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{
"metadata": {
"name": "",
"signature": "sha256:e5ce604b49bc138fd65826c495598b13c742523cc595beeb292a2a1aa22f7c49"
},
"nbformat": 3,
"nbformat_minor": 0,
"worksheets": [
{
"cells": [
{
"cell_type": "heading",
"level": 1,
"metadata": {},
"source": [
"Chapter3-Engine Thrust and Performance Parameters"
]
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Ex1-pg101"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"import math\n",
"#calculate The ram drag for given engine in kN\n",
"M0=0.85 ##Mach no.\n",
"a0=300. ##speed of sound in m/s\n",
"m=50. ##Air mass flow rate in kg/s\n",
"##Calculations\n",
"V0=M0*a0 ##Flight speed\n",
"Dr=m*V0 ##Ram drag\n",
"Dk=Dr/1000. ##in kN\n",
"print'%s %.2f %s'%(\"The ram drag for given engine in kN:\",Dk,\"\")"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"The ram drag for given engine in kN: 12.75 \n"
]
}
],
"prompt_number": 1
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Ex2-pg102"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"#calculate gross thurst of the core and fan nozzles\n",
"\n",
"Cv=450. ##exhaust velocity at core in m/s\n",
"Nv=350. ##exhaust velocity at nozzle in m/s\n",
"Cm=50. ##Mass flow rate through core in kg/s\n",
"Nm=350. ##Mass flow rate through nozzle in kg/s\n",
"##Calculations:\n",
"##Newton's second law\n",
"Fgc=Cm*Cv ##gross thrust of the core\n",
"Fgf=Nm*Nv ##gross thrust of the nozzle fan\n",
"print'%s %.f %s'%(\"Gross thrust of the core in\",Fgc,\"N\")\n",
"print'%s %.f %s'%(\"Gross thrust of the fan nozzles in\",Fgf,\"N\")\n"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"Gross thrust of the core in 22500 N\n",
"Gross thrust of the fan nozzles in 122500 N\n"
]
}
],
"prompt_number": 3
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Ex3-pg111"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"import math\n",
"#calculate The rocket gross thrust and pressure thurst\n",
"V9=4000 ##in m/s\n",
"p9=200*10**3 ##in Pa\n",
"p0=100*10**3 ## in Pa\n",
"D=2. ##in meter\n",
"m=200.+50. ## in kg/s\n",
"A=math.pi*(D**2)/4. ##nozzle exit area\n",
"##let p=(p9-p0)*A i.e. pressure thrust\n",
"p=(p9-p0)*A\n",
"mt=m*V9 ##momentum thrust.\n",
"t=p+mt ##rocket gross thrust\n",
"print'%s %.2f %s'%(\"The pressure thrust in\",p,\"N\")\n",
"print'%s %.1f %s'%(\"The rocket gross thrust in\",t,\"N\")"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"The pressure thrust in 314159.27 N\n",
"The rocket gross thrust in 1314159.3 N\n"
]
}
],
"prompt_number": 5
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Ex4-pg114"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"import math\n",
"#calcualte engine thurst takeoff\n",
"m0=100. ##air flow rate in kg/s\n",
"V0=0. ##takeoff assumptions in m/s\n",
"mf=2. ##2% of fuel-to-air ratio\n",
"Qr=43000. ##Heating value of typical hydrocarbon fuel in kJ/kg\n",
"V9=900. ##high speed exhaust jet (in m/s)\n",
"e=((m0+mf)*(V9)**2.)/(2.*(mf)*(Qr)*1000.)\n",
"m9=m0+mf\n",
"t=m9*V9 ## the engine thrust at takeoff.\n",
"print'%s %.f %s'%(\"The engine thrust at takeoff in SI units\",t,\"N\")"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"The engine thrust at takeoff in SI units 91800 N\n"
]
}
],
"prompt_number": 7
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Ex5-pg117"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"#calculate the Engine propulsive efficiency\n",
"V9=900. ## in m/s\n",
"V0=200. ## in m/s\n",
"e=2./(1.+(V9/V0))\n",
"print'%s %.7f %s'%(\"Engine propulsive efficiency\",e,\"\")"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"Engine propulsive efficiency 0.3636364 \n"
]
}
],
"prompt_number": 9
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Ex6-pg118"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"#estimate Propulsive efficiency\n",
"import math\n",
"V9=250. ##in m/s\n",
"V0=200. ##in m/s\n",
"##Calculations:\n",
"e=2./(1.+(V9/V0))\n",
"print'%s %.3f %s'%(\"Propulsive efficiency:\",e,\"\")"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"Propulsive efficiency: 0.889 \n"
]
}
],
"prompt_number": 8
}
],
"metadata": {}
}
]
}
|
