{ "metadata": { "name": "", "signature": "sha256:0ee42d9d2a59bb1cfbe70f62b85f016177a8e60e52a35949d0f6ab86ccafc621" }, "nbformat": 3, "nbformat_minor": 0, "worksheets": [ { "cells": [ { "cell_type": "heading", "level": 1, "metadata": {}, "source": [ "Chapter 8 : Two Marks Questions and Answers" ] }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 8.34 page : 8" ] }, { "cell_type": "code", "collapsed": false, "input": [ "import math \n", "\n", "\t\t\t\t\n", "#Input data\n", "C = 500. \t\t\t\t#Airplane velocity in m/s\n", "T = 20.+273 \t\t\t\t#Temperature in K\n", "k = 1.4 \t\t\t\t#Adiabatic consmath.tant \n", "R = 287 \t\t\t\t#Specific gas consmath.tant in J/kg-K\n", "\n", "\t\t\t\t\n", "#Calculation\n", "a = math.sqrt(k*R*T) \t\t\t\t#Sound velocity in m/s\n", "M = C/a \t\t\t\t#Mach number\n", "alp = math.degrees(math.asin((1/M))) \t\t\t\t#Mach angle in degree\n", "\n", "\t\t\t\t\n", "#Output\n", "print 'Mach angle is %3.3f degree'%(alp)\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Mach angle is 43.332 degree\n" ] } ], "prompt_number": 7 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 8.35 page : 8" ] }, { "cell_type": "code", "collapsed": false, "input": [ "import math \n", "\n", "\t\t\t\t\n", "#Input data\n", "a1 = 2.2 \t\t\t\t#Area ratio (A/At)\n", "Po = 10 \t\t\t\t#Stagnation Pressure in bar\n", "\n", "\t\t\t\t\n", "#Calculation\n", "\t\t\t\t#Two values of mach number at a1 from gas tables\n", "\n", "M1 = 0.275 \t\t\t\t#Mach number from gas tables\n", "p1 = 0.949 \t\t\t\t#Presure ratio (P/Po)\n", "P1 = Po*p1 \t\t\t\t#back pressure in bar\n", "\n", "M2 = 2.295 \t\t\t\t#Mach number from gas tables\n", "p2 = 0.0806 \t\t\t\t#Presure ratio (P/Po)\n", "P2 = Po*p2 \t\t\t\t#back pressure in bar\n", "\n", "\t\t\t\t\n", "#Output\n", "print 'A)When M = %3.3f, back pressure is %3.2f bar \\\n", "\\nB)When M = %3.3f, back pressure is %3.3f bar'%(M1,P1,M2,P2)\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "A)When M = 0.275, back pressure is 9.49 bar \n", "B)When M = 2.295, back pressure is 0.806 bar\n" ] } ], "prompt_number": 8 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 8.37 page : 9" ] }, { "cell_type": "code", "collapsed": false, "input": [ "import math \n", "\n", "\t\t\t\t\n", "#Input data\n", "M = 0.8 \t\t\t\t#Mach number\n", "T = 20+273 \t\t\t\t#Temperature in K\n", "k = 1.4 \t\t\t\t#Adiabatic consmath.tant \n", "\n", "\t\t\t\t\n", "#Calculation \n", "To = T*(1+(((k-1)/2)*M**2)) \t\t\t\t#Temperature of air at nose of aircraft in K\n", "To1 = To-273 \t\t\t\t#Temperature of air at nose of aircraft in degree Centigrade\n", "\n", "\t\t\t\t\n", "#Output \n", "print 'Temperature of air at nose of aircraft is %3.1f degree Centigrade'%(To1)\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Temperature of air at nose of aircraft is 57.5 degree Centigrade\n" ] } ], "prompt_number": 9 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 8.38 page 9" ] }, { "cell_type": "code", "collapsed": false, "input": [ "import math \n", "\n", "\t\t\t\t\n", "#Input data\n", "P = 1. \t\t\t\t#Pressure in bar\n", "T = 400. \t\t\t\t#Temperature in K\n", "C = 400. \t\t\t\t#Air velocity in m/s\n", "k = 1.4 \t\t\t\t#Adiabatic consmath.tant \n", "R = 287. \t\t\t\t#Specific gas consmath.tant in J/kg-K\n", "Cp = 1005. \t\t\t\t#Specific heat capacity at constnat pressure in J/kg-K\n", "\n", "\t\t\t\t\n", "#Calculation\n", "To = T+(C**2/(2*Cp)) \t\t\t\t#Stagnation Temperature in K\n", "Poi = P+((P*C**2)/(R*T*2)) \t\t\t\t#Stagnation Pressure (if it is incompressible) in bar\n", "Poc = P*(To/T)**(k/(k-1)) \t\t\t\t#Stagnation Pressure (if it is compressible) in bar\n", "\n", "\t\t\t\t\n", "#Output\n", "print 'Stagnation Temperature is %3.1f K \\\n", "\\nC)Stagnation Pressure: \\\n", "\\nIf it is incompressible is %3.4f bar \\\n", "\\nIf it is compressible is %3.4f bar'%(To,Poi,Poc)\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Stagnation Temperature is 479.6 K \n", "C)Stagnation Pressure: \n", "If it is incompressible is 1.6969 bar \n", "If it is compressible is 1.8874 bar\n" ] } ], "prompt_number": 11 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 8.39 page : 9" ] }, { "cell_type": "code", "collapsed": false, "input": [ "import math \n", "\n", "\t\t\t\t\n", "#Input data\n", "v1 = 8 \t\t\t\t#Intial volume in litres\n", "P1 = 0.7 \t\t\t\t#Intial pressure in MPa\n", "v2 = 7.8 \t\t\t\t#Final volume in litres\n", "P2 = 2.7 \t\t\t\t#Final pressure in MPa\n", "\n", "\t\t\t\t\n", "#Calculation\n", "k = (P2-P1)/(math.log(v1/v2)) \t\t\t\t#Bulk modulus of elasticity of a liquid in MPa\n", "\n", "\t\t\t\t\n", "#Output\n", "print 'Bulk modulus of elasticity of a liquid is %3.3f MPa'%k\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Bulk modulus of elasticity of a liquid is 78.996 MPa\n" ] } ], "prompt_number": 12 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 8.40 page : 9" ] }, { "cell_type": "code", "collapsed": false, "input": [ "import math \n", "\n", "\t\t\t\t\n", "#Input data\n", "To = 15+273 \t\t\t\t#Air Temperature in K\n", "Cp = 1005 \t\t\t\t#Specific heat capacity at constnat pressure in J/kg-K\n", "\n", "\t\t\t\t\n", "#Calculation \n", "Cmax = math.sqrt(2*Cp*To) \t\t\t\t#Highest possible velocity in m/s\n", "\n", "\t\t\t\t\n", "#Output\n", "print 'Highest possible velocity is %3.2f m/s'%Cmax\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Highest possible velocity is 760.84 m/s\n" ] } ], "prompt_number": 13 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 8.3.10 page : 12" ] }, { "cell_type": "code", "collapsed": false, "input": [ "import math \n", "\n", "\t\t\t\t\n", "#Input data\n", "M = 0.25 \t\t\t\t#mach number\n", "D = 0.04 \t\t\t\t#Diamter in m\n", "f = 0.002 \t\t\t\t#frictional factor\n", "\n", "\t\t\t\t\n", "#Calculation\n", "X = 8.483 \t\t\t\t#fanno parameter from gas tables at M\n", "Lmax = (X*D)/(4*f) \t\t\t\t#Lenggth of the pipe in m\n", "\n", "\t\t\t\t\n", "#Output\n", "print 'Length of the pipe is %3.3f m'%Lmax\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Length of the pipe is 42.415 m\n" ] } ], "prompt_number": 7 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 8.3.15 page : 13" ] }, { "cell_type": "code", "collapsed": false, "input": [ "import math \n", "\n", "\t\t\t\t\n", "#Input data\n", "M = 3. \t\t\t\t#mach number\n", "D = 0.04 \t\t\t\t#Diamter in m\n", "f = 0.002 \t\t\t\t#frictional factor\n", "\n", "\t\t\t\t\n", "#Calculation\n", "X = 0.522 \t\t\t\t#fanno parameter from gas tables at M\n", "L = (X*D)/(4*f) \t\t\t\t#Lenggth of the pipe in m\n", "\n", "\t\t\t\t\n", "#Output\n", "print 'Lenggth of the pipe is %3.2f m'%L\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Lenggth of the pipe is 2.61 m\n" ] } ], "prompt_number": 14 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 8.3.31 page : 16" ] }, { "cell_type": "code", "collapsed": false, "input": [ "import math \n", "\n", "\t\t\t\t\n", "#Input data\n", "M = 0.2 \t\t\t\t#Mach number\n", "To = 120.+273 \t\t\t\t#Stagnation Temperature in K\n", "Cp = 1005. \t\t\t\t#Specific heat capacity at constnat pressure in J/kg-K\n", "\n", "\t\t\t\t\n", "#Calculation\n", "t1 = 0.174 \t\t\t\t#Temperature ratio (To/Tot) from Rayleigh gas tables\n", "Tot = To/t1 \t\t\t\t#Critical stagnation temperature in K\n", "q = Cp*(Tot-To)*10**-3 \t\t\t\t#Maximum amount of heat transfer in kJ/kg\n", "\n", "\t\t\t\t\n", "#Output\n", "print 'Maximum amount of heat transfer is %3.2f kJ/kg'%q\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Maximum amount of heat transfer is 1874.95 kJ/kg\n" ] } ], "prompt_number": 15 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 8.3.32 page : 17" ] }, { "cell_type": "code", "collapsed": false, "input": [ "import math \n", "\n", "\t\t\t\t\n", "#Input data\n", "p1 = 0.75 \t\t\t\t#Pressure ratio (Po2/Po1) Since Stagnation pressure drop is 25%\n", "Cp = 1150. \t\t\t\t#Specific heat capacity at constnat pressure in J/kg-K\n", "k = 1.33 \t\t\t\t#Adiabatic consmath.tant \n", "\n", "\t\t\t\t\n", "#Calculation\n", "ds = ((k-1)/k)*Cp*math.log(1/p1) \t\t\t\t#Increase in entropy in J/kg-K\n", "\n", "\t\t\t\t\n", "#Output \n", "print 'Increase in entropy is %3.2f J/kg-K'%ds\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Increase in entropy is 82.09 J/kg-K\n" ] } ], "prompt_number": 16 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 8.3.33 page : 17" ] }, { "cell_type": "code", "collapsed": false, "input": [ "import math \n", "\n", "\t\t\t\t\n", "#Input data\n", "Mi = 2.2 \t\t\t\t#Inlet Mach number\n", "T = 100.+273 \t\t\t\t#Temperature in K\n", "Cp = 1005. \t\t\t\t#Specific heat capacity at constnat pressure in J/kg-K\n", "\n", "\t\t\t\t\n", "#Calculation\n", "t1 = 0.508 \t\t\t\t#Temperature ratio (To/Tot) from isentropic gas tables @Mi\n", "To = T/t1 \t\t\t\t#Stagnation Temperature in K\n", "t2 = 0.756 \t\t\t\t#Temperature ratio (To/Tot) from Rayleigh gas tables @Mi\n", "Tot = To/t2 \t\t\t\t#Critical stagnation temperature in K\n", "q = Cp*(Tot-To)*10**-3 \t\t\t\t#Maximum amount of heat transfer in kJ/kg\n", "\n", "\t\t\t\t\n", "#Output\n", "print 'Maximum amount of heat transfer is %3.4f kJ/kg'%q\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Maximum amount of heat transfer is 238.1657 kJ/kg\n" ] } ], "prompt_number": 17 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 8.5.16 page: 22" ] }, { "cell_type": "code", "collapsed": false, "input": [ "import math \n", "\n", "\t\t\t\t\n", "#Input data\n", "Mx = 1.5 \t\t\t\t#Mach number\n", "P = 40. \t\t\t\t#Static pressure in kPa\n", "\n", "\t\t\t\t\n", "#Calculation\n", "p1 = 3.413 \t\t\t\t#Pressure ratio in (Poy/Px) from normal shock gas tables @Mx\n", "Poy = p1*P \t\t\t\t#Pressure acting on front of the body in kPa\n", "\n", "\t\t\t\t\n", "#Output\n", "print 'Pressure acting on front of the body is %3.1f kPa'%Poy\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Pressure acting on front of the body is 136.5 kPa\n" ] } ], "prompt_number": 18 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 8.5.17 page : 22" ] }, { "cell_type": "code", "collapsed": false, "input": [ "import math \n", "\n", "\t\t\t\t\n", "#Input data\n", "M = 2. \t\t\t\t#Mach number at shock\n", "\n", "\t\t\t\t\n", "#Calculation\n", "p1 = 4.5 \t\t\t\t#Pressure ratio (Py/Px) from normal shock gas tables @M\n", "e = p1-1 \t\t\t\t#Strength of shock wave\n", "\n", "\t\t\t\t\n", "#Output\n", "print 'Strength of shock wave is %3.1f'%e\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Strength of shock wave is 3.5\n" ] } ], "prompt_number": 19 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 8.5.20 page : 23" ] }, { "cell_type": "code", "collapsed": false, "input": [ "import math \n", "\n", "\t\t\t\t\n", "#Input data\n", "Mx = 7 \t\t\t\t#mach number upstream of shock\n", "P = 2 \t\t\t\t#pressure @Mx in bar\n", "T = 57+273 \t\t\t\t#Temperature @Mx in K\n", "R = 287 \t\t\t\t#Specific gas consmath.tant in J/kg-K\n", "\n", "\t\t\t\t\n", "#Calculation \n", "p1 = 0.72 \t\t\t\t#Pressure ratio (Poy/Pox) from normal shock gas tables @Mx\n", "ds = R*math.log(1/p1) \t\t\t\t#Irreversibility in J/kg-K\n", "\n", "\t\t\t\t\n", "#Output\n", "print 'Irreversibility is %3.2f J/kg-K'%ds\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Irreversibility is 94.28 J/kg-K\n" ] } ], "prompt_number": 20 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ " Example 8.5.21 page : 23" ] }, { "cell_type": "code", "collapsed": false, "input": [ "import math \n", "\n", "\t\t\t\t\n", "#Input data\n", "Px = 45. \t\t\t\t#Static pressure in kPa\n", "T = -20.+273 \t\t\t\t#Static temperature in K\n", "Poy = 395. \t\t\t\t#Stagnation pressure in kPa\n", "k = 1.4 \t\t\t\t#Adiabatic consmath.tant \n", "R = 287 \t\t\t\t#Specific gas consmath.tant in J/kg-K\n", "\n", "\t\t\t\t\n", "#Calculation\n", "p1 = Poy/Px \t\t\t\t#Pressure ratio\n", "Mx = 2.536 \t\t\t\t#Mach number from normal shock gas tables @p1\n", "Cx = Mx*math.sqrt(k*R*T) \t\t\t\t#Air velocity in m/s\n", "\n", "\t\t\t\t\n", "#Output\n", "print 'Mach number is %3.3f \\\n", "\\nAir velocity is %.f m/s'%(Mx,Cx)\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Mach number is 2.536 \n", "Air velocity is 809 m/s\n" ] } ], "prompt_number": 21 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 8.5.22 page : 23" ] }, { "cell_type": "code", "collapsed": false, "input": [ "import math \n", "\n", "\t\t\t\t\n", "#Input data\n", "Cx = 750. \t\t\t\t#velocity upstream of shock in m/s\n", "Px = 1. \t\t\t\t#Pressure upstream of shock in bar\n", "Tx = 10.+273 \t\t\t\t#Temperature upstream of shock in K\n", "k = 1.4 \t\t\t\t#Adiabatic consmath.tant \n", "R = 287. \t\t\t\t#Specific gas consmath.tant in J/kg-K\n", "\n", "\t\t\t\t\n", "#Calculation\n", "Mx = Cx/math.sqrt(k*R*Tx) \t\t\t\t#Mach number upstream of shock\n", "My = 0.545 \t\t\t\t#Mach number downstream of shock from normal shock gas tables, Mistake in textbook\n", "t1 = 1.875 \t\t\t\t#Temperature ratio (Ty/Tx)\n", "Ty = Tx*t1 \t\t\t\t#Static temperature downstream of shock in K\n", "p1 = 5.583 \t\t\t\t#Pressure ratio (Py/Px)\n", "Py = Px*p1 \t\t\t\t#Static pressure downstream of shock in bar\n", "Cy = My*math.sqrt(k*R*Ty) \t\t\t\t#velocity downstream of shock in m/s\n", "\n", "\t\t\t\t\n", "#Output\n", "print 'Downstream of shock: Velocity is %3.3f m/s Pressure is %3.3f bar Temperature is %3.3f K'%(Cy,Py,Ty)\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Downstream of shock: Velocity is 251.649 m/s Pressure is 5.583 bar Temperature is 530.625 K\n" ] } ], "prompt_number": 22 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 8.6.41 page : 31" ] }, { "cell_type": "code", "collapsed": false, "input": [ "import math \n", "\n", "\t\t\t\t\n", "#Calculation \n", "\n", "#Differentiating P = m*(Cj-u)*u and equating it to zero we get jet speed ratio as 0.5\n", "sig = 0.5 \t\t\t\t#Jet speed ratio \n", "eff_max = ((2*sig)/(1+sig)) \t\t\t\t#Propulsive efficiency for optimum thrust power, wrong notation in textbook.\n", "\n", "\t\t\t\t\n", "#Output\n", "print 'Propulsive efficiency for optimum thrust power is %3.3f'%(eff_max)\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Propulsive efficiency for optimum thrust power is 0.667\n" ] } ], "prompt_number": 23 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 8.6.42 page : 31" ] }, { "cell_type": "code", "collapsed": false, "input": [ "import math \n", "\n", "#Input data\n", "u = 1200*(5./18) \t\t\t\t#Flight velocity in m/s\n", "Cj = 800. \t\t\t\t#Effective jet velocity in m/s\n", "\n", "\t\t\t\t\n", "#Calculation\n", "sig = u/Cj \t\t\t\t#jet speed ratio\n", "eff = ((2*sig)/(1+sig))*100 \t\t\t\t#Propulsive efficiency in %\n", "\n", "\t\t\t\t\n", "#Output\n", "print 'Propulsive efficiency is %3.1f percent'%eff\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Propulsive efficiency is 58.8 percent\n" ] } ], "prompt_number": 24 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 8.7.42 page : 39" ] }, { "cell_type": "code", "collapsed": false, "input": [ "import math \n", "\n", "\t\t\t\t\n", "#Input data\n", "m = 5. \t\t\t\t#Propellent rate in kg/s\n", "Pamb = 1.013 \t\t\t\t#Ambient pressure in bar\n", "Pe = 1.02 \t\t\t\t#Nozzle exit pressure in bar\n", "D = 0.1 \t\t\t\t#Nozzle exit diameter in m\n", "Ce = 1400. \t\t\t\t#Exit jet velocity in m/s\n", "\n", "\t\t\t\t\n", "#Calculation\n", "Ae = math.pi*D**2/4 \t\t\t\t#Exit area in m**2\n", "F = (m*Ce)+((Pe-Pamb)*Ae) \t\t\t\t#Thrust in N\n", "\n", "\t\t\t\t\n", "#Output\n", "print 'Thrust is %3i N'%F\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Thrust is 7000 N\n" ] } ], "prompt_number": 25 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 8.7.43 page : 39" ] }, { "cell_type": "code", "collapsed": false, "input": [ "import math \n", "\n", "\t\t\t\t\n", "#Input data\n", "Is = 230. \t\t\t\t#Specific Impulse in sec\n", "m = 1. \t\t\t\t#Propellent flow in kg/s\n", "g = 9.81 \t\t\t\t#Acceleration due to gravity in m/s**2\n", "\n", "\t\t\t\t\n", "#Calculation\n", "F = m*Is*g \t\t\t\t#Thrust in N\n", "\n", "\t\t\t\t\n", "#Output\n", "print 'Thrust is %3.1f N'%F\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Thrust is 2256.3 N\n" ] } ], "prompt_number": 26 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 8.7.45 page : 39" ] }, { "cell_type": "code", "collapsed": false, "input": [ "import math \n", "\n", "\t\t\t\t\n", "#Input data\n", "u = 1500. \t\t\t\t#Flight velocity in m/s\n", "eff = 0.75 \t\t\t\t#Propulsive efficiency\n", "\n", "\t\t\t\t\n", "#Calculation\n", "\t\t\t\t#Converting relation eff = (2*sig)/(1+sig**2) into 2nd degree polynomial of sig\n", "sig = ((2-(math.sqrt(4-(4*eff*eff))))/(2*eff)) \t\t\t\t#Jet speed ratio\n", "Cj = u/sig \t\t\t\t#Jet velocity in m/s\n", "\n", "\t\t\t\t\n", "#Output\n", "print 'Jet velocity is %3.2f m/s'%Cj\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Jet velocity is 3322.88 m/s\n" ] } ], "prompt_number": 27 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 8.7.46 page : 40" ] }, { "cell_type": "code", "collapsed": false, "input": [ "import math \n", "\n", "\t\t\t\t\n", "#Input data\n", "Cj = 2700. \t\t\t\t#Jet velocity in m/s\n", "u = 1350. \t\t\t\t#Flight velocity in m/s\n", "m = 78.6 \t\t\t\t#Propellent flow in kg/s\n", "\n", "\t\t\t\t\n", "#Calculation\n", "F = m*Cj*10**-3 \t\t\t\t#Thrust in kN\n", "P = F*u*10**-3 \t\t\t\t#Thrust power in MW\n", "sig = u/Cj \t\t\t\t#Jet speed ratio\n", "eff = ((2*sig)/(1+sig**2))*100 \t\t\t\t#Propulsive efficiency in %\n", "\n", "\t\t\t\t\n", "#Output\n", "print 'Thrust is %3.1f kN \\\n", "\\nThrust power is %3.2f MW \\\n", "\\nPropulsive efficiency is %3i percent'%(F,P,eff)\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Thrust is 212.2 kN \n", "Thrust power is 286.50 MW \n", "Propulsive efficiency is 80 percent\n" ] } ], "prompt_number": 3 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 47 page : 40" ] }, { "cell_type": "code", "collapsed": false, "input": [ "import math \n", "\n", "\t\t\t\t\n", "#Input data\n", "D = 12683.*1000 \t\t\t\t#Diameter of Earth in m\n", "g = 9.81 \t\t\t\t#Acceleration due to gravity in m/s\n", "h = 500.*1000 \t\t\t\t#Altitude in m\n", "\n", "\t\t\t\t\n", "#Calculation\n", "Uorb = (D/2)*math.sqrt(g/((D/2)+h)) \t\t\t\t#Orbital velocity in m/s\n", "Uesc = math.sqrt(2)*Uorb \t\t\t\t#Escape velocity in m/s\n", "\n", "\t\t\t\t\n", "#Output\n", "print 'Orbital velocity is %3.2f m/s \\\n", "\\nEscape velocity is %3.2f m/s'%(Uorb,Uesc)\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Orbital velocity is 7593.65 m/s \n", "Escape velocity is 10739.05 m/s\n" ] } ], "prompt_number": 2 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 48 page : 40" ] }, { "cell_type": "code", "collapsed": false, "input": [ "import math \n", "\n", "\t\t\t\t\n", "#Input data\n", "u = 10080*(5./18) \t\t\t\t#Flight velocity in m/s\n", "Cj = 1400. \t\t\t\t#Jet velocity in m/s\n", "m = 5. \t\t\t\t#Propellent flow in kg/s\n", "\n", "\t\t\t\t\n", "#Calculation\n", "F = m*Cj*10**-3 \t\t\t\t#Thrust in kN\n", "P = F*u*10**-3 \t\t\t\t#Thrust power in MW\n", "sig = u/Cj \t\t\t\t#Jet speed ratio\n", "eff = ((2*sig)/(1+sig**2)) \t\t\t\t#Propulsive efficiency \n", "\n", "\t\t\t\t\n", "#Output\n", "print 'Propulsive power is %3.1f MW \\\n", "\\nPropulsive efficiency is %3.1f'%(P,eff)\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Propulsive power is 19.6 MW \n", "Propulsive efficiency is 0.8\n" ] } ], "prompt_number": 1 } ], "metadata": {} } ] }