{ "metadata": { "name": "", "signature": "sha256:62ceb66cf48441d19499a6332c57808da0a2f8834a586c75e2d7d1a835c045df" }, "nbformat": 3, "nbformat_minor": 0, "worksheets": [ { "cells": [ { "cell_type": "heading", "level": 1, "metadata": {}, "source": [ "Chapter 9 : Impact of Jets" ] }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 9.1 Page No : 171" ] }, { "cell_type": "code", "collapsed": false, "input": [ "import math \n", "\n", "#initialisation of variables\n", "d= 2. \t #in\n", "V= 210. \t#ft/sec\n", "V1= 50. \t#ft/sec\n", "g= 32.2 \t#ft/sec**2\n", "w= 62.4 \t#lb/ft**3\n", "\n", "#CALCULATIONS\n", "M= math.pi*V*w/(4*36*g)\n", "F= M*V\n", "dV= V-V1\n", "M1= math.pi*dV*w/(4*36*g)\n", "F1= M1*dV\n", "W= F1*V1\n", "F2= M*dV\n", "W1= F2*V1\n", "\n", "#RESULTS\n", "print 'Force on plate = %.f lb'%(F+1)\n", "print ' Force on plate = %.f lb'%(F1)\n", "print ' Work done/sec = %.f ft-lb/sec'%(W)\n", "print ' Force on plate = %.f lb'%(F2)\n", "print ' Work done/sec = %.f ft-lb/sec'%(round(W1,-3))\n", "\n", "#The answer is a bit different due to rounding off error in textbook\n", "\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Force on plate = 1865 lb\n", " Force on plate = 1082 lb\n", " Work done/sec = 54116 ft-lb/sec\n", " Force on plate = 1421 lb\n", " Work done/sec = 71000 ft-lb/sec\n" ] } ], "prompt_number": 1 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 9.2 Page No : 172" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "import math \n", "\n", "#initialisation of variables\n", "v1= 15. \t#ft/sec\n", "v2= 40. \t#ft/sec\n", "a= 30. \t#degrees\n", "b= 150. \t#degrees\n", "v= 15.27 \t#ft/sec\n", "g= 32.2 \t#ft/sec**2\n", "\n", "#CALCULATIONS\n", "a1= a-math.degrees(math.sin(v1*math.sin(math.radians(b))/v2))\n", "w= math.cos(math.radians(a1))*v2\n", "vr= v2*math.sin(math.radians(a1))/math.sin(math.radians(a))\n", "v1= math.sqrt(v1**2+vr**2-2*v1*vr*math.cos(math.radians(a)))\n", "r= 180-math.sin(math.radians(a))*vr/v\n", "w1= v*math.cos(math.radians(r))\n", "W= v1*(w-w1)/g\n", "\n", "#RESULTS\n", "print 'a = %.2f degrees'%(a1)\n", "print ' w = %.2f ft/sec'%(w)\n", "print ' vr = %.2f ft/sec'%(vr)\n", "print ' v1 = %.2f ft/sec'%(v1)\n", "print ' w = %.2f ft/sec'%(w)\n", "print ' Work done per pound = %.2f ft-lb/lb'%(W)\n", "\n", "# Note : Answers are different because of rounding off error." ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "a = 19.32 degrees\n", " w = 37.75 ft/sec\n", " vr = 26.47 ft/sec\n", " v1 = 15.42 ft/sec\n", " w = 37.75 ft/sec\n", " Work done per pound = 25.39 ft-lb/lb\n" ] } ], "prompt_number": 2 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 9.3 Page No : 173" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "import math \n", "\n", "#initialisation of variables\n", "d= 0.5 \t#in\n", "a= 165. \t#degrees\n", "W= 7.35 \t#lb\n", "W1= 500. \t#lb\n", "t= 148. \t#sec\n", "g= 32.2 \t#ft/sec**2\n", "w= 62.3 \t#lb/ft**3\n", "\n", "#CALCULATIONS\n", "Q= W1/(t*w)\n", "v= Q*16*144/math.pi\n", "dv= v*(1-math.cos(math.radians(a)))\n", "F= dv*W1/(t*g)\n", "r= W/F\n", "k= (1-(W*t*g/(W1*v)))/math.cos(math.radians(a))\n", "\n", "#RESULTS\n", "print 'k = %.3f '%(k)\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "k = 0.788 \n" ] } ], "prompt_number": 13 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 9.4 Page No : 174" ] }, { "cell_type": "code", "collapsed": false, "input": [ "import math \n", "\n", "#initialisation of variables\n", "t= 0.25 \t#in\n", "a= 30. \t#degrees\n", "w= 480. \t#lb/ft**3\n", "h= 2. \t#in\n", "d= 0.5 \t#in\n", "l= 6. \t#in\n", "w1= 62.4 \t#lb/ft**3\n", "g= 32.2 \t#ft/sec**2\n", "\n", "#CALCULATIONS\n", "W= t*l**2*w/1728\n", "M= w1*math.pi*d**2*math.cos(math.radians(a))/(g*4*144)\n", "v= math.sqrt(W*(l/2)*math.sin(math.radians(a))/(M*2*(1./math.cos(math.radians(a)))))\n", "\n", "#RESULTS\n", "print 'Velocity of jet = %.1f ft/sec'%(v)\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Velocity of jet = 26.6 ft/sec\n" ] } ], "prompt_number": 18 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 9.5 Page No : 176" ] }, { "cell_type": "code", "collapsed": false, "input": [ "import math \n", "\n", "#initialisation of variables\n", "V= 90. \t#ft/sec\n", "a= 30. \t#degrees\n", "u= 45. \t#ft/sec\n", "\n", "#CALCULATIONS\n", "w= V*math.cos(math.radians(a))\n", "f= math.sqrt(V**2-w**2)\n", "tanb= (math.atan(math.radians(f/(w-u))))\n", "b = math.degrees(math.tan(tanb))\n", "b = math.degrees(math.atan(b))\n", "V1= math.sqrt(f**2+(u-f*1./math.tan(math.radians(b)))**2)\n", "\n", "#RESULTS\n", "print \"B = %.2f degrees\"%b\n", "print 'absolute velocity of water at the exit = %.1f ft/sec'%(V1)\n", "\n", "# rounding off error" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "B = 53.79 degrees\n", "absolute velocity of water at the exit = 46.6 ft/sec\n" ] } ], "prompt_number": 2 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 9.6 Page No : 177" ] }, { "cell_type": "code", "collapsed": false, "input": [ "import math \n", "\n", "#initialisation of variables\n", "u= 734. \t#ft/sec\n", "v= 2000. \t#ft/sec\n", "g= 32.2 \t#ft/sec**2\n", "da= 0.019 \t#kg/m**3\n", "\n", "#CALCULATIONS\n", "W= g*v/(v-u)\n", "A= W/(u*da)\n", "\n", "#RESULTS\n", "print 'Weight of the air = %.1f lb/sec'%(W)\n", "print ' Area of inlet = %.2f ft**2'%(A)\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Weight of the air = 50.9 lb/sec\n", " Area of inlet = 3.65 ft**2\n" ] } ], "prompt_number": 23 } ], "metadata": {} } ] }