{ "metadata": { "name": "", "signature": "sha256:f32ce99f1a0136b5cca3224fda443fb508c92875ffc981f9eb147519b1c553ca" }, "nbformat": 3, "nbformat_minor": 0, "worksheets": [ { "cells": [ { "cell_type": "heading", "level": 1, "metadata": {}, "source": [ "Chapter 5 : Flow of a Compressible Ideal Fluid" ] }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 5.1 Page No : 152" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\t\t\n", "\n", "# variables\n", "v1 = 100.;\t\t# fps\n", "p1 = 50.;\t\t# psia\n", "T1 = 300.;\t\t# degreeF\n", "v2 = 500.;\t\t# fps\n", "Cp = 186.5;\n", "gam = 1.4;\n", "\n", "# calculations \n", "T2 = T1 - (v2**2 - v1**2)/(2*36.2*Cp);\n", "p2 = p1*(1 - (v2**2 - v1**2)/(2*36.2*53.3*(T1+460)*(gam/(gam-1))))**(1/0.286);\n", "\n", "# results \n", "print 'T2 = %d degreeF'%(round(T2,-1));\n", "print 'p2 = %.1f psia'%(p2);\n", "\n", "#there is an error in the answer given in textbook" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "T2 = 280 degreeF\n", "p2 = 46.0 psia\n" ] } ], "prompt_number": 3 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 5.2 Page No : 153" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "import math \n", "\t\t\n", "# variables\n", "p1 = 300.;\t\t# psia\n", "T1 = 900.;\t\t# degreeF\n", "p2 = 200.;\t\t# psia\n", "T2 = 780.;\t\t# degreeF\n", "H2 = 1414.;\t\t#Btu/lb\n", "H1 = 1471.;\t\t# Btu/lb\n", "\n", "# calculations \n", "V2 = math.sqrt(2*31.1*778*(H1-H2));\n", "\n", "# results \n", "print 'T2 = %d degreeF and V2 = %d fps'%(T2,V2);" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "T2 = 780 degreeF and V2 = 1660 fps\n" ] } ], "prompt_number": 4 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 5.3 Page No : 155" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "import math \n", "\t\t\n", "# variables\n", "v = 586.;\t\t# fps\n", "p = 13.;\t\t# psia\n", "T = 0.;\t\t# degreeF\n", "gam = 1.4;\n", "\n", "# calculations \n", "rho_0 = p*144/(32.2*53.3*(460+T));\n", "a_0 = math.sqrt(gam*32.2*53.3*(T+460));\n", "M_0 = v/a_0;\n", "p_8_approx = p+(0.5/144)*rho_0*v**2 *(1+0.25*M_0**2);\n", "p_8_exact = p*(1+M_0**2 *(gam-1)/2)**(gam/(gam-1));\n", "T_8 = v**2 /(2*32.2*186.5) +460;\n", "rho_8 = p_8_exact*144/(T_8*32.2*53.3);\n", "\n", "# results \n", "print 'At stagnetion point, p = %.2f psia, T = %.1f degreeR and density = %.5f slug/cuft'%(p_8_exact,T_8,rho_8);" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "At stagnetion point, p = 16.05 psia, T = 488.6 degreeR and density = 0.00276 slug/cuft\n" ] } ], "prompt_number": 5 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 5.4 pageno : 159" ] }, { "cell_type": "code", "collapsed": false, "input": [ "import math\n", "\n", "# variables\n", "g = 32.2\n", "k = 1.40\n", "R = 53.3\n", "A2 = 0.005454\n", "p1 = 114.7 * 144\n", "T1 = 560\n", "\n", "# calculations\n", "y1 = p1 /(R * T1)\n", "p2 = 0.528 * 114.7\n", "G1 = math.sqrt(g*k/R * (2/(k+1))**((k+1)/(k-1))) * A2*p1/math.sqrt(T1)\n", "\n", "p2 = 94.7 # psia\n", "p2byp1 = 0.825\n", "G = A2*math.sqrt( (2*g*k)/(k-1) * p1*y1 * ((p2byp1)**(2/k) - (p2byp1)**((k+1)/k)))\n", "# result\n", "print \"part a\"\n", "print \"G = %.2f lb/sec\"%G1\n", "print \"\\npart b\"\n", "print \"G = %.2f lb/sec\"%G" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "part a\n", "G = 2.03 lb/sec\n", "\n", "part b\n", "G = 1.58 lb/sec\n" ] } ], "prompt_number": 1 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 5.5 Page No : 161" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "import math \n", "\t\t\n", "# variables\n", "d = 1.;\t\t # in\n", "p = 100.;\t\t# psi\n", "T = 10.;\t\t# degreeF\n", "p_i = 80.;\t\t#psi\n", "p_b = 14.7;\t\t#psi\n", "p1 = 16520.;\t# psfa\n", "gam1 = 0.553;\t# lb/cuft\n", "k = 0.874;\n", "\n", "# calculations \n", "G = (0.5*k*0.25*math.pi*(d/12)**2 /(1-(2./3)**4)) *math.sqrt(2*32.2*(p-p_i)*144/gam1);\n", "\n", "# results \n", "print 'flow rate = %.2f lb/sec'%(G);" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "flow rate = 1.72 lb/sec\n" ] } ], "prompt_number": 6 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 5.6 Page No : 163" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "import math \n", "\n", "# variables\t\t\n", "d = 1.;\t\t# in\n", "p_r = 100.;\t\t#psi\n", "T_r = 100.;\t\t# degreeF\n", "p_b = 14.7;\t\t# psi\n", "p3 = 14.7;\t\t#psi\n", "G = 2.03;\t\t# lb/sec\n", "gam1 = 0.553;\n", "gam = 1.4;\n", "\n", "# calculations \n", "V3 = math.sqrt(2*32.2*(gam/(gam-1))*(p_r+p_b)*144/gam1 *(1-(p3/(p_r+p_b))**((gam-1)/gam)));\n", "T3 = (T_r+460) - V3**2 /(2*32.2*186.5);\n", "a3 = math.sqrt(gam*32.2*53.3*T3);\n", "M3 = V3/a3;\n", "A3 = G/(gam1*V3);\n", "d3 = (A3/(0.25*math.pi))**(1./2);\n", "p3_dash = 103.3;\t\t# psia\n", "p_B = p3*(1+ (2*gam/(gam+1))*(M3**2 -1));\n", "\n", "# results \n", "print 'V3 = %d fps, a3 = %d fps, M3 = %.2f '%(V3,a3,M3);\n", "print 'p3_dash = %.1f psia, p_B = %.1f psia'%(p3_dash,p_B);\n", "\n", "#there are rounding-off errors in the answer given in textbook" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "V3 = 1728 fps, a3 = 864 fps, M3 = 2.00 \n", "p3_dash = 103.3 psia, p_B = 66.1 psia\n" ] } ], "prompt_number": 6 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 5.7 Page No : 166" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "import math \n", "\t\t\n", "# variables\n", "V_0 = 586.;\t\t# fps\n", "t_0 = 0;\t\t# degreeF\n", "P_0 = 13.;\t\t# psia\n", "a_0 = 1052.;\t\t# fps\n", "M_0 = 0.557;\n", "V_A = 800.;\t\t#fps\n", "V_B = 900.;\t\t#fps\n", "gam = 1.4;\n", "\n", "# calculations \n", "T_A = 488.5- V_A**2 /(2*32.2*186.5);\n", "T_B = 488.5- V_B**2 /(2*32.2*186.5); \n", "p_A = 16.18*(T_A/488.5)**(gam/(gam-1));\n", "p_B = 16.18*(T_B/488.5)**(gam/(gam-1));\n", "a_A = math.sqrt(gam*32.2*53.3*T_A);\n", "a_B = math.sqrt(gam*32.2*53.3*T_B);\n", "M_A = V_A/a_A;\n", "M_B = V_B/a_B;\n", "\n", "# results \n", "print 'At point A, p = %.2f psia, T = %.1f degreeR, a = %d fps, M = %.3f'%(p_A,T_A,a_A,M_A);\n", "print 'At point B, p = %.2f psia, T = %.1f degreeR, a = %d fps, M = %.1f'%(p_B,T_B,a_B,M_B);\n", "\n", "#answer differs due to rounding-off errors in textbook" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "At point A, p = 10.80 psia, T = 435.2 degreeR, a = 1022 fps, M = 0.782\n", "At point B, p = 9.62 psia, T = 421.1 degreeR, a = 1005 fps, M = 0.9\n" ] } ], "prompt_number": 12 } ], "metadata": {} } ] }