{ "metadata": { "name": "" }, "nbformat": 3, "nbformat_minor": 0, "worksheets": [ { "cells": [ { "cell_type": "heading", "level": 1, "metadata": {}, "source": [ "Chapter 9 : Similarity and Dimensional Analysis" ] }, { "cell_type": "heading", "level": 3, "metadata": {}, "source": [ "Example 9.1.1 page no : 219" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "#initialisation of variables\n", "\n", "pm= 1.6 \t\t\t#lb/ft**3\n", "vm= 6.2*10**-6 \t\t#ft**2/sec\n", "R= 1.8 \t\t\t #lbf\n", "um= 100. \t\t\t#ft/sec\n", "p= 64. \t\t\t #lb/ft**3\n", "v= 1.7*10**-5 \t #ft^2/sec\n", "lm_by_l= 1/10. \t\t#ft\n", "\t\t\t\n", "#CALCULATIONS\n", "u= (um*lm_by_l*v)/vm\n", "u_knot= ((um*lm_by_l*v)/vm)/1.98 #knot\n", "F_by_Fm = (p/pm)*(1/lm_by_l)**2*(u/um)**2\n", "F= F_by_Fm*R\n", "\t\t\t\n", "#RESULTS\n", "print ' speed of torpedo in sea water = %.1f knot'%u_knot\n", "print ' resistance= %.f lbf '%(F)\n", "print (1/lm_by_l)**2\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ " speed of torpedo in sea water = 13.8 knot\n", " resistance= 541 lbf \n", "100.0\n" ] } ], "prompt_number": 7 }, { "cell_type": "heading", "level": 3, "metadata": {}, "source": [ "Example 9.2.1 page no : 222" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "#initialisation of variables\n", "import math \n", "\n", "S= 5. \t\t\t#ft\n", "F= 70. \t\t\t#lbf\n", "B= 4. \t\t\t#degrees\n", "l= 1. \t\t\t#ft\n", "d= 0.002378 \t\t\t#slug/ft**3\n", "u= 120. \t\t\t#ft/sec\n", "\t\t\t\n", "#CALCULATIONS\n", "L= F*math.cos(math.radians(B))\n", "D=F*math.sin(math.radians(B))\n", "S1= S*l\n", "p= 0.5*d*u**2\n", "Cl= L/(p*S1)\n", "Cd= D/(p*S1)\n", "\t\t\t\n", "#RESULTS\n", "print ' coefficient of lift= %.2f'%(Cl)\n", "print ' coefficient of drag= %.4f'%(Cd)\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ " coefficient of lift= 0.82\n", " coefficient of drag= 0.0570\n" ] } ], "prompt_number": 8 }, { "cell_type": "heading", "level": 3, "metadata": {}, "source": [ "Example 9.2.2 page no : 225" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "#initialisation of variables\n", "import math \n", "\n", "A= 600. \t\t\t#ft**2\n", "W= 40. \t\t\t#lbf/ft**2\n", "n= 75. \t\t\t#percent\n", "r= 10.\n", "v= 300. \t\t\t#miles/hour\n", "\t\t\t\n", "#CALCULATIONS\n", "L= W*A\n", "D= L/r\n", "P= D*v*5280./(60.*33000)\n", "hp= P*100./n\n", "\t\t\t\n", "#RESULTS\n", "print ' brake horse-power of the engines= %.f h.p'%(hp)\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ " brake horse-power of the engines= 2560 h.p\n" ] } ], "prompt_number": 9 }, { "cell_type": "heading", "level": 3, "metadata": {}, "source": [ "Example 9.2.4 page no : 226" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "#initialisation of variables\n", "W = 22400 # lbf\n", "p = 0.002378 # slug/ft^3\n", "S = 500. # ft**2\n", "b = 398. \n", "a = 293\n", "D1 = 1530. # lbf\n", "U = 200. \n", "\n", "\n", "# Calculation\n", "#Part a\n", "U1 = round((2*W/(p*S)),-2)**(1./2) * (b/a)**(1./4)\n", "P1 = round((D1 * U1)/550)\n", "\n", "#Part b\n", "Umph = U1*0.681818 # ft/sec to m.p.h\n", "D = round(round((D1/2)*((U/Umph)**2 + (Umph/U)**2),1))\n", "P = round(D*U*5280./(60*33000),-1)\n", "U = .76 * U1\n", "D = (D1/2.)*((U/Umph)**2 + (Umph/U)**2)\n", "power = round((D * U)*5280./(60*33000),-2)\n", "\n", "# Part c\n", "min_power = .76 * U\n", "# Results\n", "print \"a)Power expended for minumum drag is = %.1f h.p.\"%P1\n", "print \" Speed for minimum power is U = %.1f m.p.h\"%U\n", "print \"b)Drag for minimum power is = %.0f lbf\"%D\n", "print \" The minimum power is = %.0f h.p.\"%power\n", "print \"c) Speed for minimum power is U = %.1f m.p.h\"%min_power\n", "print \"Answers in book are wrong. Please calculate manually.\"" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "a)Power expended for minumum drag is = 583.0 h.p.\n", " Speed for minimum power is U = 159.3 m.p.h\n", "b)Drag for minimum power is = 1566 lbf\n", " The minimum power is = 700 h.p.\n", "c) Speed for minimum power is U = 121.1 m.p.h\n", "Answers in book are wrong. Please calculate manually.\n" ] } ], "prompt_number": 1 }, { "cell_type": "heading", "level": 3, "metadata": {}, "source": [ "Example 9.3.1 page no :231" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "#initialisation of variables\n", "\n", "va= 0.2\n", "r= 1./1.25\n", "r1= 1./50\n", "P= 20. \t\t\t#atm\n", "v= 400. \t\t\t#m.p.h\n", "\t\t\t\n", "#CALCULATIONS\n", "Um= v*va/(P*r*r1)\n", "\t\t\t\n", "#RESULTS\n", "print ' Speed of air= %.f m.p.h'%(Um)\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ " Speed of air= 250 m.p.h\n" ] } ], "prompt_number": 17 }, { "cell_type": "heading", "level": 3, "metadata": {}, "source": [ "Example 9.4.1 page no : 234" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "import math \n", "#initialisation of variables\n", "\n", "\n", "U= 30. \t\t\t#ft/sec\n", "g= 32.2 \t\t\t#ft/sec**2\n", "l= 500.\t\t\t#ft\n", "r= 1./25\n", "\t\t\t\n", "#CALCULATIONS\n", "F=(U**2./(l*g))\n", "R= math.sqrt(r)\n", "Um= U*R\n", "\t\t\t\n", "#RESULTS\n", "print ' Froude number= %.4f '%(F)\n", "print ' speed= %.f ft/sec'%(Um)\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ " Froude number= 0.0559 \n", " speed= 6 ft/sec\n" ] } ], "prompt_number": 48 }, { "cell_type": "heading", "level": 3, "metadata": {}, "source": [ "Example 9.4.2 pageno : 234" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "import math \n", "#initialisation of variables\n", "\n", "R1= 9.5 \t\t\t#lbf\n", "f1= 0.01\n", "S1= 22. \t\t\t#ft**2\n", "U1= 5.3\n", "n= 1.825\n", "l= 540.\t\t\t#ft\n", "l1= 15. \t\t\t#ft\n", "C= 0.0087\t\t\t#lbf/ft**2\n", "\t\t\t\n", "#CALCULATIONS\n", "Rr1= round(R1-f1*S1*U1**n,1)\n", "U= U1*math.sqrt(l/l1)\n", "r= (l/l1)**3.\n", "Rr= round(r*Rr1,-3)\n", "Rf= C*(l/l1)**2*S1*U**n\n", "R= Rr+Rf\n", "P= R*U*1.69/550.\n", "\n", "\n", "#RESULTS\n", "print ' propulsive power= %.f h.p'%(P)\n", "print 'Answer in book is wrong.'" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ " propulsive power= 35755 h.p\n", "Answer in book is wrong.\n" ] } ], "prompt_number": 58 }, { "cell_type": "heading", "level": 3, "metadata": {}, "source": [ "Example 9.5.1 pageno : 237" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "import math \n", "#initialisation of variables\n", "\n", "s= 20. \t\t\t#ft\n", "u= 10. \t\t\t#ft/sec\n", "t= 1. \t\t\t#sec\n", "\t\t\t\n", "#CALCULATIONS\n", "r= s/u*t\n", "a= r*u/t\n", "\t\t\t\n", "#RESULTS\n", "print ' constant accelaration= %.f ft/sec**2'%(a)\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ " constant accelaration= 20 ft/sec**2\n" ] } ], "prompt_number": 18 }, { "cell_type": "heading", "level": 3, "metadata": {}, "source": [ "Example 9.5.2 pageno : 237" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "#initialisation of variables\n", "a= 20. \t\t\t#ft/sec**2\n", "s= 20.\t\t\t#ft\n", "u= 10. \t\t\t#ft/sec\n", "\t\t\t\n", "#CALCULATIONS\n", "P= a*s/u**2.\n", "t= s*2/(u*P)\n", "\t\t\t\n", "#RESULTS\n", "print ' time taken= %.f sec'%(t)\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ " time taken= 1 sec\n" ] } ], "prompt_number": 60 }, { "cell_type": "heading", "level": 3, "metadata": {}, "source": [ "Example 9.6.1 page no : 242\n" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "#initialisation of variables\n", "\n", "s= 0.8\n", "l= 1.\t\t\t#ft\n", "r= 8.\n", "\t\t\t\n", "#CALCULATIONS\n", "Hw= (s/r)**(2./3)*l\n", "Qw= 1.5*Hw**(2.5)\n", "R= (1./Hw)**2.5\n", "Q= Qw*R\n", "\t\t\t\n", "#RESULTS\n", "print ' depth of water= %.3f ft'%(Hw)\n", "print ' rate of flow of fluid= %.1f ft**3/sec'%(Q)\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ " depth of water= 0.215 ft\n", " rate of flow of fluid= 1.5 ft**3/sec\n" ] } ], "prompt_number": 61 }, { "cell_type": "heading", "level": 3, "metadata": {}, "source": [ "Example 9.6.3 pageno : 244" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "#initialisation of variables\n", "\n", "Q1= 140. \t\t\t#gallons\n", "h= 3. \t\t\t#in\n", "r= 16.\n", "\t\t\t\n", "#CALCULATIONS\n", "H= h*r/12.\n", "Q2= round(Q1*H**5.,-3)\n", "\t\t\t\n", "#RESULTS\n", "print ' corresponding head over the full-scale wier= %.f ft'%(H)\n", "print ' discharge over the latter= %.f gal/min'%(Q2)\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ " corresponding head over the full-scale wier= 4 ft\n", " discharge over the latter= 143000 gal/min\n" ] } ], "prompt_number": 63 }, { "cell_type": "heading", "level": 3, "metadata": {}, "source": [ "Example 9.7.1 page no: 248" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "#initialisation of variables\n", "\n", "r= 0.448\n", "R= 0.868\n", "r1= 0.152\n", "R1= 0.807\n", "\t\t\t\n", "#CALCULATIONS\n", "P= R**3./r**2.\n", "U= R/r\n", "P1= R1**3./r1**2.\n", "U1= R1/r1\n", "\t\t\t\n", "#RESULTS\n", "print ' power ratio in case 1= %.2f '%(P)\n", "print ' velocity ratio in case 1= %.2f '%(U)\n", "print ' power ratio in case 2= %.2f '%(P1)\n", "print ' velocity ratio in case 2= %.1f '%(U1)\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ " power ratio in case 1= 3.26 \n", " velocity ratio in case 1= 1.94 \n", " power ratio in case 2= 22.75 \n", " velocity ratio in case 2= 5.3 \n" ] } ], "prompt_number": 64 }, { "cell_type": "heading", "level": 3, "metadata": {}, "source": [ "Example 9.7.2 page no : 249" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "import math \n", "\n", "#initialisation of variables\n", "w= 1. \t\t\t#gf/cm**3\n", "Ss= 7.8\n", "Sl= 0.9\n", "D= 1. \t\t\t#cm\n", "D1= 0.1 \t\t\t#cm\n", "g= 981. \t\t\t#cm/sec**2\n", "\t\t\t\n", "#CALCULATIONS\n", "F= w*(Ss-Sl)*4.*math.pi*D**3./(3.*8000)\n", "v= F*g/(3*math.pi*D1*2.)\n", "\t\t\t\n", "#RESULTS\n", "print ' coefficient of viscosity= %.2f poise'%(v)\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ " coefficient of viscosity= 1.88 poise\n" ] } ], "prompt_number": 65 }, { "cell_type": "heading", "level": 3, "metadata": {}, "source": [ "Example 9.7.4 page no : 251" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "#initialisation of variables\n", "\n", "T= 15. \t\t\t#C\n", "T1= -44. \t\t\t#C\n", "P= 24. \t\t\t#atm\n", "s= 0.374\n", "m= 6. \t\t\t#tonf\n", "\t\t\t\n", "#CALCULATIONS\n", "r= ((T+273.)/(T1+273))**0.75\n", "R= P/s\n", "R1= r**2./R\n", "F= R1*m*2240.\n", "\t\t\t\n", "#RESULTS\n", "print ' lift force= %.1f lbf'%(F)\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ " lift force= 295.4 lbf\n" ] } ], "prompt_number": 66 }, { "cell_type": "heading", "level": 3, "metadata": {}, "source": [ "Example 9.7.5 page no : 253\n" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "#initialisation of variables\n", "\n", "u= 80. \t\t\t#ft/sec\n", "n= 62.\n", "r= 1./4\n", "v= 11. \t\t\t#ft**3\n", "w= 62.3\t\t\t#lbf/ft**3\n", "p= 2. \t\t\t#lbf/in**2\n", "\t\t\t\n", "#CALCULATIONS\n", "uw= u*n/(r*v*w)\n", "R= v*w*(uw/u)**2.\n", "P= r**2.*p/R\n", "\t\t\t\n", "#RESULTS\n", "print ' water velocity= %.f ft/sec'%(uw)\n", "print ' pressure drop= %.5f lbf/in**2 per ft'%(P)\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ " water velocity= 29 ft/sec\n", " pressure drop= 0.00139 lbf/in**2 per ft\n" ] } ], "prompt_number": 67 }, { "cell_type": "heading", "level": 3, "metadata": {}, "source": [ "Example 9.8.3 pageno : 259" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "#initialisation of variables\n", "\n", "N= 1800. \t\t\t#rev/min\n", "Vm= 60. \t\t\t#mile/hour\n", "V= 300. \t\t\t#mile/hour\n", "r= 10.\n", "\t\t\t\n", "#CALCULATIONS\n", "Nm= N*Vm*r/V\n", "\t\t\t\n", "#RESULTS\n", "print ' rotary speed= %.f rev/min'%(Nm)\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ " rotary speed= 3600 rev/min\n" ] } ], "prompt_number": 68 } ], "metadata": {} } ] }