{ "metadata": { "name": "", "signature": "sha256:204da51ebf9aa715601d60f6e1aaa3c9734a35c1b9cad7274440a88878e8202c" }, "nbformat": 3, "nbformat_minor": 0, "worksheets": [ { "cells": [ { "cell_type": "heading", "level": 1, "metadata": {}, "source": [ "Chapter 4 : Energy Considerations in Steady Flow" ] }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 4.1 Page No : 93" ] }, { "cell_type": "code", "collapsed": false, "input": [ "import math \n", "\t\n", "#Initialization of variables\n", "d = 1.26 #specific gravity\n", "d = 24. \t#in\n", "d2 = 60. #cm\n", "Q = 25. \t#cfs\n", "Q2 = 700. \t#L/s\n", "dout = 12. \t#in\n", "dout2 = 30./100 \t#m\n", "z = 3. \t #ft\n", "z2 = 1. \t#m\n", "P1 = 45. \t#psi\n", "P2 = 300. \t#kN/m**2\n", "gamma = 9.81 \t#kN/m**3\n", "\t\n", "#calculations\n", "V1 = d/math.pi\n", "V2 = d*4/math.pi\n", "pf = (P1*144/(1.26*62.4) + (V1**2)/64.4 - V2**2 /64.4 +z)*1.26*62.4/144\n", "V1 = Q2/1000/(math.pi*dout2**2)\n", "V2 = 4*V1\n", "p2f = ((P2/(1.26*gamma)) + V1**2 /(2*gamma) -V2**2 /(2*gamma) +z2)*1.26*gamma\n", "\n", "#Results\n", "print \" English units\"\n", "print \" Pressure at point 2 = %.1f psi \"%(pf)\n", "print \" \\n SI Units\"\n", "print \" Pressure at point 2 = %.d kN/m**2 \"%(p2f)\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ " English units\n", " Pressure at point 2 = 39.2 psi \n", " \n", " SI Units\n", " Pressure at point 2 = 254 kN/m**2 \n" ] } ], "prompt_number": 3 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 4.2 Page No : 94" ] }, { "cell_type": "code", "collapsed": false, "input": [ "import math \n", "\t\n", "#Initialization of variables\n", "h = 20. \t#m\n", "c = 4187. \t#N m /(kg K)\n", "g = 9.81\n", "\t\n", "#calculations\n", "dT = g*h/c\n", "\t\n", "#Results\n", "print \"Increase in temperature of water = %.3f K\"%(dT)\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Increase in temperature of water = 0.047 K\n" ] } ], "prompt_number": 2 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 4.3 Page No : 96" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\t\n", "#Initialization of variables\n", "sg = 1.26 #specific gravity of liquid\n", "sg2 = 1.26 #\n", "HP = 22.\n", "HP2 = 16.\n", "\t\n", "#calculations\n", "hp = HP*550/(sg*62.4) \t#divide by Q\n", "Q = 14.2 \t#cfs\n", "print \"In English units, By trial Q = %.1f cfs\"%(Q)\n", "hp2 = HP2*1000/(sg2*9.81)\n", "Q2 = 0.42 \t#m**3/s\n", "print \" In SI units, By trial Q = %.2f m**3/s\"%(Q2)\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "In English units, By trial Q = 14.2 cfs\n", " In SI units, By trial Q = 0.42 m**3/s\n" ] } ], "prompt_number": 4 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 4.4 Page No : 96" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\t\n", "#Initialization of variables\n", "g = 9810. \t#N/m**3\n", "Q = 10 \t #m**3/s\n", "H = 20 \t #m\n", "\t\n", "#calculations\n", "Rate = g*Q*H/1000\n", "\t\n", "#Results\n", "print \"Rate of energy loss = %d kW\"%(Rate-2)\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Rate of energy loss = 1960 kW\n" ] } ], "prompt_number": 5 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 4.5 Page No : 98" ] }, { "cell_type": "code", "collapsed": false, "input": [ "import math \n", "\t\n", "#Initialization of variables\n", "s = 0.86\n", "P2 = 3.8 \t#pressure - psia\n", "Patm = 26.8 \t#atmospheric pressure - Hg\n", "SPatm = 29.9 \t#in of Hg\n", "psi = 14.7 \t#psia\n", "\t\n", "#calculations\n", "Pa = Patm*psi/SPatm\n", "Pcrit = -(Pa-P2)*144/(s*62.4)\n", "Q = math.sqrt((-Pcrit+ 10*144/(s*62.4))*64.4*math.pi**2 /(-1/2.25**2 + 1/0.25**2 ))\n", "\t\n", "#Results\n", "print \"Max. theoretical flow = %.1f cfs\"%(Q)\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Max. theoretical flow = 45.7 cfs\n" ] } ], "prompt_number": 6 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 4.6 Page No : 104" ] }, { "cell_type": "code", "collapsed": false, "input": [ "import math \n", "\t\n", "#Initialization of variables\n", "z = 3. \t#ft\n", "s = 0.82\n", "\t\n", "#calculations\n", "ua = math.sqrt(z*2*32.2)\n", "ub = math.sqrt(2*32.2*(-2*(1-s) +ua**2 /(2*32.2)))\n", "\t\n", "#Results\n", "print \"Velocity at B = %.1f fps\"%(ub)\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Velocity at B = 13.0 fps\n" ] } ], "prompt_number": 7 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 4.7 Page No : 108" ] }, { "cell_type": "code", "collapsed": false, "input": [ "import math \n", "\t\n", "#Initialization of variables\n", "d = 3. \t#in\n", "x1 = 0.5**2\n", "x2 = 0.75**2\n", "z = 80. \t#ft\n", "z3 = 10. \t#ft\n", "\t\n", "#calculations\n", "print (\"Using Bernoullis theorem\")\n", "v3 = 29.7 \t#fps\n", "Q = math.pi /4 *(d/12)**2 *v3\n", "hls = 5*(x1*v3)**2 /(2*32.2)\n", "hld = 12*(x2*v3)**2 /(2*32.2)\n", "\t\n", "#Results\n", "print \"Head loss in suction pipe = %.1f ft\"%(hls)\n", "print \" Head loss in discharge pipe = %.1f ft\"%(hld)\n", "print \" Flow rate = %.2f cfs\"%(Q)\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Using Bernoullis theorem\n", "Head loss in suction pipe = 4.3 ft\n", " Head loss in discharge pipe = 52.0 ft\n", " Flow rate = 1.46 cfs\n" ] } ], "prompt_number": 5 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 4.8 Page No : 109" ] }, { "cell_type": "code", "collapsed": false, "input": [ "import math \n", "\t\n", "#Initialization of variables\n", "z1 = 2.\n", "z2 = 0.8\n", "\t\n", "#calculations\n", "print (\"From equation of continuity, z1*v1 = z2*v2\")\n", "V1 = math.sqrt((z2-z1)*2*9.81/(1-z1**2 /z2**2))\n", "V2 = z1*V1/z2\n", "Q = z1*1*V1\n", "\t\n", "#Results\n", "print \"Flow rate = %.2f m**3/s\"%(Q)\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "From equation of continuity, z1*v1 = z2*v2\n", "Flow rate = 4.24 m**3/s\n" ] } ], "prompt_number": 9 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 4.9 Page No : 113" ] }, { "cell_type": "code", "collapsed": false, "input": [ "import math \n", "\t\n", "#Initialization of variables\n", "theta = 30. \t#degrees\n", "z = 10. \t#ft\n", "x = 60. \t #ft\n", "\t\n", "#calculations\n", "V = math.sqrt((0.5*32.2*69.3**2)/((x-math.sin(math.radians(theta)) *69.3)))\n", "\t\n", "#Results\n", "print \"velocity = %.0f fps\"%(V)\n", "\n", "# rounding off error" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "velocity = 55 fps\n" ] } ], "prompt_number": 1 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 4.10 Page No : 119" ] }, { "cell_type": "code", "collapsed": false, "input": [ "import math \n", "\t\n", "#Initialization of variables\n", "V = 60. \t#fps\n", "theta = 15. #degrees\n", "ra = 6/12. \t#ft\n", "rb = 8/12. \t#ft\n", "B = 1.5/12 \t#ft\n", "\t\n", "#calculations\n", "Vra = V*math.sin(math.radians(theta))\n", "Q = 2* math.pi*ra*B*Vra\n", "Vratio = ra/rb\n", "Vb = Vratio*V\n", "flow = (V**2 - Vb**2)/(2*32.2)\n", "\t\n", "#Results\n", "print \"Flow rate = %.2f cfs\"%(Q)\n", "print \" Velocity at b = %d fps\"%(Vb)\n", "print \" Pressure head = %.1f ft\"%(flow)\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Flow rate = 6.10 cfs\n", " Velocity at b = 45 fps\n", " Pressure head = 24.5 ft\n" ] } ], "prompt_number": 11 } ], "metadata": {} } ] }