{ "metadata": { "name": "", "signature": "sha256:5906799cfbbbc1071564cbe6c16af88dcd0f4ba1965a4d189758faaa2356010c" }, "nbformat": 3, "nbformat_minor": 0, "worksheets": [ { "cells": [ { "cell_type": "heading", "level": 1, "metadata": {}, "source": [ "Chapter5-Inertia Force Analysis in Machines" ] }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Ex1-pg160" ] }, { "cell_type": "code", "collapsed": false, "input": [ "##CHAPTER 5 ILLUSRTATION 1 PAGE NO 160\n", "##TITLE:Inertia Force Analysis in Machines\n", "import math\n", "pi=3.141\n", "r=.3## radius of crank in m\n", "l=1.## length of connecting rod in m\n", "N=200.## speed of the engine in rpm\n", "n=l/r\n", "##===================\n", "w=2.*pi*N/60.## angular speed in rad/s\n", "\n", "teeta=math.acos((-n+((n**2)+4*2*1)**.5)/(2*2))*57.3## angle of inclination of crank in degrees\n", "Vp=w*r*(math.sin(teeta/57.3)+(math.sin((2*teeta)/57.3)/n))## maximum velocity of the piston in m/s\n", "print'%s %.1f %s'%('Maximum velocity of the piston = ',Vp,' m/s')\n", "print'%s %.2f %s'%('teeta',teeta,'')" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Maximum velocity of the piston = 7.0 m/s\n", "teeta 74.96 \n" ] } ], "prompt_number": 1 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Ex2-pg161" ] }, { "cell_type": "code", "collapsed": false, "input": [ "##CHAPTER 5 ILLUSRTATION 2 PAGE NO 161\n", "##TITLE:Inertia Force Analysis in Machines\n", "import math\n", "PI=3.141\n", "r=.3## length of crank in metres\n", "l=1.5## length of connecting rod in metres\n", "N=180.## speed of rotation in rpm\n", "teeta=40.## angle of inclination of crank in degrees\n", "##============================\n", "n=l/r\n", "w=2.*PI*N/60## angular speed in rad/s\n", "Vp=w*r*(math.sin(teeta/57.3)+math.sin((2.*teeta/57.3)/(2.*n)))## velocity of piston in m/s\n", "fp=w**2.*r*(math.cos(teeta/57.3)+math.cos(2.*teeta/57.3)/(2.*n))## acceleration of piston in m/s**2\n", "costeeta1=(-n+(n**2.+4.*2.*1.)**.5)/4.\n", "teeta1=math.acos(costeeta1)*(57.3)## position of crank from inner dead centre position for zero acceleration of piston\n", "##===========================\n", "print'%s %.1f %s %.1f %s %.1f %s'%('Velocity of Piston = ',Vp,' m/s'' Acceleration of piston =',fp,' m/s**2'' position of crank from inner dead centre position for zero acceleration of piston=',teeta1,' degrees')\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Velocity of Piston = 4.4 m/s Acceleration of piston = 83.5 m/s**2 position of crank from inner dead centre position for zero acceleration of piston= 79.3 degrees\n" ] } ], "prompt_number": 2 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Ex3-pg161" ] }, { "cell_type": "code", "collapsed": false, "input": [ "##CHAPTER 5 ILLUSRTATION 3 PAGE NO 161\n", "##TITLE:Inertia Force Analysis in Machines\n", "import math\n", "pi=3.141\n", "D=.3## Diameter of steam engine in m\n", "L=.5## length of stroke in m\n", "r=L/2.\n", "mR=100.## equivalent of mass of reciprocating parts in kg\n", "N=200.## speed of engine in rpm\n", "teeta=45## angle of inclination of crank in degrees\n", "p1=1.*10**6## gas pressure in N/m**2\n", "p2=35.*10**3## back pressure in N/m**2\n", "n=4.## ratio of crank radius to the length of stroke\n", "##=================================\n", "w=2.*pi*N/60## angular speed in rad/s\n", "Fl=pi/4.*D**2.*(p1-p2)## Net load on piston in N\n", "Fi=mR*w**2*r*(math.cos(teeta/57.3)+math.cos((2*teeta)/57.3)/(2*n))## inertia force due to reciprocating parts\n", "Fp=Fl-Fi## Piston effort\n", "T=Fp*r*(math.sin(teeta/57.3)+(math.sin((2*teeta)/57.3))/(2.*(n**2-(math.sin(teeta/57.3))**2)**.5))\n", "print'%s %.1f %s %.1f %s '%('Piston effort = ',Fp,' N' 'Turning moment on the crank shaft = ',T,' N-m')\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Piston effort = 60447.0 NTurning moment on the crank shaft = 12604.2 N-m \n" ] } ], "prompt_number": 3 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Ex4-pg162" ] }, { "cell_type": "code", "collapsed": false, "input": [ "##CHAPTER 5 ILLUSRTATION 4 PAGE NO 162\n", "##TITLE:Inertia Force Analysis in Machines\n", "import math\n", "pi=3.141\n", "D=.10## Diameter of petrol engine in m\n", "L=.12## Stroke length in m\n", "l=.25## length of connecting in m\n", "r=L/2.\n", "mR=1.2## mass of piston in kg\n", "N=1800.## speed in rpm\n", "teeta=25.## angle of inclination of crank in degrees\n", "p=680.*10**3## gas pressure in N/m**2\n", "n=l/r\n", "g=9.81## acceleration due to gravity\n", "##=======================================\n", "w=2.*pi*N/60.## angular speed in rpm\n", "Fl=pi/4.*D**2.*p## force due to gas pressure in N\n", "Fi=mR*w**2.*r*(math.cos(teeta/57.3)+math.cos((2*teeta)/57.3)/(n))## inertia force due to reciprocating parts in N\n", "Fp=Fl-Fi+mR*g## net force on piston in N\n", "Fq=n*Fp/((n**2-(math.sin(teeta/57.3))**2.)**.5)## resultant load on gudgeon pin in N\n", "Fn=Fp*math.sin(teeta/57.3)/((n**2-(math.sin(teeta/57.3))**2.)**.5)## thrust on cylinder walls in N\n", "fi=Fl+mR*g## inertia force of the reciprocating parts before the gudgeon pin load is reversed in N\n", "w1=(fi/mR/r/(math.cos(teeta/57.3)+math.cos((2*teeta)/57.3)/(n)))**.5\n", "N1=60.*w1/(2.*pi)\n", "print'%s %.1f %s %.1f %s %.1f %s %.1f %s '%('Net force on piston = ',Fp,' N'' Resultant load on gudgeon pin = ',Fq,' N'' Thrust on cylinder walls = ',Fn,' N'' speed at which other things remining same,the gudgeon pin load would be reversed in directionm= ',N1,' rpm')\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Net force on piston = 2639.3 N Resultant load on gudgeon pin = 2652.9 N Thrust on cylinder walls = 269.1 N speed at which other things remining same,the gudgeon pin load would be reversed in directionm= 2528.4 rpm \n" ] } ], "prompt_number": 4 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Ex5-pg163" ] }, { "cell_type": "code", "collapsed": false, "input": [ "##CHAPTER 5 ILLUSRTATION 5 PAGE NO 163\n", "##TITLE:Inertia Force Analysis in Machines\n", "##Figure 5.3\n", "import math\n", "pi=3.141\n", "N=1800.## speed of the petrol engine in rpm\n", "r=.06## radius of crank in m\n", "l=.240## length of connecting rod in m\n", "D=.1## diameter of the piston in m\n", "mR=1## mass of piston in kg\n", "p=.8*10**6## gas pressure in N/m**2\n", "x=.012## distance moved by piston in m\n", "##===============================================\n", "w=2.*pi*N/60.## angular velocity of the engine in rad/s\n", "n=l/r\n", "Fl=pi/4.*D**2.*p## load on the piston in N\n", "teeta=32.## by mearument from the figure 5.3\n", "Fi=mR*w**2.*r*(math.cos(teeta/57.3)+math.cos((2*teeta)/57.3)/n)## inertia force due to reciprocating parts in N\n", "Fp=Fl-Fi## net load on the gudgeon pin in N\n", "Fq=n*Fp/((n**2.-(math.sin(teeta/57.3))**2.)**.5)## thrust in the connecting rod in N\n", "Fn=Fp*math.sin(teeta/57.3)/((n**2-(math.sin(teeta/57.3))**2)**.5)## reaction between the piston and cylinder in N\n", "w1=(Fl/mR/r/(math.cos(teeta/57.3)+math.cos((2*teeta)/57.3)/(n)))**.5\n", "N1=60.*w1/(2.*pi)## \n", "print'%s %.1f %s %.1f %s %.1f %s %.1f %s'%('Net load on the gudgeon pin= ',Fp,' N''Thrust in the connecting rod= ',Fq,' N'' Reaction between the cylinder and piston= ',Fn,' N'' The engine speed at which the above values become zero= ',N1,' rpm')\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Net load on the gudgeon pin= 4241.2 NThrust in the connecting rod= 4278.9 N Reaction between the cylinder and piston= 566.8 N The engine speed at which the above values become zero= 3158.0 rpm\n" ] } ], "prompt_number": 5 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Ex6-pg165" ] }, { "cell_type": "code", "collapsed": false, "input": [ "##CHAPTER 5 ILLUSRTATION 6 PAGE NO 165\n", "##TITLE:Inertia Force Analysis in Machines\n", "import math\n", "pi=3.141\n", "D=.25## diameter of horizontal steam engine in m\n", "N=180.## speed of the engine in rpm\n", "d=.05## diameter of piston in m\n", "P=36000.## power of the engine in watts\n", "n=3.## ration of length of connecting rod to the crank radius\n", "p1=5.8*10**5## pressure on cover end side in N/m**2\n", "p2=0.5*10**5## pressure on crank end side in N/m**2\n", "teeta=40.## angle of inclination of crank in degrees\n", "m=45.## mass of flywheel in kg\n", "k=.65## radius of gyration in m\n", "##==============================\n", "Fl=(pi/4.*D**2.*p1)-(pi/4.*(D**2.-d**2.)*p2)## load on the piston in N\n", "ph=(math.sin(teeta/57.3)/n)\n", "phi=math.asin(ph)*57.3## angle of inclination of the connecting rod to the line of stroke in degrees\n", "r=1.6*D/2.\n", "T=Fl*math.sin((teeta+phi)/57.3)/math.cos(phi/57.3)*r## torque exerted on crank shaft in N-m\n", "Fb=Fl*math.cos((teeta+phi)/57.3)/math.cos(phi/57.3)## thrust on the crank shaft bearing in N\n", "TR=P*60./(2.*pi*N)## steady resisting torque in N-m\n", "Ts=T-TR## surplus torque available in N-m\n", "a=Ts/(m*k**2)## acceleration of the flywheel in rad/s**2\n", "print'%s %.1f %s %.1f %s %.1f %s '%('Torque exerted on the crank shaft= ',T,' N-m'' Thrust on the crank shaft bearing= ',Fb,'N''Acceleration of the flywheel= ',a,' rad/s**2')\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Torque exerted on the crank shaft= 4233.8 N-m Thrust on the crank shaft bearing= 16321.0 NAcceleration of the flywheel= 122.2 rad/s**2 \n" ] } ], "prompt_number": 6 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Ex7-pg166" ] }, { "cell_type": "code", "collapsed": false, "input": [ "##CHAPTER 5 ILLUSRTATION 7 PAGE NO 166\n", "##TITLE:Inertia Force Analysis in Machines\n", "import math\n", "pi=3.141\n", "D=.25## diameter of vertical cylinder of steam engine in m\n", "L=.45## stroke length in m\n", "r=L/2.\n", "n=4.\n", "N=360.## speed of the engine in rpm\n", "teeta=45.## angle of inclination of crank in degrees\n", "p=1050000.## net pressure in N/m**2\n", "mR=180.## mass of reciprocating parts in kg\n", "g=9.81## acceleration due to gravity\n", "##========================\n", "Fl=p*pi*D**2./4.## force on piston due to steam pressure in N\n", "w=2.*pi*N/60.## angular speed in rad/s\n", "Fi=mR*w**2.*r*(math.cos(teeta/57.3)+math.cos((2*teeta)/57.3)/(n))## inertia force due to reciprocating parts in N\n", "Fp=Fl-Fi+mR*g## piston effort in N\n", "phi=math.asin((math.sin(teeta/57.3)/n))*57.3## angle of inclination of the connecting rod to the line of stroke in degrees\n", "T=Fp*math.sin((teeta+phi)/57.3)/math.cos(phi/57.3)*r## torque exerted on crank shaft in N-m\n", "print'%s %.1f %s'%('Effective turning moment on the crank shaft= ',T,' N-m')\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Effective turning moment on the crank shaft= 2366.2 N-m\n" ] } ], "prompt_number": 7 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Ex8-pg166" ] }, { "cell_type": "code", "collapsed": false, "input": [ "##CHAPTER 5 ILLUSRTATION 8 PAGE NO 166\n", "##TITLE:Inertia Force Analysis in Machines\n", "##figure 5.4\n", "import math\n", "pi=3.141\n", "D=.25## diameter of vertical cylinder of diesel engine in m\n", "L=.40## stroke length in m\n", "r=L/2.\n", "n=4.\n", "N=300.## speed of the engine in rpm\n", "teeta=60.## angle of inclination of crank in degrees\n", "mR=200.## mass of reciprocating parts in kg\n", "g=9.81## acceleration due to gravity\n", "l=.8## length of connecting rod in m\n", "c=14.## compression ratio=v1/v2\n", "p1=.1*10**6.## suction pressure in n/m**2\n", "i=1.35## index of the law of expansion and compression \n", "##==============================================================\n", "Vs=pi/4.*D**2.*L## swept volume in m**3\n", "w=2.*pi*N/60.## angular speed in rad/s\n", "Vc=Vs/(c-1.)\n", "V3=Vc+Vs/10.## volume at the end of injection of fuel in m**3\n", "p2=p1*c**i## final pressure in N/m**2\n", "p3=p2## from figure\n", "x=r*((1.-math.cos(teeta/57.3)+(math.sin(teeta/57.3))**2/(2.*n)))## the displacement of the piston when the crank makes an angle 60 degrees with T.D.C\n", "Va=Vc+pi*D**2.*x/4.\n", "pa=p3*(V3/Va)**i\n", "p=pa-p1## difference of pressues on 2 sides of piston in N/m**2\n", "Fl=p*pi*D**2./4.## net load on piston in N\n", "Fi=mR*w**2.*r*(math.cos(teeta/57.3)+math.cos(2.*teeta/57.3)/(n))## inertia force due to reciprocating parts in N\n", "Fp=Fl-Fi+mR*g## piston effort in N\n", "phi=math.asin((math.sin(teeta/57.3)/n))*57.3## angle of inclination of the connecting rod to the line of stroke in degrees\n", "T=Fp*math.sin((teeta+phi)/57.3)/math.cos(phi/57.3)*r## torque exerted on crank shaft in N-m\n", "print'%s %.1f %s'%('Effective turning moment on the crank shaft= ',T,' N-m')\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Effective turning moment on the crank shaft= 8850.3 N-m\n" ] } ], "prompt_number": 8 } ], "metadata": {} } ] }