{ "metadata": { "name": "", "signature": "sha256:fb647d6d0a9fd1fab503f1e20b9cd4c1b8f196f963f97a28e2375980e25dde26" }, "nbformat": 3, "nbformat_minor": 0, "worksheets": [ { "cells": [ { "cell_type": "heading", "level": 1, "metadata": {}, "source": [ "Chapter 7 : Steady, One-Dimensional, Irreversible Flow" ] }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 7.1 Page No : 213" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\t\n", "#initialisation of variables\n", "r= 1.5\n", "f= 0.025 # friction factor\n", "\t\n", "#CALCULATIONS\n", "r1= (2/f)*(r**2-1)\n", "\t\n", "#RESULTS\n", "print 'ratio L/D2 = %.f'%(r1)\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "ratio L/D2 = 100\n" ] } ], "prompt_number": 1 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 7.2 Page No : 214" ] }, { "cell_type": "code", "collapsed": false, "input": [ "import math\t\n", "#initialisation of variables\n", "a= 6. \t#degrees angle\n", "r= 1.5\n", "l= 100. \t#ft\n", "f= 0.025\n", "K= 0.15\n", "\t\n", "#CALCULATIONS\n", "R= r**4-1\n", "R1= 1/math.tan(math.radians(a/2))*(1-(1./r))\n", "p1= f*l\n", "p2= 2.5*(l-p1)/l\n", "p3= (1-r**2)**2\n", "p4= K*p3\n", "pt= p4+p2\n", "\t\n", "#RESULTS\n", "print ' lowest ratio = %.2f'%(R)\n", "print ' contribtuion of friction in pipe = %.3f lbf/ft**2'%(p1)\n", "print ' contribtuion of diffuser in pipe = %.3f lbf/ft**2'%(p2)\n", "print ' stagnant pressure drop = %.3f lbf/ft**2'%(p3)\n", "print ' contribtuion of friction in pipe after reduction = %.3f lbf/ft**2'%(pt)\n", "\n", "# note : rounding off error" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ " lowest ratio = 4.06\n", " contribtuion of friction in pipe = 2.500 lbf/ft**2\n", " contribtuion of diffuser in pipe = 2.438 lbf/ft**2\n", " stagnant pressure drop = 1.562 lbf/ft**2\n", " contribtuion of friction in pipe after reduction = 2.672 lbf/ft**2\n" ] } ], "prompt_number": 2 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 7.3 Page No : 219" ] }, { "cell_type": "code", "collapsed": false, "input": [ "import math \n", "\t\n", "#initialisation of variables\n", "d= 4. \t #in galvanised iron pipe diameter\n", "q= 0.5 \t #ft**3/sec flow rate\n", "w= 62.4 \t#lb/ft**3 density\n", "u= 2.7*10**-5 \t#lbf sec/ft**2 viscosity\n", "e= 0.0005 \t#ft\n", "g= 32.1 \t#ft/sec**2 acceleration\n", "f= 0.0235\n", "lt= 400. \t#ft long\n", "\t\n", "#CALCULATIONS\n", "V= 4*q/(math.pi*(d/12)**2)\n", "Re= w*V*(d/12)/(u*g)\n", "r= e/(d/12)\n", "dz= (V**2/(2*g))*(1.7+f*lt/(d/12))\n", "\t\n", "#RESULTS\n", "print ' mean flow velocity = %.2f ft/sec'%(V)\n", "print ' Reynolds number = %.2e'%(Re)\n", "print ' Relative roughness = %.4f'%(r)\n", "print ' difference in the levels of water = %.1f ft'%(dz)\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ " mean flow velocity = 5.73 ft/sec\n", " Reynolds number = 1.38e+05\n", " Relative roughness = 0.0015\n", " difference in the levels of water = 15.3 ft\n" ] } ], "prompt_number": 3 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 7.4 Page No : 220" ] }, { "cell_type": "code", "collapsed": false, "input": [ "import math \n", "\t\n", "#initialisation of variables\n", "d= 4. \t#in\n", "v= 6.64 \t#ft/sec\n", "\t\n", "#CALCULATIONS\n", "Q= math.pi*0.25*(d/12)**2*v\n", "\t\n", "#RESULTS\n", "print 'Flow rate= %.3f ft**3/sec'%(Q)\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Flow rate= 0.579 ft**3/sec\n" ] } ], "prompt_number": 5 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 7.5 Page No : 221" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\t\n", "#initialisation of variables\n", "d= 0.366 \t#ft\n", "i= 12\n", "\t\n", "#CALCULATIONS\n", "pd= d*i\n", "\t\n", "#RESULTS\n", "print 'Required pipe diameter = %.2f in'%(pd)\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Required pipe diameter = 4.39 in\n" ] } ], "prompt_number": 6 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 7.6 Page No : 222" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\t\n", "#initialisation of variables\n", "Ps1= 1050. \t#lbf/ft**2\n", "fr= 10.7\n", "p= 36.6 \t#lbf/ft**2\n", "p1= 195. \t#lbf/ft**2\n", "fr1= 16.\n", "fr2= 1.8\n", "\t\n", "#CALCULATIONS\n", "deltap = (p+957+p1+Ps1)\n", "p2= round(fr*p)\n", "dp= Ps1-p2\n", "lc= round(dp/p)\n", "sp= Ps1+p1-p*(fr1+fr2)\n", "lc1= sp/p\n", "\n", "#RESULTS\n", "print ' Pressure = %.f lbf/ft**2'%(round(deltap,-1))\n", "print ' pressure difference = %.f lbf/ft**2'%(dp)\n", "print ' Loss coefficient = %.f '%(lc)\n", "print ' Loss coefficient = %.1f '%(lc1)\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ " Pressure = 2240 lbf/ft**2\n", " pressure difference = 658 lbf/ft**2\n", " Loss coefficient = 18 \n", " Loss coefficient = 16.2 \n" ] } ], "prompt_number": 5 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 7.7 Page No : 232" ] }, { "cell_type": "code", "collapsed": false, "input": [ "import math \n", "\t\n", "#initialisation of variables\n", "p1= 50. \t#lbf/in**2 pressure\n", "R= 96.3 \t#ft lbf/lbm R\n", "T= 80. \t #F temperature\n", "p2= 20. \t#lbf/in**2 pressure\n", "r= 1.31\n", "u= 2.34*10**-7 \t#lbf sec/ft**2\n", "e= 0.00005 \t #ft\n", "m= 5.*10**4 \t#lbm/sec\n", "d= 1.5 \t #ft\n", "g= 32.2 \t #ft/sec**2\n", "f= 0.113\n", "\t\n", "#CALCULATIONS\n", "w1= p1*144/(R*(460+T))\n", "V1= 4*(m/3600)/(math.pi*w1*d**2)\n", "Ma1= V1/(r*R*g*(460+T))**0.5\n", "Re= w1*V1*d/(u*g)\n", "dx= (((1/(r*Ma1**2))*10*(1-(p2/p1)**2))+math.log(p2/p1))*d/f\n", "\t\n", "#RESULTS\n", "print ' density = %.3f lbm/ft**3'%(w1)\n", "print ' mean flow velocity = %.1f ft/sec'%(V1)\n", "print ' Match number = %.4f '%(Ma1)\n", "print ' Reynolds number = %.2e '%(Re)\n", "print ' Length of pipe = %.2e ft'%(dx)\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ " density = 0.138 lbm/ft**3\n", " mean flow velocity = 56.8 ft/sec\n", " Match number = 0.0383 \n", " Reynolds number = 1.56e+06 \n", " Length of pipe = 5.79e+04 ft\n" ] } ], "prompt_number": 4 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 7.9 Page No : 238" ] }, { "cell_type": "code", "collapsed": false, "input": [ "import math \n", "\t\n", "#initialisation of variables\n", "r= 1.4\n", "R= 53.3 \t#ft lbf/lbm R\n", "g= 32.2 \t#ft/sec**2\n", "T1= 410. \t#R temperature\n", "v= 2500. \t#ft/sec steadility\n", "P1= 628. \t#lbf/in**2 pressure\n", "\t\n", "#CALCULATIONS\n", "v1= int(math.sqrt(r*g*R*T1))\n", "Ma1= round(v/v1,2)\n", "Ts1= int(T1*(1+0.5*(r-1)*Ma1**2))\n", "Ps1= P1*(1+0.5*(r-1)*Ma1**2)**(r/(r-1))\n", "Ps2= Ps1*((r+1)/(2*r*Ma1**2-r+1))**(1/(r-1))*(0.5*(r+1)*Ma1**2/(1+0.5*(r-1)*Ma1**2))**(r/(r-1))\n", "\n", "#RESULTS\n", "print ' acoustic velocity = %.f ft/sec'%(v1)\n", "print ' Match number = %.2f '%(Ma1)\n", "print ' Stagnition temperature = %.f R'%(Ts1)\n", "print ' Stagnition pressure = %.f lbf/ft**2'%(Ps1)\n", "print ' Stagnition pressure = %.f lbf/ft**2'%(Ps2)\n", "\n", "# note : answer in book is wrong. Please check manually.\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ " acoustic velocity = 992 ft/sec\n", " Match number = 2.52 \n", " Stagnition temperature = 930 R\n", " Stagnition pressure = 11069 lbf/ft**2\n", " Stagnition pressure = 5435 lbf/ft**2\n" ] } ], "prompt_number": 5 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 7.10 Page No : 245" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "#initialisation of variables\n", "p2= 67.2 \t#lbf/in**2 pressure\n", "p1= 63. \t#lbf/in62 pressure\n", "r= 1.4\n", "n= 0.6 # efficiency\n", "T1= 870. \t#R temperature\n", "ma1= 0.8 \t#ft/sec mach number\n", "\n", "#CALCULATIONS\n", "dt= (p2/p1)**((r-1)/r)-1\n", "dt1= dt/n\n", "T2= T1*(1+dt1)\n", "Ts1= T1*(1+0.5*(r-1)*ma1**2)\n", "ps1= p1*(1+0.5*(r-1)*ma1**2)**(r/(r-1))\n", "ps2= p2*(Ts1/T2)**(r/(r-1))\n", "dp= ps1-ps2\n", "\n", "#RESULTS\n", "print ' dT = %.5f '%(dt)\n", "print ' dT1 = %.5f '%(dt1)\n", "print ' Temperature = %.f R'%(T2)\n", "print ' Temperature = %.1f R'%(Ts1)\n", "print ' Pressure = %.1f lbf/in**2'%(ps1)\n", "print ' Pressure = %.1f lbf/in**2'%(ps2)\n", "print ' pressure difference = %.1f lbf/in**2'%(dp)\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ " dT = 0.01861 \n", " dT1 = 0.03102 \n", " Temperature = 897 R\n", " Temperature = 981.4 R\n", " Pressure = 96.0 lbf/in**2\n", " Pressure = 92.0 lbf/in**2\n", " pressure difference = 4.0 lbf/in**2\n" ] } ], "prompt_number": 6 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 7.11 Page No : 246" ] }, { "cell_type": "code", "collapsed": false, "input": [ "import math \n", "\n", "#initialisation of variables\n", "r= 1.4\n", "ma3= 3. \t#ft/sec mach number\n", "ps= 80. \t#lbf/ft**2 pressure\n", "Ts= 840. \t#R temperature\n", "r1= 53.3 \t#ft lbm/ft**3\n", "A3= 2. \t#in**2 flow area\n", "g= 32.2 \t#ft/sec**2\n", "ma1= 1.6\n", "\n", "#CALCULATIONS\n", "R= (1+(r-1)*0.5*ma3**2)**(r/(r-1))\n", "p3= ps/R\n", "R1= 1+0.5*(r-1)*ma3**2\n", "T3= Ts/R1\n", "w3= p3*144/(r1*T3)\n", "V3= ma3*math.sqrt(r*r1*g*T3)\n", "m= w3*V3*A3/144\n", "ra= ((r+1)/(2*r*ma1**2-(r-1)))**(1/(r-1))*(0.5*(r+1)*ma1**2/(1+0.5*(r-1)*ma1**2))**(r/(r-1))\n", "ps2= ps*ra\n", "dp= ps-ps2\n", "\n", "#RESULTS\n", "print ' outlet pressure = %.2f lbf/in**2'%(p3)\n", "print ' outlet temperature = %.f R'%(T3)\n", "print ' mass flow rate = %.3f lbm/sec'%(m)\n", "print ' ps2 = %.1f lbf/in**2'%(ps2)\n", "print ' Stagnation pressure loss = %.1f lbf/in**2'%(dp)\n", "\n", "# rounding off error" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ " outlet pressure = 2.18 lbf/in**2\n", " outlet temperature = 300 R\n", " mass flow rate = 0.694 lbm/sec\n", " ps2 = 71.6 lbf/in**2\n", " Stagnation pressure loss = 8.4 lbf/in**2\n" ] } ], "prompt_number": 7 } ], "metadata": {} } ] }