{ "metadata": { "name": "", "signature": "sha256:97054b18dca6dd35f36356f17f04ac0dbb81bc69e4ec9c5130f6bdf970d306a2" }, "nbformat": 3, "nbformat_minor": 0, "worksheets": [ { "cells": [ { "cell_type": "heading", "level": 1, "metadata": {}, "source": [ "Chapter 16 : Reaction Turbines" ] }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 16.2 Page No : 525" ] }, { "cell_type": "code", "collapsed": false, "input": [ "import math \n", "from sympy.functions.elementary.trigonometric import acot\n", "\t\n", "#Initialization of variables\n", "ns = 20. \n", "eta = 0.925\n", "etah = 0.94\n", "BD = 0.1\n", "phie = 0.72\n", "g = 32.2\n", "alpha2 = 90. \t#degrees\n", "\t\n", "#calculations\n", "Cr = ns**2 /(67100*phie**2 *BD*eta)\n", "c1cos = etah/(2*phie)\n", "alpha = math.degrees(math.atan(Cr/c1cos))\n", "C1 = Cr/math.sin(alpha)\n", "#beta1 = 1/math.tan(math.radians((C1*math.cos(alpha) -phie)/(C1*math.sin(alpha))))\n", "cotb1 = (0.653 - phie)/0.1243\n", "beta1 = math.degrees(1./math.atan(cotb1))\n", "\n", "#Results\n", "print \"Alpha = %.2f degrees\"%(alpha)\n", "print \" Beta = %.2f degrees\"%(beta1)\n", "print (\"part b\")\n", "h = 402.\n", "n = 600. \t#rpm\n", "bhp = 3600.\n", "ns = n*math.sqrt(bhp) /h**(5./4)\n", "D = 153.2*phie*math.sqrt(h) /n\n", "B = BD*D\n", "Dt = D*0.735\n", "Ac = 0.95*math.pi*D*B\n", "Vr = Cr*math.sqrt(2*g*h)\n", "Q = Ac*Vr\n", "\t\n", "#Results\n", "print \" Breadth = %.3f ft\"%(B)\n", "print \" depth D = %.2f ft\"%(D)\n", "print \" velocity Vr = %d ft/s\"%(Vr)\n", "print \" Flow rate Q = %.1f cfs\"%(Q)\n", "\n", "# note : answers are slightly different because of rounding off error." ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Alpha = 10.78 degrees\n", " Beta = -115.90 degrees\n", "part b\n", " Breadth = 0.369 ft\n", " depth D = 3.69 ft\n", " velocity Vr = 20 ft/s\n", " Flow rate Q = 81.1 cfs\n" ] } ], "prompt_number": 1 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 16.3 Page No : 527" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\t\n", "#Initialization of variables\n", "ns = 70. \n", "z1 = 10. \t#ft\n", "z2 = 5000. \t#ft\n", "\t\n", "#calculations\n", "P1 = 12.2*144/62.4\n", "P2 = 0.26*144/62.4\n", "sigmac = 0.31\n", "h = (P1-P2-z1)/sigmac\n", "\t\n", "#Results\n", "print \"Max permissible head to assure against cavitation = %.f ft\"%(h)\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Max permissible head to assure against cavitation = 57 ft\n" ] } ], "prompt_number": 6 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 16.4 Page No : 529" ] }, { "cell_type": "code", "collapsed": false, "input": [ "import math \n", "\t\n", "#Initialization of variables\n", "Q = 600. \t#cfs\n", "z = 350. \t#ft\n", "eta = 0.9\n", "\t\n", "#calculations\n", "power = 62.4*Q*z*eta/550\n", "rpm = 75.\n", "n = 2.\n", "ns = rpm*math.sqrt(power/n) /z**(5./4)\n", "phi = 0.45\n", "D = 153.3*math.sqrt(z) *phi/rpm\n", "rpm2 = 600.\n", "ns2 = rpm2*math.sqrt(power/n) /z**(5./4)\n", "\t\n", "#Results\n", "print \"For two turbines, ns = %.2f\"%(ns)\n", "print \"For Francis turbines, ns = %d \"%(ns2)\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "For two turbines, ns = 5.13\n", "For Francis turbines, ns = 41 \n" ] } ], "prompt_number": 2 } ], "metadata": {} } ] }