 0.29 kg/B.H.P/hour \n", + "e) Indicated thermal efficiency is 27.3 percent\n" + ] + } + ], + "prompt_number": 11 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 23.8 Page no : 361" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "import math \n", + "\t\t\t\t\t\n", + "#Input data\n", + "d = 15.\t\t\t\t\t#Diameter in cm. In textbook it is given wrong as 39\n", + "l = 45.\t\t\t\t\t#Stroke in cm\n", + "f = 9.5\t\t\t\t\t#Total fuel used in litres\n", + "CV = 10500.\t\t\t\t\t#Calorific value in kcal/kg\n", + "n = 12624.\t\t\t\t\t#Total no. of revolutions\n", + "imep = 7.24\t\t\t\t\t#Gross i.m.e.p in kg/cm**2\n", + "pimep = 0.34\t\t\t\t\t#Pumping i.m.e.p in kg/cm**2\n", + "L = 150.\t\t\t\t\t#Net load on brake in kg\n", + "db = 1.78\t\t\t\t\t#Diameter of the brake wheel drum in m\n", + "dr = 4.\t\t\t\t\t#Diameter of rope in cm\n", + "cw = 545.\t\t\t\t\t#Cooling water circulated in litres\n", + "Tc = 45.\t\t\t\t\t#Cooling water temperature rise in degree C\n", + "g = 0.8\t\t\t\t\t#Specific gravity of oil\n", + "\n", + "\t\t\t\t\t\n", + "#Calculations\n", + "ihp = ((imep-pimep)*(l/100)*3.14*d**2*n)/(4500*60)\t\t\t\t\t#I.H.P in h.p\n", + "q = (f*g*CV)/60\t\t\t\t\t#Heat supplied in kcal/min\n", + "bhp = (L*3.14*(db+(dr/100))*n)/(4500*60)\t\t\t\t\t#B.H.P in h.p\n", + "qbhp = (bhp*4500)/427\t\t\t\t\t#Heat equivalent of B.H.P in kcal/min\n", + "qw = (cw*Tc)/60\t\t\t\t\t#Heat lost to jacket cooling water in kcal/min\n", + "dq = (q-(qbhp+qw))\t\t\t\t\t#Heat unaccounted in kcal/min\n", + "\n", + "\t\t\t\t\t\n", + "#Output\n", + "print 'Heat supplied is %3.0f kcal/min \\\n", + "\\nHeat equivalent of B.H.P is %3.0f kcal/min \\\n", + "\\nHeat lost to jacket cooling water is %3.0f kcal/min \\\n", + "\\nHeat unaccounted is %3.0f kcal/min'%(q,qbhp,qw,dq)\n" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "Heat supplied is 1330 kcal/min \n", + "Heat equivalent of B.H.P is 422 kcal/min \n", + "Heat lost to jacket cooling water is 409 kcal/min \n", + "Heat unaccounted is 499 kcal/min\n" + ] + } + ], + "prompt_number": 12 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 23.9 Page no : 364" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "import math \n", + "\t\t\t\t\t\n", + "#Input data\n", + "d = 27.\t\t\t\t\t#Diameter in cm\n", + "l = 45.\t\t\t\t\t#Stroke in cm\n", + "db = 1.62\t\t\t\t\t#Effective diameter of the brake in m\n", + "t = (38.*60+30)\t\t\t\t\t#Test duration in sec\n", + "CV = 4650.\t\t\t\t\t#Calorific value in kcal/m**3 at N.T.P\n", + "n = 8080.\t\t\t\t\t#Total no. of revolutions\n", + "en = 3230.\t\t\t\t\t#Total number of explosions\n", + "p = 5.75\t\t\t\t\t#Mean effective pressure in kg/cm**2\n", + "V = 7.7\t\t\t\t\t#Gas used in m**3\n", + "T = 15.+273\t\t\t\t\t#Atmospheric temperature in K\n", + "pg = 135.\t\t\t\t\t#pressure of gas in mm of water above atmospheric pressure\n", + "hb = 750.\t\t\t\t\t#Height of barometer in mm of Hg\n", + "L = 92.\t\t\t\t\t#Net load on brake in kg\n", + "w = 183.\t\t\t\t\t#Weigh of jacket cooling water in kg\n", + "Tc = 47.\t\t\t\t\t#Cooling water temperature rise in degree C\n", + "\n", + "\t\t\t\t\t\n", + "#Calculations\n", + "ihp = (p*(l/100)*(3.14/4)*d**2*en)/(4500*(t/60))\t\t\t\t\t#I.H.P in h.p\n", + "bhp = (L*3.14*db*n)/(4500*(t/60))\t\t\t\t\t#B.H.P in h.p\n", + "pa = (hb+(pg/13))\t\t\t\t\t#Pressure of gas supplied in mm of Hg\n", + "Vg = (V*(273/T)*(pa/760))\t\t\t\t\t#Volume of gas used at N.T.P in m**3\n", + "q = (Vg*CV)/(t/60)\t\t\t\t\t#Heat supplied per minute in kcal\n", + "qbhp = (bhp*4500)/427\t\t\t\t\t#Heat equivalent of B.H.P in kcal/min\n", + "qc = (w/(t/60))*Tc\t\t\t\t\t#Heat lost to jacket cooling water in kcal/min\n", + "qra = (q-(qbhp+qc))\t\t\t\t\t#Heat lost to exhaust, etc in kcal/min\n", + "\n", + "\t\t\t\t\t\n", + "#Output\n", + "print 'Heat supplied is %3.1f kcal/min \\\n", + "\\nHeat equivalent of B.H.P is %3.0f kcal/min \\\n", + "\\nHeat lost to jacket cooling water is %3.1f kcal/min \\\n", + "\\nHeat lost to exhaust radiation etc. is %3.1f kcal/min'%(q,qbhp,qc,qra)\n" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "Heat supplied is 882.0 kcal/min \n", + "Heat equivalent of B.H.P is 230 kcal/min \n", + "Heat lost to jacket cooling water is 223.4 kcal/min \n", + "Heat lost to exhaust radiation etc. is 428.6 kcal/min\n" + ] + } + ], + "prompt_number": 14 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 23.10 Page no : 366" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "import math \n", + "\t\t\t\t\t\n", + "#Input data\n", + "d = 25.\t\t\t\t\t#Bore in cm\n", + "l = 50.\t\t\t\t\t#Stroke in cm\n", + "N = 240.\t\t\t\t\t#Speed in r.p.m\n", + "n = 100.\t\t\t\t\t#Number of times fires per minute\n", + "qc = 0.3\t\t\t\t\t#Quantity of coal gas used in cu.m per minute\n", + "h = 100.\t\t\t\t\t#Head in mm of water\n", + "bp = 1.03\t\t\t\t\t#Barometric pressure in kg/cm**2\n", + "T = 15.+273\t\t\t\t\t#Temperature in K\n", + "ma = 2.82\t\t\t\t\t#Mass of air used in kg per minute\n", + "R = 29.45\t\t\t\t\t#Characteristic gas constant in kg.m/kg.K\n", + "\n", + "\t\t\t\t\t\n", + "#Calculations\n", + "gp = (bp+(100/13.6)*(bp/76))\t\t\t\t\t#Gas pressure in kg/cm**2\n", + "Vc = (qc*(gp/bp)*(273/T))\t\t\t\t\t#Volume of coal gas at N.T.P in cu.m per minute\n", + "Vce = (Vc/n)\t\t\t\t\t#Volume of coal gas per explosion in cu.m at N.T.P\n", + "va = (ma*R*273)/(bp*10**4)\t\t\t\t\t#Volume of air taken in at N.T.P in cu.m per min\n", + "V = ((va-(((N/2)-n)*Vce))/(N/2))\t\t\t\t\t#Volume in cu.m\n", + "tV = (V+Vce)\t\t\t\t\t#Total volume of charge in cu.m at N.T.P\n", + "Vs = ((3.14/4)*(d**2*l)*10**-6)\t\t\t\t\t#Swept volume in cu.m\n", + "nv = (tV/Vs)*100\t\t\t\t\t#Volumetric efficiency in percent\n", + "\n", + "\t\t\t\t\t\n", + "#Output\n", + "print 'a) the charge of air per working cycle as measured at N.T.P is %3.5f cu.m \\\n", + "\\nb) the volumetric efficiency is %3.1f percent'%(tV,nv)\n" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "a) the charge of air per working cycle as measured at N.T.P is 0.02094 cu.m \n", + "b) the volumetric efficiency is 85.4 percent\n" + ] + } + ], + "prompt_number": 15 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 23.11 Page no : 368" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "import math \n", + "\t\t\t\t\t\n", + "#Input data\n", + "d = 18.\t\t\t\t\t#Diameter in cm\n", + "l = 24.\t\t\t\t\t#Stroke in cm\n", + "t = 30.\t\t\t\t\t#Duration of trail in min\n", + "r = 9000.\t\t\t\t\t#Total number of revolutins\n", + "e = 4445.\t\t\t\t\t#Total number of explosions\n", + "mep = 5.85\t\t\t\t\t#Mean effective pressure in kg/cm**2\n", + "Nl = 40.\t\t\t\t\t#Net load on brake wheel in kg\n", + "ed = 1.\t\t\t\t\t#Effective diameter of brake wheel in meter\n", + "tg = 2.3\t\t\t\t\t#Total gas used at N.T.P in m**3\n", + "CV = 4600.\t\t\t\t\t#Calorific value of gas in kcal/m**3 at N.T.P\n", + "ta = 36.\t\t\t\t\t#Total air used in m**3\n", + "pa = 720.\t\t\t\t\t#Pressure of air in mm of Hg\n", + "Ta = 18.+273\t\t\t\t\t#Temperature of air in K\n", + "da = 1.293\t\t\t\t\t#Density of air at N.T.P in kg/m**3\n", + "Te = 350.+273\t\t\t\t\t#Temperature of exhaust gases in K\n", + "Tr = 18.+273\t\t\t\t\t#Room temperature in K\n", + "Cp = 0.24\t\t\t\t\t#Specific heat of exhaust gases in kJ/kg.K\n", + "twc = 81.5\t\t\t\t\t#Total weight of cylinder jacket cooling water in kg\n", + "dT = 33.\t\t\t\t\t#Rise in temperature of jacket cooling water in degree C\n", + "R = 29.45\t\t\t\t\t#Characteristic gas constant in kg.m/kg.degree C\n", + "\n", + "\t\t\t\t\t\n", + "#Calculations\n", + "ihp = (mep*(l/100)*(3.14/4)*d**2*(e/t))/4500\t\t\t\t\t#Indicated horse power in h.p\n", + "bhp = (Nl*3.14*r*ed)/(4500*t)\t\t\t\t\t#Brake horse power in h.p\n", + "qs = (tg/t)*CV\t\t\t\t\t#Heat supplied at N.T.P in kcal\n", + "qbhp = (bhp*4500)/427\t\t\t\t\t#Heat equivalent of B.H.P in kcal/min\n", + "ql = (twc/t)*dT\t\t\t\t\t#Heat lost to cylinder jacket cooling water in kcal/min\n", + "VA = (ta*(273/Ta)*(pa/760))\t\t\t\t\t#Volume of air used at N.T.P in m**3\n", + "WA = (VA*da)/t\t\t\t\t\t#Weight of air used per min in kg\n", + "WG = (1.03*tg*10**4)/(R*273)\t\t\t\t\t#Weight of gas in kg\n", + "Wg = (WG/t)\t\t\t\t\t#Weight of gas per minute in kg\n", + "We = (WA+Wg)\t\t\t\t\t#Total weight of exhaust gases in kg\n", + "qle = (We*(Te-Tr)*Cp)\t\t\t\t\t#Heat lost of exhaust gases in kcal/min\n", + "qra = (qs-(qbhp+ql+qle))\t\t\t\t\t#Heat lost by radiation in kcal/min\n", + "nm = (bhp/ihp)*100\t\t\t\t\t#Mechanical efficiency in percent\n", + "ith = ((ihp*4500)/(427*qs))*100\t\t\t\t\t#Indicated thermal efficiency in percent\n", + "\n", + "\t\t\t\t\t\n", + "#Output\n", + "print ' HEAT BALANCE SHEET ------------------ \\\n", + "\\nHeat supplied per minute is %3.1f kcal/min \\\n", + "\\nHeat expenditure kcal per minute \\\n", + "\\n1.Heat equivalent of B.H.P is %3.1f \\\n", + "\\n2.Heat lost to jacket cooling water is %3.1f \\\n", + "\\n3.Heat lost in exhaust gases is %3.1f \\\n", + "\\n4.Heat lost by radiation, etc, is %3.1f \\\n", + "\\n-------- %3.1f --------'%(qs,qbhp,ql,qle,qra,qs)\n" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + " HEAT BALANCE SHEET ------------------ \n", + "Heat supplied per minute is 352.7 kcal/min \n", + "Heat expenditure kcal per minute \n", + "1.Heat equivalent of B.H.P is 88.2 \n", + "2.Heat lost to jacket cooling water is 89.7 \n", + "3.Heat lost in exhaust gases is 117.7 \n", + "4.Heat lost by radiation, etc, is 57.1 \n", + "-------- 352.7 --------\n" + ] + } + ], + "prompt_number": 16 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 23.12 Page no : 372" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "import math \n", + "\t\t\t\t\t\n", + "#Input data\n", + "gu = 0.135\t\t\t\t\t#Gas used in m**3/min at N.T.P\n", + "CV = 3990\t\t\t\t\t#Calorific value of gas in kcal/m**3 at N.T.P\n", + "dg = 0.64\t\t\t\t\t#Density of gas in kg/m**3 at N.T.P\n", + "au = 1.52\t\t\t\t\t#Air used in kg/min\n", + "C = 0.24\t\t\t\t\t#Specific heat of exhaust gases in kJ/kg.K\n", + "Te = 397+273\t\t\t\t\t#Temperature of exhaust gases in K\n", + "Tr = 17+273\t\t\t\t\t#Room temperature in K\n", + "cw = 6\t\t\t\t\t#Cooling water per minute in kg\n", + "rT = 27.5\t\t\t\t\t#Rise in temperature in degree C\n", + "ihp = 12.3\t\t\t\t\t#Indicated horse power in h.p\n", + "bhp = 10.2\t\t\t\t\t#Brake horse power in h.p\n", + "\n", + "\t\t\t\t\t\n", + "#Calculations\n", + "qs = (gu*CV*60)\t\t\t\t\t#Heat supplied in kcal/hour\n", + "qbhp = ((bhp*4500*60)/427)\t\t\t\t\t#Heat equivalent of B.H.P in kcal/hr\n", + "ql = (cw*60*rT)\t\t\t\t\t#Heat lost in jacket cooling water in kcal/hr\n", + "mg = (gu*dg)\t\t\t\t\t#Mass of gas used per minute in kg\n", + "me = (mg+au)\t\t\t\t\t#Mass of exhaust gases per minute in kg\n", + "qe = (me*C*(Te-Tr)*60)\t\t\t\t\t#Heat carried away by exhaust gases in kcal/hour\n", + "qun = (qs-(qbhp+ql+qe))\t\t\t\t\t#Heat unaccounted in kcal/hour\n", + "\n", + "\t\t\t\t\t\n", + "#Output\n", + "print 'Heat supplied is %3.0f kcal/hour \\\n", + "\\nHeat equivalent of B.H.P is %3.0f kcal/hr \\\n", + "\\nHeat lost in jacket cooling water is %3.0f kcal/hr \\\n", + "\\nHeat carried away by exhaust gases is %3.0f kcal/hour \\\n", + "\\nHeat unaccounted is %3.0f kcal/hour'%(qs,qbhp,ql,qe,qun)\n" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "Heat supplied is 32319 kcal/hour \n", + "Heat equivalent of B.H.P is 6450 kcal/hr \n", + "Heat lost in jacket cooling water is 9900 kcal/hr \n", + "Heat carried away by exhaust gases is 8790 kcal/hour \n", + "Heat unaccounted is 7179 kcal/hour\n" + ] + } + ], + "prompt_number": 17 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 23.13 Page no : 372" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "import math \n", + "\t\t\t\t\t\n", + "#Input data\n", + "n = 4.\t\t\t\t\t#Number of cylinders\n", + "r = 1.\t\t\t\t\t#Radius in metre\n", + "N = 1400.\t\t\t\t\t#Speed in r.p.m\n", + "bl = 14.5\t\t\t\t\t#Net brake load in kg\n", + "P = [9.8,10.1,10.3,10]\t\t\t\t\t#Loads on the brake in kg\n", + "d = 9.\t\t\t\t\t#Bore in cm\n", + "l = 12.\t\t\t\t\t#Stroke in cm\n", + "\n", + "\t\t\t\t\t\n", + "#Calculations\n", + "bhp = (bl*2*3.14*r*N)/4500\t\t\t\t\t#Brake horse power in h.p\n", + "bhp1 = (P[0]*2*3.14*r*N)/4500\t\t\t\t\t#Brake horse power in h.p\n", + "bhp2 = (P[1]*2*3.14*r*N)/4500\t\t\t\t\t#Brake horse power in h.p\n", + "bhp3 = (P[2]*2*3.14*r*N)/4500\t\t\t\t\t#Brake horse power in h.p\n", + "bhp4 = (P[3]*2*3.14*r*N)/4500\t\t\t\t\t#Brake horse power in h.p\n", + "ihp1 = bhp-bhp1\t\t\t\t\t#Indicated horse power in h.p\n", + "ihp2 = bhp-bhp2\t\t\t\t\t#Indicated horse power in h.p\n", + "ihp3 = bhp-bhp3\t\t\t\t\t#Indicated horse power in h.p\n", + "ihp4 = bhp-bhp4\t\t\t\t\t#Indicated horse power in h.p\n", + "ihp = (ihp1+ihp2+ihp3+ihp4)\t\t\t\t\t#Indicated horse power in h.p\n", + "nm = (bhp/ihp)*100\t\t\t\t\t#Mechanical efficiency in percent\n", + "pm = ((4500*bhp)/((l/100)*(3.14/4)*d**2*(N/2)))\t\t\t\t\t#Brake mean effective pressure in kg/cm**2\n", + "\n", + "\t\t\t\t\t\n", + "#Output\n", + "print 'I.H.P is %3.1f h.p \\\n", + "\\nMechanical efficiency is %3.1f percent \\\n", + "\\nBrake mean effective pressure is %3.0f kg/cm**2'%(ihp,nm,pm)\n" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "I.H.P is 34.8 h.p \n", + "Mechanical efficiency is 81.5 percent \n", + "Brake mean effective pressure is 24 kg/cm**2\n" + ] + } + ], + "prompt_number": 20 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 23.14 Page no : 374" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "import math \n", + "\t\t\t\t\t\n", + "#Input data\n", + "N = 350\t\t\t\t\t#Speed in r.p.m\n", + "L = 60\t\t\t\t\t#Net brake load in kg\n", + "mep = 2.75\t\t\t\t\t#Mean effective pressure in kg/cm**2\n", + "oc = 4.25\t\t\t\t\t#Oil consumption in kg/hour\n", + "jcw = 490\t\t\t\t\t#Jacket cooling water in kg/hour\n", + "Tw = [20+273,45+273]\t\t\t\t\t#Temperature of jacket water at inlet and outlet in K\n", + "au = 31.5\t\t\t\t\t#Air used per kg of oil in kg\n", + "Ta = 20+273\t\t\t\t\t#Temperature of air in the test room in K\n", + "Te = 390+273\t\t\t\t\t#Temperature of exhaust gases in K\n", + "d = 22\t\t\t\t\t#Cylinder diameter in cm\n", + "l = 28\t\t\t\t\t#Stroke in cm\n", + "bd = 1\t\t\t\t\t#Effective brake diameter in m\n", + "CV = 10500\t\t\t\t\t#Calorific value of oil in kcal/kg\n", + "pH2 = 15\t\t\t\t\t#Proportion of hydrogen in fuel oil in percent\n", + "C = 0.24\t\t\t\t\t#Mean specific heat of dry exhaust gases\n", + "Cs = 9.5\t\t\t\t\t#Specific heat of steam in kJ/kg.K\n", + "\n", + "\t\t\t\t\t\n", + "#Calculations\n", + "ibp = (mep*(l/100)*(3.14/4)*d**2*N)/4500\t\t\t\t\t#Indicated brake power in h.p\n", + "bhp = (L*3.14*N*bd)/4500\t\t\t\t\t#Brake horse power in h.p\n", + "qs = (oc*CV)/60\t\t\t\t\t#Heat supplied per minute in kcal\n", + "qbhp = (bhp*4500)/427\t\t\t\t\t#Heat equivalent of B.H.P in kcal/min\n", + "pqbhp = (qbhp/qs)*100\t\t\t\t\t#Percenatge of heat\n", + "ql = (jcw/60)*(Tw[1]-Tw[0])\t\t\t\t\t#Heat lost to cooling water in kcal/min\n", + "pql = (ql/qs)*100\t\t\t\t\t#Percenatge of heat\n", + "wH2O = (9*(pH2/100)*(oc/60))\t\t\t\t\t#Weight of H2O produced per kg of fuel burnt in kg/min\n", + "twe = (oc*(au+1))/60\t\t\t\t\t#Total weight of wet exhaust gases per minute in kg\n", + "twd = (twe-wH2O)\t\t\t\t\t#Weight of dry exhaust gases per minute in kg\n", + "qle = (twd*C*(Te-Ta))\t\t\t\t\t#Heat lost to dry exhaust gases/min in kcal\n", + "pqle = (qle/qs)*100\t\t\t\t\t#Percenatge of heat\n", + "qx = (100+538.9+0.5*(Te-373))\t\t\t\t\t#Heat in kcal/kg\n", + "qst = (wH2O*qx)\t\t\t\t\t#Heat to steam in kcal/min\n", + "pqst = (qst/qs)*100\t\t\t\t\t#Percenatge of heat\n", + "qra = (qs-(qbhp+ql+qle+qst))\t\t\t\t\t#Heat lost by radiation in kcal/min\n", + "pqra = (qra/qs)*100\t\t\t\t\t#Percenatge of heat\n", + "\n", + "\t\t\t\t\t\n", + "#Output\n", + "print ' HEAT BALANCE SHEET ------------------ \\\n", + "\\nHeat supplied per minute is %3.0f kcal/min 100 percent \\\n", + "\\nHeat expenditure kcal per minute percent \\\n", + "\\n1.Heat equivalent of B.H.P is %3.1f %3.1f \\\n", + "\\n2.Heat lost to cooling water is %3.0f %3.1f \\\n", + "\\n3.Heat lost to dry exhaust gases is %3.1f %3.1f \\\n", + "\\n4.Heat lost of steam in exhaust gases is %3.0f %3.1f \\\n", + "\\n5.Heat lost by radiation, etc., is %3.0f %3.1f \\\n", + "\\n ---------- Total %3.0f %3.0f ------------------'\\\n", + "%(qs,qbhp,pqbhp,ql,pql,qle,pqle,qst,pqst,qra,pqra,qs,(pqbhp+pql+pqle+pqst+pqra))\n", + "\n" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + " HEAT BALANCE SHEET ------------------ \n", + "Heat supplied per minute is 744 kcal/min 100 percent \n", + "Heat expenditure kcal per minute percent \n", + "1.Heat equivalent of B.H.P is 154.4 20.8 \n", + "2.Heat lost to cooling water is 200 26.9 \n", + "3.Heat lost to dry exhaust gases is 204.4 27.5 \n", + "4.Heat lost of steam in exhaust gases is 0 0.0 \n", + "5.Heat lost by radiation, etc., is 185 24.9 \n", + " ---------- Total 744 100 ------------------\n" + ] + } + ], + "prompt_number": 23 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 23.15 Page no : 376" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "import math \n", + "\t\t\t\t\t\n", + "#Input data\n", + "d = 20\t\t\t\t\t#Diameter in cm\n", + "l = 40\t\t\t\t\t#Stroke in cm\n", + "mep = 5.95\t\t\t\t\t#Mean effective pressure in kg/cm**2\n", + "bt = 41.5\t\t\t\t\t#Brake torque in kg.m\n", + "N = 250\t\t\t\t\t#Speed in r.p.m\n", + "oc = 4.2\t\t\t\t\t#Oil consumption in kg per hour\n", + "CV = 11300\t\t\t\t\t#Calorific value of fuel in kcal/kg\n", + "jcw = 4.5\t\t\t\t\t#Jacket cooling water in kg/min\n", + "rT = 45\t\t\t\t\t#Rise in temperature in degree C\n", + "au = 31\t\t\t\t\t#Air used in kg\n", + "Te = 420\t\t\t\t\t#Temperature of exhaust gases in degree C\n", + "Tr = 20\t\t\t\t\t#Room temperature in degree C\n", + "Cm = 0.24\t\t\t\t\t#Mean specific heat of exhaust gases in kJ/kg.K\n", + "\n", + "\t\t\t\t\t\n", + "#Calculations\n", + "ihp = (mep*(l/100)*(3.14/4)*d**2*(N/2))/4500\t\t\t\t\t#Indicated horse power in h.p\n", + "bhp = (bt*2*3.14*N)/4500\t\t\t\t\t#Brake horse power in h.p\n", + "q = (oc*CV)\t\t\t\t\t#Heat supplied in kcal/hour\n", + "qbhp = (bhp*4500*60)/427\t\t\t\t\t#Heat equivalent of B.H.P in kcal/hour\n", + "qfhp = ((ihp-bhp)*4500*60)/427\t\t\t\t\t#Heat equivalent F.H.P in kcal/hour\n", + "qc = (jcw*rT*60)\t\t\t\t\t#Heat lost in cooling water in kcal/hour\n", + "qe = (oc*32*Cm*(Te-Tr))\t\t\t\t\t#Heat lost in exhaust gases in kcal/hour\n", + "hu = (q-(qbhp+qfhp+qc+qe))\t\t\t\t\t#Heat unaccounted in kcal/hour\n", + "\n", + "\t\t\t\t\t\n", + "#Output\n", + "print 'Indicated horse power is %3.1f h.p \\\n", + "\\nBrake horse power is %3.2f h.p \\\n", + "\\nHeat supplied is %3.0f kcal/hour \\\n", + "\\nHeat equivalent of B.H.P is %3.0f kcal/hour \\\n", + "\\nHeat equivalent of F.H.P is %3.0f kcal/hour \\\n", + "\\nHeat lost in cooling water is %3.0f kcal/hour \\\n", + "\\nHeat lost in exhaust gases is %3.0f kcal/hour \\\n", + "\\nHeat unaccounted is %3.0f kcal/hour'%(ihp,bhp,q,qbhp,qfhp,qc,qe,hu)\n" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "Indicated horse power is 0.0 h.p \n", + "Brake horse power is 14.48 h.p \n", + "Heat supplied is 47460 kcal/hour \n", + "Heat equivalent of B.H.P is 9155 kcal/hour \n", + "Heat equivalent of F.H.P is -9155 kcal/hour \n", + "Heat lost in cooling water is 12150 kcal/hour \n", + "Heat lost in exhaust gases is 12902 kcal/hour \n", + "Heat unaccounted is 22408 kcal/hour\n" + ] + } + ], + "prompt_number": 24 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 23.16 Page no : 381" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "import math \n", + "\t\t\t\t\t\n", + "#Input data\n", + "ihp = 45.\t\t\t\t\t#Indicated horse power in h.p\n", + "bhp = 37.\t\t\t\t\t#Brake horse power in h.p\n", + "fu = 8.4\t\t\t\t\t#Fuel used in kg/hour\n", + "CV = 10000.\t\t\t\t\t#Calorific value in kcal/kg\n", + "Tc = [15.,70.]\t\t\t\t\t#Inlet and outlet temperatures of cylinders in degree C\n", + "cj = 7.\t\t\t\t\t#Rate of flow of cylinder jacket in kg/min\n", + "Tw = [15.,55.]\t\t\t\t\t#Inlet and outlet temperatures of water in degree C\n", + "rw = 12.5\t\t\t\t\t#Rate of water flow in kg per minute\n", + "Te = 82.\t\t\t\t\t#Final temperature of exhaust gases in degree C\n", + "Tr = 17.\t\t\t\t\t#Room temperature in degree C\n", + "af = 20.\t\t\t\t\t#Air fuel ratio\n", + "Cm = 0.24\t\t\t\t\t#Mean specific heat of exhaust gases in kJ/kg.K\n", + "\n", + "\t\t\t\t\t\n", + "#Calculations\n", + "q = (fu/60)*CV\t\t\t\t\t#Heat supplied in kcal/min\n", + "qbhp = (bhp*4500)/427\t\t\t\t\t#Heat equivalent of B.H.P in kcal/min\n", + "ql = (cj*(Tc[1]-Tc[0]))\t\t\t\t\t#Heat lost to cylinder jacket cooling water in kcal/min\n", + "qe = (rw*(Tw[1]-Tw[0]))\t\t\t\t\t#Heat lost by exhaust gases in kcal/min\n", + "qee = (Te-Tr)*Cm*(af+1)*fu/60\t\t\t\t\t#Heat of exhaust gas in kcal/min\n", + "te = (qe+qee)\t\t\t\t\t#Total heat lost to exhaust gases in kcal/min\n", + "hra = (q-(qbhp+ql+te))\t\t\t\t\t#Heat lost to radiation in kcal/min\n", + "ith = ((ihp*4500)/(427*q))*100\t\t\t\t\t#Indicated thermal efficiency in percent\n", + "bth = ((bhp*4500)/(427*q))*100\t\t\t\t\t#Brake thermal efficiency in percent\n", + "nm = (bhp/ihp)*100\t\t\t\t\t#Mechanical efficiency in percent\n", + "\n", + "\t\t\t\t\t\n", + "#Output\n", + "print 'Heat supplied is %3.0f kcal/min \\\n", + "\\nHeat equivalent of B.H.P is %3.0f kcal/min \\\n", + "\\nHeat lost to cylinder jacket cooling water is %3.0f kcal/min \\\n", + "\\nTotal heat lost to exhaust gases is %3.1f kcal/min \\\n", + "\\nHeat lost to radiation is %3.1f kcal/min \\\n", + "\\nIndicated thermal efficiency is %3.1f percent \\\n", + "\\nBrake thermal efficiency is %3.1f percent \\\n", + "\\nMechanical efficiency is %3.1f percent'%(q,qbhp,ql,te,hra,ith,bth,nm)\n" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "Heat supplied is 1400 kcal/min \n", + "Heat equivalent of B.H.P is 390 kcal/min \n", + "Heat lost to cylinder jacket cooling water is 385 kcal/min \n", + "Total heat lost to exhaust gases is 545.9 kcal/min \n", + "Heat lost to radiation is 79.2 kcal/min \n", + "Indicated thermal efficiency is 33.9 percent \n", + "Brake thermal efficiency is 27.9 percent \n", + "Mechanical efficiency is 82.2 percent\n" + ] + } + ], + "prompt_number": 26 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 23.17 Page no : 382" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "import math \n", + "\t\t\t\t\t\n", + "#Input data\n", + "Vs = 0.0015\t\t\t\t\t#Stroke volume in cu.m\n", + "rc = 5.5\t\t\t\t\t#Volume compression ratio\n", + "p2 = 8.\t\t\t\t\t#Pressure at the end of compression stroke in kg/cm**2\n", + "T2 = 350.+273\t\t\t\t\t#Temperature at the end of compression stroke in K\n", + "p3 = 25.\t\t\t\t\t#Pressure in kg/cm**2\n", + "x = (1./30)\t\t\t\t\t#Fraction of dismath.tance travelled by piston\n", + "pa = 1./16\t\t\t\t\t#Petrol air mixture ratio\n", + "R = 29.45\t\t\t\t\t#Characteristic gas constant in kg.m/kg degree C\n", + "CV = 10000.\t\t\t\t\t#Calorific value of fuel in kcal per kg\n", + "Cv = 0.23\t\t\t\t\t#Specific heat in kJ/kg.K\n", + "\n", + "\t\t\t\t\t\n", + "#Calculations\n", + "V2 = (Vs*10**6)/(rc-1)\t\t\t\t\t#Volume in c.c\n", + "V3 = (Vs*10**6)*x+V2\t\t\t\t\t#Volume in c.c\n", + "T3 = (T2*p3*V3)/(p2*V2)\t\t\t\t\t#Temperature in K\n", + "W = ((p3+p2)/2)*(V3-V2)\t\t\t\t\t#Workdone in kg.cm\n", + "mM = ((p2*V2)/(T2*R*100))\t\t\t\t\t#Mass of mixture present in kg\n", + "dE = (mM*Cv*(T3-T2))\t\t\t\t\t#Change in energy in kcal\n", + "q = (dE+(W/(427*100)))\t\t\t\t\t#Heat in kcal\n", + "qc = (1/(1+(1/pa)))*mM*CV \t\t\t\t\t#Heat in kcal\n", + "ql = (qc-q)/mM\t\t\t\t\t#Heat lost in kcal per kg of charge\n", + "\n", + "\t\t\t\t\t\n", + "#Output\n", + "print 'Heat lost per kg of charge during explosion is %3.0f kcal'%(ql)\n" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "Heat lost per kg of charge during explosion is 203 kcal\n" + ] + } + ], + "prompt_number": 28 + } + ], + "metadata": {} + } + ] +}
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