{ "metadata": { "name": "", "signature": "sha256:2bebadfad4a18ede042a136ada8984e181f57290a23ad4ed8003a1f83445a447" }, "nbformat": 3, "nbformat_minor": 0, "worksheets": [ { "cells": [ { "cell_type": "heading", "level": 1, "metadata": {}, "source": [ "Chapter 25: Machine\u2013Network Interactions" ] }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 25.4, Page 893" ] }, { "cell_type": "code", "collapsed": false, "input": [ "from __future__ import division\n", "import math\n", "\n", " #Initializing the variables\n", "Pa_P1 = -200; # From previous Question\n", "Q = 1.4311 ; # From previous questions.\n", "\n", " #Calculations\n", "DpSys = Pa_P1 + 98.9*Q**2;\n", "print \"System Operating point (m^3/s):\",round(DpSys,2)" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "System Operating point (m^3/s): 2.55\n" ] } ], "prompt_number": 1 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 25.7, Page 906" ] }, { "cell_type": "code", "collapsed": false, "input": [ "from __future__ import division\n", "import math\n", "import sympy\n", "from sympy import solve,symbols\n", " \n", "\n", " #Initializing the variables\n", "Vo = 25.3; #Outlet velocity\n", "D = 10 ; # Mean hydraulic diameter\n", "f = 0.008; # friction factor\n", "X = 1000; # Length of road\n", "P = 12600; # Absorbing power\n", "Va = 300; # Tunnel air flow\n", "K1 = 0.96;\n", "K2 = 0.9;\n", "T = 590; #Thrust\n", "rho = 1.2; # Air density \n", "\n", " #Calculations\n", "alpha = (1/D)**2;\n", "A = math.pi*D**2/4; # Area of tunnel\n", "Vt = Va/A;\n", "W = Vo/Vt; #Omega\n", "E = (1-alpha*W);\n", "C = (1-alpha*W)*(1-E)**2 + E**2 - 1;\n", " # Manipulating equation 25.20;\n", "LHS = f*X*(E+1)**2/D + C + 1 ;\n", "\n", "n1 = symbols('n1')\n", "result=solve(K1*(2*((alpha*W**2 + (1-alpha)*E**2-1)+(n1-1)*(alpha*W*(W-1)-C/2)))-LHS)\n", "\n", "n=result[0]\n", "\n", "\n", " # Alternative approach using equation 25.22\n", "n2 = (rho*((4*f*X*Vt**2)/(2*D) + 1.5*Vt**2/2))*A/(K1*K2*T); \n", "Pt = round(n2)*P;\n", "\n", "print \"Number of fans required :\",round(n2)\n", "print \"Total power consumed (KW) :\",Pt/1000" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Number of fans required : 6.0\n", "Total power consumed (KW) : 75.6\n" ] } ], "prompt_number": 1 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 25.8, Page 907" ] }, { "cell_type": "code", "collapsed": false, "input": [ "from __future__ import division\n", "import math\n", "import sympy\n", "from sympy import solve,symbols\n", " #Initializing the variables\n", "f = 0.008;\n", "T = 290;\n", "L = 750;\n", "Dt = 9; # Diameter Tunnel\n", "Df = 0.63; # Diameter fan\n", "K1 = 0.98;\n", "K2 = 0.92;\n", "Vo = 27.9;\n", "n = 10;\n", "A=math.pi*Dt**2/4\n", "rho=1.2\n", "X=750\n", " #Calculations\n", "alpha = (Df/Dt)**2;\n", " # equation 25.20 becomes when E = 1 nad C = 0\n", "W=symbols('W')\n", "omega = solve(2*K1* (alpha*W**2 +(n-1)*alpha*W*(W-1)) - 4*f*L/Dt -1)\n", " \n", "\n", "for i in range(1,len(omega)): # since omega is always positive and real\n", " if omega[i]>0:\n", " w = round(omega[i],1);\n", "Vt = Vo/w;\n", "\n", "# by equation 25.22\n", "VT=(n*(K1*K2*T)/(A*(rho*((4*f*X)/(2*Dt) + 1.5/2))))**0.5\n", "print \"Tunnel Velocity (m/s) :\",round(VT,2)" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Tunnel Velocity (m/s) : 4.05\n" ] } ], "prompt_number": 2 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 25.9, Page 914" ] }, { "cell_type": "code", "collapsed": false, "input": [ "from __future__ import division\n", "import math\n", "\n", "\n", " #Initializing the variables\n", "Ws = 0.45;\n", "Ks = 3.2;\n", "H = 152;\n", "h = 0;\n", "Hatm = 10.3;\n", "Pv = 350; #vapour pressure\n", "g = 9.81;\n", "rho = 1000;\n", " \n", " #Calculations\n", "Ht1 = 152*(Ws/Ks)**(4/3); # the value of Ht1 is 11.12 and in book it is taken as 11.2 so there will be a difference in final answer\n", "Hvap = round(Pv/(rho*g),3);\n", "Z = Hatm -h -Hvap -Ht1;\n", "print \"Elevation of pump (m):\",round(Z,3)\n", " " ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Elevation of pump (m): -0.851\n" ] } ], "prompt_number": 4 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 25.11, Page 927" ] }, { "cell_type": "code", "collapsed": false, "input": [ "from __future__ import division\n", "import math\n", "import sympy\n", "from sympy import symbols,solve\n", "import numpy as np\n", " \n", "\n", " #Initializing the variables\n", "Co = 0;\n", "Qc = 0.0024;\n", "V = 5400;\n", "c = 10;\n", " #Calculations\n", "#####--------------------PART(A)-----------------#######\n", "n1=symbols('n1')\n", "def partA(n1):\n", " Ci = 10;\n", " # t = infinity so e^(-nt) = 0\n", " Q=10000*Qc/(c-Co)\n", " n1 = Q*3600/V; \n", " return n1\n", "ans=partA(n1)\n", "\n", "print \"Part(A) : number of air changes per hour if the garage is in continuous use and the maximum permissible concentration of carbon monoxide is 0.1 per cent. :\",ans,\"\\n\"\n", "\n", "#####--------------------PART(B)-----------------#######\n", "n=symbols('n')\n", "def partB(n):\n", " Ci = 0; \n", " n=[1.5,1.2,0.9,1.0] \n", " t=1 # time in hours\n", " error=[]\n", " mini=100\n", " ans=0\n", " for i in range(4): \n", " Q = V/3600; \n", " A = 10000*Qc/Q; # as Co=0 \n", " error.append(abs((A*(1-math.e**(-n[i]*t))/c)-n[i]));\n", " if(error[i]