{ "metadata": { "name": "", "signature": "sha256:b0248b236fb77321aca1aa897efa31136042f1022b99d1754ff155338956fea7" }, "nbformat": 3, "nbformat_minor": 0, "worksheets": [ { "cells": [ { "cell_type": "heading", "level": 1, "metadata": {}, "source": [ "Chapter9-Aerothermo-dynamics of Gas Turbines " ] }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Ex1-pg537" ] }, { "cell_type": "code", "collapsed": false, "input": [ "import math\n", "#calcualte inlet velocity and the exit double mach number and nozzle torque per unit mass flow rate \n", "Tt1=1800.\n", "M1=0.55\n", "alfa1=0.\n", "gm=1.33\n", "Cp=1157.\n", "alfa2=60.\n", "T1=Tt1/(1.+(gm-1)*M1**2/2.)\n", "a1=((gm-1.)*Cp*T1)**(1/2.)\n", "C1=a1*M1\n", "C2=C1/math.cos(alfa2/57.3)\n", "Tt2=Tt1\n", "T2=Tt2-C2**2/(2*Cp)\n", "a2=((gm-1)*Cp*T2)**(1/2)\n", "M2=C2/a2\n", "Ct2=C1*math.tan(alfa2/57.3)\n", "r=0.35\n", "t=0-r*Ct2\n", "print\"%s %.4f %s\"%(\"(a)Inlet velocity C1 in m/s :\",C1,\"\")\n", "print\"%s %.4f %s\"%(\"(b)The exit absolute Mach no. M2 :\",M2,\"\")\n", "print\"%s %.4f %s\"%(\"(c)Nozzle torque per unit mass flow rate for r1=r2=0.35m :\",t,\"\")" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "(a)Inlet velocity C1 in m/s : 444.9857 \n", "(b)The exit absolute Mach no. M2 : 889.8525 \n", "(c)Nozzle torque per unit mass flow rate for r1=r2=0.35m : -269.7102 \n" ] } ], "prompt_number": 1 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Ex2-pg538" ] }, { "cell_type": "code", "collapsed": false, "input": [ "import math\n", "#calculate the nozzle exit flow angle\n", "print(\"Example 9.2\")\n", "M2=1.0 ##i.e choked\n", "Tt2=1800.\n", "gm=1.33\n", "C1=445.\n", "Cp=1157.\n", "T2=Tt2/(1.+(gm-1.)*M2**2/2.)\n", "a2=((gm-1.)*Cp*T2)**(1/2.) \n", "M2=1\n", "C2=M2*a2\n", "alfa2=math.acos(C1/C2)*180/math.pi\n", "print\"%s %.4f %s\"%(\"Nozzle exit flow angle if M2=1 in degrees:\",alfa2,\"\")" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Example 9.2\n", "Nozzle exit flow angle if M2=1 in degrees: 54.5931 \n" ] } ], "prompt_number": 2 }, { "cell_type": "heading", "level": 1, "metadata": {}, "source": [ "Ex3-pg538" ] }, { "cell_type": "code", "collapsed": false, "input": [ "import math\n", "#calculate axial velocity and rotor velocity and degree of reaction at this radius\n", "C1=411.\n", "alfa2=60.\n", "C2=800.\n", "W2=450.\n", "alfa3=13.\n", "C3=411.\n", "Cz2=C2*math.cos(60/57.3)\n", "Cz3=C3*math.cos(13/57.3)\n", "Ct2m=Cz3*math.tan(60/57.3)\n", "Wt2m=(450.**2.-400**2.)**(1/2.)\n", "Um=Ct2m-Wt2m\n", "Ct3=C3*math.sin(13/57.3)\n", "Rm=1-(Ct2m+Ct3)/(2.*Um)\n", "print\"%s %.4f %s\"%(\"(a)The axial velocities up- and downstream of the rotor in m/s:\",Cz2,\"c\")\n", "print'%.4f'%(Cz3)\n", "print\"%s %.4f %s\"%(\"(b)The rotor velocity Um in m/s:\",Um,\"\")\n", "print\"%s %.4f %s\"%(\"(c)The degree of reaction at this radius :\",Rm,\"\")" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "(a)The axial velocities up- and downstream of the rotor in m/s: 400.0534 c\n", "400.4676\n", "(b)The rotor velocity Um in m/s: 487.3515 \n", "(c)The degree of reaction at this radius : 0.1936 \n" ] } ], "prompt_number": 4 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Ex4-pg553" ] }, { "cell_type": "code", "collapsed": false, "input": [ "import math\n", "#calculate the loss of turbine efficiency due to tip clearance\n", "Cd=0.5\n", "bm=-20.\n", "r=1.25\n", "phi=0.5\n", "chi=1.\n", "t=0.02\n", "\n", "De=Cd*t*r*(1-(chi/phi)*math.tan(bm/57.3))**(1/2.)\n", "print\"%s %.4f %s\"%(\"Loss of the turbine efficiency (eta0 times) :\",De,\"\")" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Loss of the turbine efficiency (eta0 times) : 0.0164 \n" ] } ], "prompt_number": 5 }, { "cell_type": "heading", "level": 1, "metadata": {}, "source": [ "Ex5-pg560" ] }, { "cell_type": "code", "collapsed": false, "input": [ "import math\n", "#calculate gas static temperature and adibatic wall temperature on the nozzle for a turbulent boundary layer \n", "Tt=1700. ##total gas temp at exit\n", "gm=1.33 ##gamma\n", "Cp=1157. ##in J/kg.K\n", "M2=1. ##local gas Mach no.\n", "Pr=0.71 ## Prandtl no.\n", "W2=455. ## gas speed relative to rotor\n", "Tg=Tt/(1.+(gm-1)*(M2**2)/2.)\n", "print\"%s %.3f %s \"%(\"The gas static temperature Tg in K:\",Tg,\"\")\n", "a2=((gm-1)*Cp*Tg)**(1/2.)\n", "C2=a2\n", "r=Pr**(1/3.)\n", "Taw=Tg+Pr**(1/3.)*C2**2./(Cp)\n", "print\"%s %.3f %s \"%(\"The adiabatic wall temperatue Taw on the nozzle for a turbulent boundary layer in K:\",Taw,\"\")\n", "Ttr=Tg+(W2**2)/(2*Cp)\n", "Tawl=Tg+Pr**(1/2)*C2**2/(Cp)\n", "print\"%s %.3f %s \"%(\"The adiabatic wall temperature on the nozzle for a laminar boundary layer in K: \",Tawl,\"\")\n", "print\"%s %.3f %s \"%(\"The rotor temperature of the gas on the rotor in K:\",Ttr,\"\")" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "The gas static temperature Tg in K: 1459.227 \n", "The adiabatic wall temperatue Taw on the nozzle for a turbulent boundary layer in K: 1888.820 \n", "The adiabatic wall temperature on the nozzle for a laminar boundary layer in K: 1940.773 \n", "The rotor temperature of the gas on the rotor in K: 1548.694 \n" ] } ], "prompt_number": 6 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Ex6-pg564" ] }, { "cell_type": "code", "collapsed": false, "input": [ "import math\n", "#calculate cooling fraction\n", "T0=288. ##in K\n", "p0=100. ##in kPa\n", "Tt3=800. ##in K\n", "gm=1.4\n", "Cpc=1.0045 ##kJ/Kg.K\n", "pc=25.\n", "ec=0.9\n", "Tt4=2000. ##in K\n", "gmc=1.33\n", "Cpg=1.188 ##kJ/Kg.K\n", "Stg=0.005 ##Gas-side Stanton no.\n", "Taw=2000. ##in K\n", "ptg=2.5 ##in Mpa\n", "Tawd=1200. ## desired temp. in K\n", "d=2. ##thickness of internally cooled wall in mm\n", "bms=2. ##blade mean solidity in HPT\n", "kw=14.9 ##in W/m.K\n", "Twc=870. ##in K\n", "S=1/2. ##S=Stc/Stg\n", "e=(Cpc/Cpg)*S*(Twc-Tt3)/(Tt4-Tawd)\n", "print\"%s %.4f %s\"%(\"Cooling fraction :\",e,\"\")\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Cooling fraction : 0.0370 \n" ] } ], "prompt_number": 7 } ], "metadata": {} } ] }