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|
{
"metadata": {
"name": "",
"signature": "sha256:f62e01247c5e7505c14dabc00585a7fb2179310320c1005e1a7d9854022a73b1"
},
"nbformat": 3,
"nbformat_minor": 0,
"worksheets": [
{
"cells": [
{
"cell_type": "heading",
"level": 1,
"metadata": {},
"source": [
"Chapter 15 : Fuel Injection"
]
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Example 15.1 Page no : 274"
]
},
{
"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\t#Number of cylinders\n",
"p = 720.\t\t\t\t\t#Horse power in h.p\n",
"N = 180.\t\t\t\t\t#Speed in r.p.m\n",
"f = 250.\t\t\t\t\t#Fuel rate in gm per horse power hour\n",
"\n",
"\t\t\t\t\t\n",
"#Calculations\n",
"w = (((f/1000)*p)/((N/2)*60*n))*1000\t\t\t\t\t#Weight of fuel per cycle in gm/cycle\n",
"\n",
"\t\t\t\t\t#Outptut\n",
"print 'The quantity of fuel to be injected per cylinder is %3.2f gm/cycle'%(w)\n"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"The quantity of fuel to be injected per cylinder is 5.56 gm/cycle\n"
]
}
],
"prompt_number": 1
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Example 15.2 Page no : 278"
]
},
{
"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",
"fc = 0.215\t\t\t\t\t#Brake specific fuel consumption in kg/B.H.P hour\n",
"BHP = 400\t\t\t\t\t#Brake horse power in B.H.P\n",
"N = 250\t\t\t\t\t#Speed in r.p.m\n",
"sg = 0.9\t\t\t\t\t#Specific gravity\n",
"\n",
"\t\t\t\t\t\n",
"#Calculations\n",
"Fc = (fc*BHP)\t\t\t\t\t#Fuel consumption per hour in kg/hr\n",
"Fcy = (Fc/n)\t\t\t\t\t#Fuel consumption per cylinder in kg/hr\n",
"Fcyc = ((Fcy/(60*(N/2)))/(sg*1000))*10**6\t\t\t\t\t#Fuel consumption per cycle in kg. In textbook it is given wrong as 0.0287 instead of 3.185\n",
"\n",
"\t\t\t\t\t\n",
"#Output\n",
"print 'The quantity of fuel to be injected per cycle per cylinder is %3.3f c.c'%(Fcyc)\n"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"The quantity of fuel to be injected per cycle per cylinder is 3.185 c.c\n"
]
}
],
"prompt_number": 2
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Example 15.3 Page no : 279"
]
},
{
"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",
"p = 450.\t\t\t\t\t#Brake Horse power in B.H.P\n",
"N = 200.\t\t\t\t\t#Speed in r.p.m\n",
"f = 0.2\t\t\t\t\t#Fuel rate in kg per horse power hour\n",
"g = 0.9\t\t\t\t\t#Specific gravity of fuel\n",
"\n",
"\t\t\t\t\t\n",
"#Output\n",
"Fc = (p*f)\t\t\t\t\t#Fuel consumption per hour in kg/hr\n",
"Fcy = (Fc/n)\t\t\t\t\t#Fuel consumption per cylinder in kg/hr\n",
"Fcyc = (Fcy/(60*(N/2)))\t\t\t\t\t#Fuel consumption per cycle in kg\n",
"q = (Fcyc/(g*1000))*10**6\t\t\t\t\t#Quantity of fuel injected per cylinder per cycle in c.c\n",
"\n",
"\t\t\t\t\t\n",
"#Output\n",
"print 'The quantity of fuel to be injected per cycle per cylinder is %3.3f c.c'%(q)\n"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"The quantity of fuel to be injected per cycle per cylinder is 4.167 c.c\n"
]
}
],
"prompt_number": 3
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Example 15.4 Page no : 284"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"import math \n",
"\t\t\t\t\t\n",
"#Input data\n",
"#Data from problem 1\n",
"n = 6.\t\t\t\t\t#Number of cylinders\n",
"p = 720.\t\t\t\t\t#Horse power in h.p\n",
"N = 180.\t\t\t\t\t#Speed in r.p.m\n",
"f = 250.\t\t\t\t\t#Fuel rate in gm per horse power hour\n",
"\n",
"Vo = 20.\t\t\t\t\t#Volume of oil in the suction chamber in c.c\n",
"dp = 80.\t\t\t\t\t#Discharge pressure in kg/cm**2\n",
"voi = 6.\t\t\t\t\t#Volume of oil in the injector in c.c\n",
"g = 0.9\t\t\t\t\t#Specific gravity of oil\n",
"b = 78.8*10**-6\t\t\t\t\t#Coefficient of compressibility in cm**2/kg when pressure is taken as atmospheric\n",
"\n",
"\t\t\t\t\t\n",
"#Calculations\n",
"w = (((f/1000)*p)/((N/2)*60*n))*1000\t\t\t\t\t#Weight of fuel per cycle in gm/cycle\n",
"Va = (w/g)\t\t\t\t\t#Volume of air per cycle in c.c\n",
"V1 = (Vo+Va)\t\t\t\t\t#Initial volume in c.c\n",
"dV12 = (b*V1*dp)\t\t\t\t\t#Change in volume in c.c\n",
"\t\t\t\t\t#Assuming in accordance with average practice that s = 2d, nv = 0.94 and full load in this pump type x = 0.5\n",
"d = ((voi+dV12)/((3.14/4)*2*0.94*0.5))**(1./3)\t\t\t\t\t#Diameter in cm\n",
"l = (2*d)\t\t\t\t\t#Stroke in cm\n",
"\n",
"\t\t\t\t\t\n",
"#Output\n",
"print 'The diameter of the pump is %3.2f cm \\\n",
"\\nThe total stroke is %3.2f cm'%(d,l)\n"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"The diameter of the pump is 2.03 cm \n",
"The total stroke is 4.06 cm\n"
]
}
],
"prompt_number": 4
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Example 15.5 Page no : 287"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"import math \n",
"\t\t\t\t\t\n",
"#Input data\n",
"p = 110.\t\t\t\t\t#Oil pressure in kg/cm**2\n",
"pc = 25.\t\t\t\t\t#Pressure in the combustion chamber in kg/cm**2\n",
"q = 0.805\t\t\t\t\t#Velocity coefficient. In textbook it is given wrong as 9.805\n",
"d = 0.906\t\t\t\t\t#Specific gravity\n",
"\n",
"\t\t\t\t\t\n",
"#Calculations\n",
"v = (37.1*q*math.sqrt((p-pc)/d))\t\t\t\t\t#Velocity in m/s\n",
"\n",
"\t\t\t\t\t\n",
"#Output\n",
"print 'The velocity of injection is %3.0f m/s'%(v)\n"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"The velocity of injection is 289 m/s\n"
]
}
],
"prompt_number": 5
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Example 15.6 Page no : 290"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"import math \n",
"\t\t\t\t\t\n",
"#Input data\n",
"Vf = 6.2\t\t\t\t\t#Volume of fuel in c.c\n",
"l = 65\t\t\t\t\t#Length of fuel line in cm\n",
"di = 2.5\t\t\t\t\t#Inner diameter in mm\n",
"V = 2.75\t\t\t\t\t#Volume of fuel in the injector valve in c.c\n",
"Vd = 0.15\t\t\t\t\t#Volume of fuel to be delivered in c.c. In textbook it is given wrong as 0.047\n",
"p = 140\t\t\t\t\t#Pressure in kg/cm**2\n",
"pp = 1\t\t\t\t\t#Pump pressure in kg/cm**2\n",
"patm = 1.03\t\t\t\t\t#Atmospheric pressure in kg/cm**2\n",
"b = 78.8*10**-6\t\t\t\t\t#Coefficient of compressibility in cm**2/kg when pressure is taken as atmospheric\n",
"\n",
"\t\t\t\t\t\n",
"#Calculations\n",
"V1 = (Vf+(3.14/4)*(di/10)**2*l+V)\t\t\t\t\t#Initial volume in c.c\n",
"dV = ((b*V1*(p-pp)/patm))\t\t\t\t\t#Change in volume in c.c\n",
"d = (dV+Vd)\t\t\t\t\t#Total print lacement of the plunger in c.c\n",
"\n",
"\t\t\t\t\t\n",
"#Output\n",
"print 'The total print lacement of the plunger is %3.3f c.c'%(d)\n"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"The total print lacement of the plunger is 0.279 c.c\n"
]
}
],
"prompt_number": 6
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Example 15.7 Page no : 292"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"import math \n",
"\t\t\t\t\t\n",
"#Input data\n",
"Vf = 6.75\t\t\t\t\t#Volume of fuel in c.c\n",
"l = 65\t\t\t\t\t#Length of fuel line in cm\n",
"di = 2.5\t\t\t\t\t#Inner diameter in mm\n",
"V = 2.45\t\t\t\t\t#Volume of fuel in the injector valve in c.c\n",
"Vd = 0.15\t\t\t\t\t#Volume of fuel to be delivered in c.c. \n",
"p = 150\t\t\t\t\t#Pressure in kg/cm**2\n",
"pp = 1\t\t\t\t\t#Pump pressure in kg/cm**2\n",
"patm = 1.03\t\t\t\t\t#Atmospheric pressure in kg/cm**2\n",
"b = 78.8*10**-6\t\t\t\t\t#Coefficient of compressibility in cm**2/kg when pressure is taken as atmospheric\n",
"\n",
"\t\t\t\t\t\n",
"#Calculations\n",
"V1 = (Vf+(3.14/4)*(di/10)**2*l+V)\t\t\t\t\t#Initial volume in c.c\n",
"dV = ((b*V1*(p-pp)/patm))\t\t\t\t\t#Change in volume in c.c\n",
"d = (dV+Vd)\t\t\t\t\t#Total print lacement of the plunger in c.c\n",
"\n",
"\t\t\t\t\t\n",
"#Output\n",
"print 'The total print lacement of the plunger is %3.3f c.c'%(d)\n"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"The total print lacement of the plunger is 0.291 c.c\n"
]
}
],
"prompt_number": 7
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Example 15.8 Page no : 295"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"import math \n",
"\t\t\t\t\t\n",
"#Input data\n",
"Vf = 6.75\t\t\t\t\t#Volume of fuel in c.c\n",
"l = 65\t\t\t\t\t#Length of fuel line in cm\n",
"di = 2.5\t\t\t\t\t#Inner diameter in mm\n",
"V = 2.45\t\t\t\t\t#Volume of fuel in the injector valve in c.c\n",
"Vd = 0.15\t\t\t\t\t#Volume of fuel to be delivered in c.c. \n",
"p = 150\t\t\t\t\t#Pressure in kg/cm**2\n",
"pp = 1\t\t\t\t\t#Pump pressure in kg/cm**2\n",
"patm = 1.03\t\t\t\t\t#Atmospheric pressure in kg/cm**2\n",
"b = 78.8*10**-6\t\t\t\t\t#Coefficient of compressibility in cm**2/kg when pressure is taken as atmospheric\n",
"dp = 0.75\t\t\t\t\t#Diameter of the plunger in cm\n",
"\n",
"\t\t\t\t\t\n",
"#Calculations\n",
"V1 = (Vf+(3.14/4)*(di/10)**2*l+V)\t\t\t\t\t#Initial volume in c.c\n",
"dV = ((b*V1*(p-pp)/patm))\t\t\t\t\t#Change in volume in c.c\n",
"d = (dV+Vd)\t\t\t\t\t#Total print lacement of the plunger in c.c\n",
"s = ((4/3.14)*(d/dp**2))*10\t\t\t\t\t#Stroke in mm\n",
"\n",
"\t\t\t\t\t\n",
"#Output\n",
"print 'The effective plunger stroke is %3.1f mm'%(s)\n"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"The effective plunger stroke is 6.6 mm\n"
]
}
],
"prompt_number": 8
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Example 15.9 Page no : 298"
]
},
{
"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",
"p = 300.\t\t\t\t\t#Horse power in H.P\n",
"N = 1200.\t\t\t\t\t#Speed in r.p.m\n",
"f = 0.2\t\t\t\t\t#Fuel rate in kg per B.H.P hour\n",
"ip = 200.\t\t\t\t\t#Injection pressure in kg/cm**2\n",
"cp = 40.\t\t\t\t\t#Pressure in the combustion chamber in kg/cm**2\n",
"pic = 33.\t\t\t\t\t#Period of injection of the crank angle in degrees\n",
"g = 0.83\t\t\t\t\t#Specific gravity of fuel. In textbook, it is given wrong as 0.89\n",
"Cd = 0.9\t\t\t\t\t#Coefficient of discharge \n",
"\n",
"\t\t\t\t\t\n",
"#Output\n",
"Fc = (p*f)\t\t\t\t\t#Fuel consumption per hour in kg/hr\n",
"Fcy = (Fc/n)\t\t\t\t\t#Fuel consumption per cylinder in kg/hr\n",
"Fcyc = (Fcy/(60*(N/2)))\t\t\t\t\t#Fuel consumption per cycle in kg\n",
"q = (Fcyc/(g*1000))*10**6\t\t\t\t\t#Quantity of fuel injected per cylinder per cycle in c.c\n",
"I = ((pic/360.)*(1/N)*60)\t\t\t\t\t#Injection period in sec\n",
"df = (g/1000)\t\t\t\t\t#Density of fuel in kg/m**3\n",
"v = math.sqrt(2*981*((ip-cp)/df))\t\t\t\t\t#Velocity of fuel through orifice in m/s\n",
"A = (q/(Cd*v*I))\t\t\t\t\t#Area of orifice in cm**2\n",
"d = math.sqrt(A/(3.14/4))*10\t\t\t\t\t#Diameter in mm\n",
"\n",
"\t\t\t\t\t\n",
"#Output\n",
"print 'The diameter of the math.single orifice injector is %3.2f mm'%(d)\n"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"The diameter of the math.single orifice injector is 0.73 mm\n"
]
}
],
"prompt_number": 10
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Example 15.10 Page no : 302"
]
},
{
"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 = 11.5\t\t\t\t\t#Bore in cm\n",
"l = 14\t\t\t\t\t#Stroke in cm\n",
"af = 16\t\t\t\t\t#Air fuel ratio\n",
"pa = 1.03\t\t\t\t\t#Pressure of air intake in kg/cm**2\n",
"Ta = 24+273\t\t\t\t\t#Temperature of air intake in K\n",
"nv = 76.5\t\t\t\t\t#Volumetric efficiency in percent\n",
"R = 29.27\t\t\t\t\t#Characteristic gas constant in kg.m/kg.K\n",
"N = 1500\t\t\t\t\t#Speed in r.p.m\n",
"ip = 125\t\t\t\t\t#Injection pressure in kg/cm**2\n",
"cp = 40\t\t\t\t\t#Compression pressure in kg/cm**2\n",
"q = 18.5\t\t\t\t\t#Fuel injection occupies 18.5 degrees of crenk travel\n",
"fsw = 760\t\t\t\t\t#Fuel specific weight in kg/m**2\n",
"dc = 0.94\t\t\t\t\t#Orifice discharge coefficient\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\n",
"Va = (Vs*(nv/100))\t\t\t\t\t#Volume of air supplied in c.c\n",
"wa = ((pa*10**4*Va*10**-6)/(R*Ta))\t\t\t\t\t#Weight of air supplied per cylinder per cycle in kg\n",
"wf = (wa/af)\t\t\t\t\t#Weight of fuel injected per cylinder per cycle in kg\n",
"I = ((60*q)/(N*360))\t\t\t\t\t#Injection time per cycle in sec\n",
"F = (wf/I)\t\t\t\t\t#Fuel injected per cylinder per sec in kg/sec\n",
"Af = (F/(dc*math.sqrt(2*9.81*fsw*(ip-cp)*10**4)))\t\t\t\t\t#Area of orifice in sq.m\n",
"df = math.sqrt(Af/(3.14/4))*1000\t\t\t\t\t#Diameter of orifice in mm\n",
"\n",
"\t\t\t\t\t\n",
"#Output\n",
"print 'Maximum amount of fuel injected per cylinder per sec is %3.2f kg/sec \\\n",
"\\nDiameter of orifice is %3.3f mm'%(F,df)\n"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"Maximum amount of fuel injected per cylinder per sec is 0.04 kg/sec \n",
"Diameter of orifice is 0.694 mm\n"
]
}
],
"prompt_number": 11
}
],
"metadata": {}
}
]
}
|
