{ "metadata": { "name": "", "signature": "sha256:75785fe7e68940de5df81a115443b8d5c78793053ae837735e58f86a072c05cc" }, "nbformat": 3, "nbformat_minor": 0, "worksheets": [ { "cells": [ { "cell_type": "heading", "level": 1, "metadata": {}, "source": [ "Chapter 14: Steady Incompressible Flow in Pipe and Duct System" ] }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 14.1, Page 468" ] }, { "cell_type": "code", "collapsed": false, "input": [ "from __future__ import division\n", "import math\n", "\n", "\n", " #Initializing the variables\n", "L1 = 5;\n", "L2 = 10;\n", "d = 0.1;\n", "f = 0.08;\n", "Za_Zc = 4; #difference in height between A and C \n", "g = 9.81 ;\n", "Pa = 0;\n", "Va = 0; \n", "Za_Zb = -1.5;\n", "V = 1.26;\n", "rho = 1000;\n", "\n", " #Calculations\n", "D = 1.5 + 4*f*(L1+L2)/d ; # Denominator in case of v**2 \n", "v = (2*g*Za_Zc/D)**0.5;\n", "Pb = rho*g*Za_Zb - rho*V**2/2*(1.5+4*f*L1/d);\n", "print \"Pressure in the pipe at B (kN/m2):\",round(Pb/1000,2)\n", "print \"Mean Velocity at C (m/s) :\",round(v,2)\n", "\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Pressure in the pipe at B (kN/m2): -28.61\n", "Mean Velocity at C (m/s) : 1.26\n" ] } ], "prompt_number": 1 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 14.3, Page 473" ] }, { "cell_type": "code", "collapsed": false, "input": [ "from __future__ import division\n", "import math\n", "from sympy import symbols,solve\n", "import sympy\n", "\n", "\n", " #Initializing the variables\n", "Za_Zb = 10;\n", "f = 0.008;\n", "L = 100;\n", "d1 = 0.05;\n", "g = 9.81;\n", "d2 = 0.1;\n", "\n", " #Calculations\n", "\n", "def flowRate(d):\n", " D = 1.5 + 4*f*L/d ; # Denominator in case of v1**2\n", " A = math.pi*d**2/4;\n", " v = (2*g*Za_Zb/D)**0.5;\n", " z = A*v;\n", " return z \n", "Q1 = flowRate(d1);\n", "Q2 = flowRate(d2);\n", "Q=round(Q1+Q2,4)\n", "\n", "\n", "D=symbols('D')\n", "roots=solve(241212*D**5 -3.2, D)\n", "dia=roots[0]\n", "\n", "print \"Rate flow for pipe 1 (m^3/s) :\",round(Q1,4)\n", "print \"Rate flow for pipe 2 (m^3/s) :\",round(Q2,4)\n", "print \"Combined Rate flow (m^3/s) :\",round(Q,4)\n", "print \"Diameter of single equivalent pipe (mm) :\",round(dia,3)*1000\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Rate flow for pipe 1 (m^3/s) : 0.0034\n", "Rate flow for pipe 2 (m^3/s) : 0.019\n", "Combined Rate flow (m^3/s) : 0.0224\n", "Diameter of single equivalent pipe (mm) : 106.0\n" ] } ], "prompt_number": 1 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 14.4, Page 476" ] }, { "cell_type": "code", "collapsed": false, "input": [ "from __future__ import division\n", "import math\n", "import sympy\n", "from sympy import solve,symbols\n", "\n", " #Initializing the variables\n", "Za_Zb = 16;\n", "Za_Zc = 24;\n", "f = 0.01;\n", "l1 = 120;\n", "l2 = 60;\n", "l3 = 40;\n", "d1 = 0.12;\n", "d2 = 0.075;\n", "d3 = 0.060;\n", "g = 9.81;\n", " #Calculations\n", "\n", "v1=symbols('v1')\n", "ash=solve(v1-0.3906*(g-1.25*v1**2)**0.5-0.25*(17.657-1.5*v1**2)**0.5,v1)\n", "v1=round(abs(ash[0]),2)\n", "Q1=math.pi/4*d1**2*v1\n", "\n", "v2=(g-1.25*v1**2)**0.5\n", "Q2=math.pi/4*d2**2*v2\n", "\n", "v3=(17.657-1.5*v1**2)**0.5\n", "Q3=math.pi/4*d3**2*v3\n", "\n", "print \"Flow rate in pipe 1 (m^3/s):\",round(Q1,4)\n", "print \"Flow rate in pipe 2 (m^3/s):\",round(Q2,4)\n", "print \"Flow rate in pipe 3 (m^3/s):\",round(Q3,4)\n", "print \"continuity condition satisfied as Q1=Q2+Q3\"" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Flow rate in pipe 1 (m^3/s): 0.0206\n", "Flow rate in pipe 2 (m^3/s): 0.0105\n", "Flow rate in pipe 3 (m^3/s): 0.0101\n", "continuity condition satisfied as Q1=Q2+Q3\n" ] } ], "prompt_number": 2 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 14.5, Page 480" ] }, { "cell_type": "code", "collapsed": false, "input": [ "from __future__ import division\n", "import math\n", "\n", "\n", " #Initializing the variables\n", "D = 0.3;\n", "Q = 0.8;\n", "rho = 1.2;\n", "f = 0.008;\n", "L_entry = 10;\n", "L_exit = 30;\n", "Lt = 20*D #Transition may be represented by a separation loss equivalent length of 20 * the approach duct diameter\n", "K_entry = 4;\n", "K_exit = 10\n", "l = 0.4; # length of cross section\n", "b = 0.2; # width of cross section\n", "\n", " #Calculations\n", "A = math.pi*D**2/4;\n", "Dp1 = 0.5*rho*Q**2/A**2*(K_entry + 4*f*(L_entry+Lt)/D);\n", "area = l*b;\n", "perimeter =2*(l+b);\n", "m = area/perimeter;\n", "Dp2 = 0.5*rho*Q**2/area**2*(K_exit + f*L_exit/m);\n", "Dfan = Dp1+Dp2;\n", "\n", "print \"fan Pressure input (N/m2) :\",round(Dfan,1)" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "fan Pressure input (N/m2) : 1254.6\n" ] } ], "prompt_number": 6 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 14.6, Page 482" ] }, { "cell_type": "code", "collapsed": false, "input": [ "from __future__ import division\n", "import math\n", "\n", "\n", " #Initializing the variables\n", "D = [0.15 , 0.3];\n", "rho = 1.2;\n", "f = 0.008;\n", "L_entry = 10;\n", "L_exit = 20;\n", "Lt = 20*D[1] \n", "K = 4;\n", "Q1 = 0.2;\n", "\n", " #Calculations\n", "Q2 = 4*Q1;\n", "A=[0.0,0.0]\n", "A[0] = math.pi*D[0]**2/4;\n", "A[1] = math.pi*D[1]**2/4;\n", "Dp1 = 0.5*rho*Q1**2/A[0]**2*(K + 4*f*L_entry/D[0]);\n", "Dp2 = 0.5*rho*Q2**2/A[1]**2*(4*f*(L_exit + Lt)/D[1]);\n", "Dfan = Dp1+Dp2;\n", "\n", "print \"fan Pressure input (N/m2) :\",round(Dfan,2)" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "fan Pressure input (N/m2) : 684.51\n" ] } ], "prompt_number": 7 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 14.7, Page 487" ] }, { "cell_type": "code", "collapsed": false, "input": [ "from __future__ import division\n", "import math\n", "from scipy.optimize import fsolve\n", " \n", " \n", " \n", " #Initializing the variables\n", "d = [0.1 , 0.125, 0.15, 0.1, 0.1 ]; # Corrosponding to AA1B AA2B BC CD CF\n", "l = [30 , 30 , 60, 15, 30]; # Corrosponding to AA1B AA2B BC CD CF\n", "rho = 1.2;\n", "f = 0.006;\n", "Ha = 100;\n", "Hf = 60;\n", "He = 40;\n", "K = [0.0, 0.0, 0.0, 0.0, 0.0]\n", " #Calculations\n", "for i in range(0,len(l)):\n", " K[i] = f*l[i]/(3*d[i]**5);\n", "\n", "\n", "K_ab = K[0]*K[1]/((K[0])**0.5+(K[1])**0.5)**2;\n", "K_ac = K_ab + K[2];\n", "Hc = (K_ac*Hf +K[4]*Ha/4)/(K_ac+K[4]/4);\n", "Q = ((Ha - Hc)/K_ac)**0.5;\n", "\n", "def f(n):\n", " z = He - Hc + (0.5*Q)**2 *(K[3]+(4000/n)**2);\n", " return z\n", "\n", "n = fsolve(f,1);\n", "\n", "print \"total Volume flow rate (m3/s):\",round(Q, 4)\n", "print \"Head at C (m) :\",round(Hc,2) \n", "print \"Percentage valve opening (%) :\",round(n,2)" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "total Volume flow rate (m3/s): 0.1016\n", "Head at C (m) : 75.48\n", "Percentage valve opening (%) : 38.58\n" ] } ], "prompt_number": 8 } ], "metadata": {} } ] }