{ "metadata": { "name": "", "signature": "sha256:24438326f2aac267ced1e2e3aa21e094819eefb50d5f8862608b62208400992d" }, "nbformat": 3, "nbformat_minor": 0, "worksheets": [ { "cells": [ { "cell_type": "heading", "level": 1, "metadata": {}, "source": [ "Chapter 12: Incompressible Flow around a Body" ] }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 12.1, Page 399" ] }, { "cell_type": "code", "collapsed": false, "input": [ "from __future__ import division\n", "import math\n", "\n", "\n", " #Initializing the variables\n", "x =35;\n", "T = 50;\n", "m = 1;\n", "g =9.81;\n", "rho = 1.2;\n", "A = 1.2;\n", "U0 = 40*1000/3600; # Velocity in m/s\n", "\n", " #Calculations\n", "L = T*math.sin(math.radians(x))+m*g;\n", "D =T*math.cos(math.radians(x));\n", "Cl = 2*L/(rho*U0**2*A);\n", "Cd = 2*D/(rho*U0**2*A); \n", "\n", "print \"Lift Coefficient :\",round(Cl,3)\n", "print \"Drag Coefficient :\",round(Cd,3)" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Lift Coefficient : 0.433\n", "Drag Coefficient : 0.461\n" ] } ], "prompt_number": 1 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 12.2, Page 406" ] }, { "cell_type": "code", "collapsed": false, "input": [ "from __future__ import division\n", "import math\n", "\n", "\n", " #Initializing the variables\n", "Vp =12;\n", "lp = 40;\n", "lm = 1;\n", "As = 2500;\n", "Dm = 32;\n", "rhoP = 1025;\n", "rhoM = 1000;\n", "Ap = As;\n", "\n", " #Calculations\n", "Am = As/40**2;\n", "Vm = round(Vp*(lm/lp)**0.5,2);\n", "Dfm = round(3.7*Vm**1.95*Am,1);\n", "Rm = Dm - Dfm;\n", "Rp = Rm *(rhoP/rhoM)*(lp/lm)**2*(Vp/Vm)**2;\n", "Dfp = 2.9*Vp**1.8*Ap;\n", "Dp = Rp + Dfp;\n", "\n", "print \"Expected total resistance (kN) :\",round(Dp/1000,2)" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Expected total resistance (kN) : 1407.07\n" ] } ], "prompt_number": 2 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 12.3, Page 410" ] }, { "cell_type": "code", "collapsed": false, "input": [ "from __future__ import division\n", "import math\n", "\n", "\n", " #Initializing the variables\n", "U0 = 80*1000/3600;\n", "d = 0.02;\n", "rho =1.2;\n", "mu = 1.7*10**-5;\n", "A = 0.02*500; # Projected area of wire\n", "N = 20; # No of cables\n", "\n", " #Calculations\n", "Re = rho*U0*d/mu;\n", "Cd = 1.2 # From figure 12.10 for given Re; \n", "D = 0.5*rho*Cd*A*U0**2\n", "F = N*D; \n", "f = 0.198*(U0/d)*(1-19.7/Re);\n", "\n", "print \"Total force on tower (kN) :\",round(F/1000,2)\n", "print \"Frequency (Hz) :\",round(f,1)" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Total force on tower (kN) : 71.11\n", "Frequency (Hz) : 219.9\n" ] } ], "prompt_number": 3 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 12.4, Page 415" ] }, { "cell_type": "code", "collapsed": false, "input": [ "from __future__ import division\n", "import math\n", "\n", "\n", " #Initializing the variables\n", "mu = 0.03;\n", "d = 10**-3;\n", "rhoP = 1.1*10**3;\n", "g = 9.81;\n", "rho0 = 0.9*10**3;\n", " #Calculations\n", "B = 18*mu/(d**2*rhoP);\n", "t = round(4.60/B,4);\n", "Vt = round(d**2*(rhoP - rho0)*g/(18*mu),5);\n", "Re = rho0*Vt*d/mu;\n", "\n", "print \"Time taken by the particle take to reach 99 per cent of its terminal velocity (s):\",t\n", "print \"\\nReynolds No corrosponding to the velocity :\",Re" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Time taken by the particle take to reach 99 per cent of its terminal velocity (s): 0.0094\n", "\n", "Reynolds No corrosponding to the velocity : 0.1089\n" ] } ], "prompt_number": 4 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 12.5, Page 417" ] }, { "cell_type": "code", "collapsed": false, "input": [ "from __future__ import division\n", "import math\n", "\n", "\n", " #Initializing the variables\n", "muO = 0.0027;\n", "Vt = 3*10**-3;\n", "rhoW = 1000;\n", "rhoP = 2.4*rhoW;\n", "rhoO = 0.9*rhoW;\n", "g = 9.81;\n", "muA = 1.7*10**-5;\n", "rhoA = 1.3;\n", "\n", " #Calculations\n", "d = (18*muO*Vt/(rhoP-rhoO)/g)**0.5;\n", "Re = Vt*d*rhoO/muO;\n", "\n", " #Movement of particle in upward direction\n", "if(Re < 1):\n", " v = 0.5;\n", " \n", " Re=5; # from fig 12.15\n", " vt = muA*Re/(rhoA*d);\n", " u = vt+v;\n", " print \"Velocity of air stream blowing vertically up (m/s) :\",round(u,3) \n", "else:\n", " print \"strokes law is not valid\"" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Velocity of air stream blowing vertically up (m/s) : 1.157\n" ] } ], "prompt_number": 5 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 12.6, Page 429" ] }, { "cell_type": "code", "collapsed": false, "input": [ "from __future__ import division\n", "import math\n", "\n", "\n", " #Initializing the variables\n", "c = 2;\n", "s = 10;\n", "rho = 5.33;\n", "rho_ellip = 1.2;\n", "D = 400;\n", "L = 45000;\n", "scale = 20;\n", "U_windTunnel = 500;\n", "U_proto = 400*1000/3600;\n", "\n", " #Calculations\n", "A = c*s;\n", "U_model = U_windTunnel/scale;\n", "Cd = D/(0.5*rho*U_model**2*A);\n", "Cl = L/(0.5*rho_ellip*U_proto**2*A); # Considering elliptical Lift model\n", "Cdi = Cl**2/(math.pi*s/c); # Aspect Ratio = s/c \n", "Cdt = Cd + Cdi;\n", "Dw = 0.5*Cdt*rho_ellip*U_proto**2*A;\n", "print \"Total drag on full sized wing (kN) :\",round(Dw/1000,2)" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Total drag on full sized wing (kN) : 2.65\n" ] } ], "prompt_number": 6 } ], "metadata": {} } ] }