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|
{
"metadata": {
"name": ""
},
"nbformat": 3,
"nbformat_minor": 0,
"worksheets": [
{
"cells": [
{
"cell_type": "heading",
"level": 1,
"metadata": {},
"source": [
"Chapter 10 : Fluid flow in ducts"
]
},
{
"cell_type": "heading",
"level": 3,
"metadata": {},
"source": [
"Example 10.1 - Page No :405\n"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"# Compute the viscosity in CP.\n",
"\n",
"import math \n",
"\n",
"# Variables\n",
"T = 30.; \t\t\t #[degC] - temperature\n",
"d = 8.265*10**-4; \t\t\t #[m] - diameter of the capillary viscometer\n",
"deltapbyL = -0.9364; \t\t #[psi/ft] - pressure drop per unit length\n",
"\n",
"# Calculations\n",
"deltapbyL = deltapbyL*(2.2631*10**4); \t\t\t #[kg/m**2*sec**2] - pressure drop per unit length\n",
"Q = 28.36*(10**-6)*(1./60);\n",
"p = (0.88412-(0.92248*10**-3)*T)*10**3; \t\t\t #[kg/m**3] - density\n",
"s = (math.pi*(d**2))/4.;\n",
"U = Q/s;\n",
"tauw = (d/4.)*(-deltapbyL);\n",
"shearrate = (8*U)/d;\n",
"mu = tauw/(shearrate);\n",
"\n",
"# Results\n",
"print \" The viscosity is mu = %.3ef kg/m*sec = %.4f cP\"%(mu,mu*10**3);\n",
"print \" Finally, it is important to check the reynolds number to make sure the above equation applies\"\n",
"Nre = (d*U*p)/(mu);\n",
"print \" Nre = %d\"%Nre\n",
"print \" The flow is well within the laminar region and therefore the above equation applies\";\n",
"\n"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
" The viscosity is mu = 5.135e-04f kg/m*sec = 0.5135 cP\n",
" Finally, it is important to check the reynolds number to make sure the above equation applies\n",
" Nre = 1214\n",
" The flow is well within the laminar region and therefore the above equation applies\n"
]
}
],
"prompt_number": 1
},
{
"cell_type": "heading",
"level": 3,
"metadata": {},
"source": [
"Example 10.2 - Page No :407\n"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"# Compute the pressure drop for the same 0.032%in \n",
"\n",
"# Variables\n",
"Nreold = 1214.;\n",
"Uold = 0.8810;\n",
"Nre = 13700.;\n",
"U = Uold*(Nre/Nreold);\n",
"Lbyd = 744.;\n",
"T = 30.; \n",
"\n",
"# Calculations\n",
"# umath.sing the newton raphson method to calculate the value of f from the equation - 1/(f**(1/2)) = 4*math.log(Nre*(f**(1/2)))-0.4\n",
"f = 0.007119;\n",
"p = (0.88412-(0.92248*10**-3)*T)*10**3; \t\t\t #[kg/m**3] - density\n",
"tauw = (1./2)*p*(U**2)*f;\n",
"deltap = tauw*(4.)*(Lbyd);\n",
"d = 0.03254/12; \t\t\t #[ft]\n",
"L = Lbyd*d;\n",
"\n",
"# Results\n",
"print \" Pressure drop is -deltap = %.3e N/m**2 = %.1f kpa = 130 psi\"%(deltap,deltap*10**-3); \n",
"print \" A pressure drop of 130 psi on a tube of length of %.3f ft is high and \\\n",
"\\nshows the impracticality of flows at high reynolds number in smaller tubes\"%(L);\n",
"\n",
"# Answer may vary because of rounding error."
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
" Pressure drop is -deltap = 8.968e+05 N/m**2 = 896.8 kpa = 130 psi\n",
" A pressure drop of 130 psi on a tube of length of 2.017 ft is high and \n",
"shows the impracticality of flows at high reynolds number in smaller tubes\n"
]
}
],
"prompt_number": 10
},
{
"cell_type": "heading",
"level": 3,
"metadata": {},
"source": [
"Example 10.3 - Page No :414\n"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"# Calculate the pressure drop in a pipe of 6-cm inside diameter for water flowing\n",
"\n",
"# Variables\n",
"u = 1./60; \t\t\t #[m/sec] - velocity\n",
"p = 1000.; \t\t\t #[kg/m**3] - density\n",
"mu = 1*10.**-3; \t\t #[kg/m*sec] - vismath.cosity\n",
"d = 6*10.**-2; \t\t #[m] - insid_e diameter of tube\n",
"L = 300.; \t\t\t #[m] - length of the tube\n",
"\n",
"# Calculations\n",
"Nre = (d*u*p)/(mu);\n",
"f = 16./Nre;\n",
"deltap = (4.*f)*(L/d)*((p*(u**2))/2.);\n",
"\n",
"# Results\n",
"print \"Nre = \",Nre,\"therefore the flow is laminar\"\n",
"print \"f = \" , f\n",
"print \"Pressure drop -delta P = %.2f N/m**2 = %.4f kPa = %.3e psi\"%(deltap,deltap*10**-3,deltap*1.453*10**-4);\n",
"\n"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"Nre = 1000.0 therefore the flow is laminar\n",
"f = 0.016\n",
"Pressure drop -delta P = 44.44 N/m**2 = 0.0444 kPa = 6.458e-03 psi\n"
]
}
],
"prompt_number": 2
},
{
"cell_type": "heading",
"level": 3,
"metadata": {},
"source": [
"Example 10.4 - Page No :415\n"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"'''\n",
"Repeat the previous example for Reynolds numbers of 10 000 and\n",
"100 000. Contrast smooth pipe with commercial steel pipe and cast iron pipe.\n",
"'''\n",
"\n",
"from numpy import *\n",
"\n",
"# Variables\n",
"# given\n",
"d = 6.*10**-2; \t\t\t #[m] - insid_e diameter of tube\n",
"p = 1000.; \t\t\t #[kg/m**3] - density\n",
"# for smooth pipe\n",
"Nre = array([10**4, 10**5]);\n",
"f = array([0.0076, 0.0045]);\n",
"mu = 10.**-3; \t\t\t #[kg/m**2*s]\n",
"U = (Nre*mu)/(d*p);\n",
"L = 300.; \t\t\t #[m] - length of the tube\n",
"\n",
"# Calculations\n",
"deltap = zeros(2)\n",
"for i in range(2):\n",
" deltap[i] = (4*f[i])*(L/d)*((p*(U[i]**2))/2.);\n",
"\n",
"\n",
"# Results\n",
"print \"for smooth pipe\"\n",
"print \" Nre f -deltap\";\n",
"print \" %6.0f %6.4f %6.3f\"%(Nre[0],f[0],deltap[0])\n",
"print \" %6.0f %6.4f %6.3f\"%(Nre[1],f[1],deltap[1])\n",
"\n",
"# for commercial steel\n",
"Nre = array([10**4, 10**5]);\n",
"f = array([0.008 ,0.0053]);\n",
"U = (Nre*mu)/(d*p);\n",
"L = 300.; \t\t\t #[m] - length of the tube\n",
"for i in range(2):\n",
" deltap[i] = (4*f[i])*(L/d)*((p*(U[i]**2))/2);\n",
"\n",
"print \"\\nfor commercial steel pipe\"\n",
"print \" Nre f -deltap\";\n",
"print \" %6.0f %6.4f %6.3f\"%(Nre[0],f[0],deltap[0])\n",
"print \" %6.0f %6.4f %6.3f\"%(Nre[1],f[1],deltap[1])\n",
"\n",
"# for cast iron pipe\n",
"Nre = array([10**4 ,10**5]);\n",
"f = array([0.009 ,0.0073]);\n",
"U = (Nre*mu)/(d*p);\n",
"L = 300.; \t\t\t #[m] - length of the tube\n",
"for i in range(2):\n",
" deltap[i] = (4*f[i])*(L/d)*((p*(U[i]**2))/2);\n",
"\n",
"print \"\\nfor cast iron pipe\"\n",
"print \" Nre f -deltap\";\n",
"print \" %6.0f %6.4f %6.3f\"%(Nre[0],f[0],deltap[0])\n",
"print \" %6.0f %6.4f %6.3f\"%(Nre[1],f[1],deltap[1])"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"for smooth pipe\n",
" Nre f -deltap\n",
" 10000 0.0076 2111.111\n",
" 100000 0.0045 125000.000\n",
"\n",
"for commercial steel pipe\n",
" Nre f -deltap\n",
" 10000 0.0080 2222.222\n",
" 100000 0.0053 147222.222\n",
"\n",
"for cast iron pipe\n",
" Nre f -deltap\n",
" 10000 0.0090 2500.000\n",
" 100000 0.0073 202777.778\n"
]
}
],
"prompt_number": 24
},
{
"cell_type": "heading",
"level": 3,
"metadata": {},
"source": [
"Example 10.5 - Page No :417\n"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"# Find, the maximum flow velocity by trial and error.\n",
"\n",
"# Variables\n",
"L = 300.; \t\t\t #[m] - length of pipe\n",
"d = 0.06; \t\t\t #[m] - insid_e diameter\n",
"deltap = 147.*10**3; \t\t #[Pa] - pressure the pump can supply\n",
"ebyd = 0.000762; \t\t\t # relative roughness\n",
"p = 1000.; \t\t\t #[kg/m**3] - density\n",
"mu = 1.*10**-3; \t\t\t #[kg/m*sec] - viscosity\n",
"tauw = (d*(deltap))/(4.*L);\n",
"\n",
"# using the hit and trial method for estimation of flow velocity\n",
"# Calculations\n",
"# let \n",
"f = 0.005;\n",
"U = ((2*tauw)/(p*f))**(1./2);\n",
"Nre = (d*U*p)/mu;\n",
"\n",
"# from the graph value of f at the above calculated reynolds no. and the given relative roughness(e/d)\n",
"f = 0.0054;\n",
"U = ((2*tauw)/(p*f))**(1./2);\n",
"Nre = (d*U*p)/mu;\n",
"\t\t\t # from the graph value of f at the above calculated reynolds no. and the given relative roughness(e/d)\n",
"f = 0.0053;\n",
"U = ((2*tauw)/(p*f))**(1./2);\n",
"Nre = (d*U*p)/mu;\n",
"\n",
"# from the graph value of f at the above calculated reynolds no. and the given relative roughness(e/d)\n",
"f = 0.0053;\n",
"# At this point the value of f is deemed unchanged from the last iteration .Hence, the values obtained after the third iteration are the converged values\n",
"\n",
"# Results\n",
"print \" The maximum flow velocity is U = %f m/sec\"%(U);\n",
"\n",
"# Answer may vary because of rounding error."
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
" The maximum flow velocity is U = 1.665408 m/sec\n"
]
}
],
"prompt_number": 26
},
{
"cell_type": "heading",
"level": 3,
"metadata": {},
"source": [
"Example 10.6 - Page No :419\n"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"# Repeat Example 10.5 using the von Karman plot, Fig. 10.5.\n",
"\n",
"# Variables\n",
"L = 300.; \t\t\t #[m] - length of pipe\n",
"d = 0.06; \t\t\t #[m] - insid_e diameter\n",
"deltap = 147.*10**3; \t #[Pa] - pressure the pump can supply\n",
"ebyd = 0.000762; \t\t # relative roughness\n",
"p = 1000.; \t\t\t #[kg/m**3] - density\n",
"\n",
"# Calculations\n",
"mu = 1*10**-3; \t\t\t #[kg/m*sec] - viscosity\n",
"Nvk = ((d*p)/mu)*((d*(deltap))/(2*L*p))**(1./2);\n",
"\n",
"# From the fig at given von karman no and relative roughness the value of f is-\n",
"f = 0.0055;\n",
"Nre = Nvk/(f**(1./2))\n",
"U = (Nre*mu)/(d*p);\n",
"\n",
"# Results\n",
"print \"von karman no. %.0f\"%Nvk\n",
"print \" Average velocity = %.2f m/sec\"%(U);\n"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"von karman no. 7275\n",
" Average velocity = 1.63 m/sec\n"
]
}
],
"prompt_number": 3
},
{
"cell_type": "heading",
"level": 3,
"metadata": {},
"source": [
"Example 10.7 - Page No :422\n"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"# estimate the pressure drop in a 0.06-m ID commercial steel pipe at Reynolds numbers of 104 and 16\n",
"\n",
"# Variables\n",
"L = 300.; \t\t\t #[m] - length of pipe\n",
"d = 0.06; \t\t\t #[m] - insid_e diameter\n",
"p = 1000.; \t\t\t #[kg/m**3] - density\n",
"mu = 1.*10**-3; \t\t\t #[kg/m*sec] - vismath.cosity\n",
"\n",
"# Calculations\n",
"Nre = array([10.**4, 10.**5]);\n",
"U = (Nre*mu)/(d*p);\n",
"velocityhead = (U**2)/2.;\n",
"N = (L/d)/45.; \t\t\t # no of velocity heads\n",
"deltap = p*N*(velocityhead);\n",
"\n",
"# Results\n",
"for i in range(2):\n",
" print \"Nre = \",Nre[i]\n",
" print \" velocity head = %.5f m**2/sec**2\"%(velocityhead[i]);\n",
" print \" -deltap = %.3f kPa = %.3f psi\"%(deltap[i]*10**-3,deltap[i]*1.453*10**-4);\n"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"Nre = 10000.0\n",
" velocity head = 0.01389 m**2/sec**2\n",
" -deltap = 1.543 kPa = 0.224 psi\n",
"Nre = 100000.0\n",
" velocity head = 1.38889 m**2/sec**2\n",
" -deltap = 154.321 kPa = 22.423 psi\n"
]
}
],
"prompt_number": 32
},
{
"cell_type": "heading",
"level": 3,
"metadata": {},
"source": [
"Example 10.8 - Page No :439\n"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"# Compute p, by (a) the equivalent length method and (b) the loss coefficient method.\n",
"\n",
"# Variables\n",
"mu = 6.72*10**-4; \t\t #[lb/ft*sec] - vismath.cosity\n",
"p = 62.4; \t\t\t #[lb/ft**3] - density\n",
"S = 0.03322; \t\t\t #[ft**2] - flow area\n",
"d = 0.206; \t\t\t #[ft]\n",
"e = 1.5*10**-4; \t\t # absolute roughness for steel pipe\n",
"ebyd = e/d;\n",
"Nre = 10.**5;\n",
"\n",
"# friction factor as read from fig in book for the given reynolds no. and relative roughness is-\n",
"f = 0.0053;\n",
"U = (Nre*mu)/(p*d);\n",
"Q = U*S;\n",
"gc = 32.174;\n",
"\n",
"# Calculations\n",
"# (a) equivalent length method\n",
"deltapbyL = f*(4/d)*(p*(U**2))*(1/(2*gc))*(6.93*10**-3);\n",
"\n",
"# using L = Lpipe+Lfittings+Lloss;\n",
"Lfittings = 2342.1*d;\n",
"kc = 0.50; \t\t\t # due to contraction loss\n",
"ke = 1.; \t\t\t # due to enlargement loss\n",
"Lloss = (kc+ke)*(1./(4*f))*d;\n",
"Lpipe = 137.;\n",
"L = Lpipe+Lfittings+Lloss;\n",
"deltap = deltapbyL*L;\n",
"patm = 14.696; \t\t\t #[psi] - atmospheric pressure\n",
"p1 = patm+deltap;\n",
"print \" a)The inlet pressure is p1 = %.1f psi\"%(p1);\n",
"\n",
"# (b) loss coefficient method\n",
"# using the equation deltap/p = -(Fpipe+Ffittings+Floss)\n",
"L = 137.;\n",
"kfittings = 52.39;\n",
"sigmaF = ((4.*f*(L/d))+kc+ke+kfittings)*((U**2)/(2*gc));\n",
"deltap = (p*sigmaF)/(144.);\n",
"p1 = patm+deltap;\n",
"\n",
"# Results\n",
"print \" b)The inlet pressure is p1 = %.1f psi\"%(p1);\n",
"print \" Computation of the pressure drop by the loss coefficient method differs from the equivalent length \\\n",
" \\nmethod by less than 1 psi\";\n"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
" a)The inlet pressure is p1 = 26.7 psi\n",
" b)The inlet pressure is p1 = 27.2 psi\n",
" Computation of the pressure drop by the loss coefficient method differs from the equivalent length \n",
"method by less than 1 psi\n"
]
}
],
"prompt_number": 34
},
{
"cell_type": "heading",
"level": 3,
"metadata": {},
"source": [
"Example 10.9 - Page No :443\n"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"# Determine the total flow rate of water through the pipe system.\n",
"\n",
"# Variables\n",
"L1 = 50.; \t\t\t #[m] - length of first pipe\n",
"L2 = 150.; \t\t\t #[m] - length of second pipe\n",
"L3 = 100.; \t\t\t #[m] - length of third pipe\n",
"d1 = 0.04; \t\t\t #[m] - diameter of first pipe\n",
"d2 = 0.06; \t\t\t #[m] - diameter of second pipe\n",
"d3 = 0.08; \t\t\t #[m] - diameter of third pipe\n",
"deltap = -1.47*10**5; \t\t\t #[kg/m*sec] - pressure drop\n",
"mu = 1*10.**-3; \t\t\t #[kg/m*sec] - vismath.cosity\n",
"p = 1000.; \t\t\t #[kg/m**3] - density\n",
"\n",
"# Calculation and Results\n",
"# for branch 1\n",
"S = (math.pi*(d1**2))/4;\n",
"Nvk = ((d1*p)/mu)*(-(d1*deltap)/(2*L1*p))**(1./2);\n",
"f = (1./(4*math.log10(Nvk)-0.4))**2;\n",
"U = (((-deltap)/p)*(d1/L1)*(2./4)*(1./f))**(1./2);\n",
"w1 = p*U*S;\n",
"print \" For first branch w1 = %.2f kg/sec\"%(w1);\n",
"\t\t\t # for branch 2\n",
"S = (math.pi*(d2**2))/4;\n",
"Nvk = ((d2*p)/mu)*(-(d2*deltap)/(2*L2*p))**(1./2);\n",
"f = (1./(4*math.log10(Nvk)-0.4))**2;\n",
"U = (((-deltap)/p)*(d2/L2)*(2./4)*(1./f))**(1./2);\n",
"w2 = p*U*S;\n",
"print \" For second branch w2 = %.2f kg/sec\"%(w2);\n",
"\t\t\t # for branch 3\n",
"S = (math.pi*(d3**2))/4;\n",
"Nvk = ((d3*p)/mu)*(-(d3*deltap)/(2*L3*p))**(1./2);\n",
"f = (1./(4*math.log10(Nvk)-0.4))**2;\n",
"U = (((-deltap)/p)*(d3/L3)*(2./4)*(1./f))**(1./2);\n",
"w3 = p*U*S;\n",
"print \" For third branch w3 = %.2f kg/sec\"%(w3);\n",
"\n",
"# total flow rate w = w1+w2+w3\n",
"w = w1+w2+w3;\n",
"print \" total flow rate is w = %.1f kg/sec\"%(w);\n"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
" For first branch w1 = 4.74 kg/sec\n",
" For second branch w2 = 7.59 kg/sec\n",
" For third branch w3 = 20.42 kg/sec\n",
" total flow rate is w = 32.7 kg/sec\n"
]
}
],
"prompt_number": 36
},
{
"cell_type": "heading",
"level": 3,
"metadata": {},
"source": [
"Example 10.10 Page no : 445"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"# find flow rate\n",
"\n",
"import math\n",
"\n",
"# Note : all variables values are taken from 10.9\n",
"# variables \n",
"w1 = 4.74 #kg/sec\n",
"w2 = 7.59 #kg/sec\n",
"w3 = 20.42 #kg/sec\n",
"w = 32.7 #kg/sec\n",
"d = .04\n",
"\n",
"S1 = math.pi*d**2/4\n",
"S2 = .002827\n",
"S3 = .005027\n",
"deltaP = 1.47 * 10**5 #kpa\n",
"deltaP1 = 1.583* 10**6 #f1w**2\n",
"deltaP2 = 6.254* 10**5 #f1w**2\n",
"deltaP3 = 9.895* 10**4 #f1w**2\n",
"Nre1 = 3.183 * 10**4 #w\n",
"Nre2 = 2.122 * 10**4 #w\n",
"Nre3 = 1.592 * 10**4 #w\n",
"\n",
"\n",
"### age plz tu kar dena muje kuchh samaj nahi aa raha he...\n",
"### Thanks in advance..... nahi to ye delete kar dena... mere se nahi hota. plz.\n",
"print S1\n"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"0.00125663706144\n"
]
}
],
"prompt_number": 1
},
{
"cell_type": "heading",
"level": 3,
"metadata": {},
"source": [
"Example 10.11 - Page No : 447\n"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"'''\n",
"Determine the pump size necessary to maintain a spray\n",
"velocity of 15 ft s-\u2019 and a flow rate of 400 gpm if the pump is 60 percent efficient.\n",
"'''\n",
"\n",
"# Variables\n",
"sp = 1.1;\n",
"p = sp*62.4; \t\t\t #[lb/ft**3] - density\n",
"mu = 2*6.72*10**-4; \t #[lb/ft*sec] - viscosity\n",
"Q = 400.; \t\t\t #[gpm] - volumetric flow rate\n",
"e = 1.5*10**4; \t\t #roughness of steel pipe\n",
"gc = 32.174;\n",
"kexit = 1.;\n",
"kentrance = 0.5;\n",
"\n",
"# Calculations\n",
"# 4 in schedule pipe\n",
"d = 4.026/12; \t\t\t #[ft]\n",
"U4 = Q/39.6; \t\t\t #[ft/sec]\n",
"Lgv = 13.08;\n",
"Lglv = 114.1;\n",
"Le = 40.26;\n",
"Lpipe_4 = 22.;\n",
"Lfittings_4 = Lgv+Lglv+Le;\n",
"Lloss = 0;\n",
"L_4 = Lpipe_4+Lfittings_4+Lloss;\n",
"Nre_4 = (d*U4*p)/mu;\n",
"f = 0.00475;\n",
"Fpipe_4 = ((4*f*L_4)/d)*(U4**2)*(1/(2*gc));\n",
"Floss_4 = ((kentrance+0)*(U4**2))/(2*gc);\n",
"\n",
"# 5 in schedule pipe\n",
"d = 5.047/12;\n",
"U5 = Q/62.3;\n",
"Lgv = 10.94;\n",
"Le = 75.71;\n",
"Lpipe_5 = 100.;\n",
"Lfittings_5 = Lgv+Le;\n",
"Lloss = 0.;\n",
"L_5 = Lpipe_5+Lfittings_5+Lloss;\n",
"Nre = (d*U5*p)/mu;\n",
"f = 0.00470;\n",
"Fpipe_5 = ((4*f*L_5)/d)*(U5**2)*(1./(2*gc));\n",
"Floss_5 = ((kexit+0)*(U5**2))/(2*gc);\n",
"\n",
"# 6 in schedule pipe\n",
"d = 6.065/12;\n",
"U6 = Q/90.;\n",
"Lgv = 6.570;\n",
"Le = 30.36;\n",
"Lpipe_6 = 4.;\n",
"Lfittings_6 = Lgv+Le;\n",
"Lloss = 0.;\n",
"L_6 = Lpipe_6+Lfittings_6+Lloss;\n",
"Nre = (d*U6*p)/mu;\n",
"f = 0.00487;\n",
"Fpipe_6 = ((4*f*L_6)/d)*(U6**2)*(1./(2*gc));\n",
"kc = 0.50;\n",
"Floss_6 = kc*((U6**2)/(2*gc));\n",
"Ffittings = 0.;\n",
"deltap_6 = p*(Fpipe_6+Ffittings+Floss_6);\n",
"\n",
"# 3/4 in 18 gauge tube\n",
"d = 0.652112/12;\n",
"L_3by4 = 15.;\n",
"U_3by4 = (Q*0.962)/100.;\n",
"Floss_3by4 = 100.*(kexit+kentrance)*((U_3by4**2.)/2.);\n",
"Nre = d*U_3by4*p*(1./mu);\n",
"f = 0.08*((Nre)**(-1./4))+0.012*((d)**(1./2));\n",
"deltap_3by4 = ((4*f*p*L_3by4)/d)*((U_3by4**2)/(2*gc));\n",
"Fpipe_3by4 = 100.*((4.*f*L_3by4)/d)*((U_3by4**2.)/(2.*gc));\n",
"deltap_spraysystem = 25.; \t\t\t #[psi]\n",
"Fspraysystem = (deltap_spraysystem/p)*(144.);\n",
"delta_p = (p*(kexit+kentrance))*((U_3by4**2.)/(2.*gc))\n",
"Fpipe = Fpipe_4+Fpipe_5+Fpipe_6;\n",
"Floss = Floss_4+Floss_5+Floss_6+Floss_3by4;\n",
"ws = 0. + (((15.**2)-0)/(2*gc))+38.9+382.5;\n",
"w = (Q*p)/(7.48);\n",
"Ws = (ws*w)/(33000.);\n",
"efficiency = 0.6;\n",
"Ws_actual = Ws/efficiency\n",
"\n",
"# Results\n",
"print \" The power supplied to the pump is %.1f hp\"%(Ws_actual);\n"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
" The power supplied to the pump is 78.8 hp\n"
]
}
],
"prompt_number": 7
},
{
"cell_type": "heading",
"level": 3,
"metadata": {},
"source": [
"Example 10.12 - Page No :454\n"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"# Estimate the power required in the previous problem by using the velocity head approximation\n",
"\n",
"# Variables\n",
"kexit = 1.;\n",
"kentrance = 0.5;\n",
"Q = 400.; \t\t\t #[gpm] - volumetric flow rate\n",
"gc = 32.174;\n",
"\n",
"# for 4 inch pipe\n",
"d = 4.026; \t\t #[inch]\n",
"L = 22.; \t\t\t #[ft]\n",
"Lbyd = (L*12)/(d);\n",
"\n",
"# Calculation and Results\n",
"# adding the contributions due to fittings \n",
"Lbyd = Lbyd+3*13+340+4*30;\n",
"N = Lbyd/45.;\n",
"N = N+kentrance+0;\n",
"U4 = Q/39.6; \t\t\t #[ft/sec]\n",
"Fpipe_4 = (N*(U4**2))/(2*gc);\n",
"print \" F4 in.pipes = %.2f ft*lbf/lbm\"%(Fpipe_4);\n",
"\n",
"# for 5 inch pipe\n",
"L = 100.; \t\t\t #[ft]\n",
"d = 5.047; \t\t\t #[inch]\n",
"Lbyd = (L*12.)/(d);\n",
"\n",
"# valves contributes 26 diameters and six elbows contribute 30 diameters ecah;therefore\n",
"Lbyd = Lbyd+26+6*30;\n",
"N = Lbyd/45.; \t\t\t # no. of velocity heads\n",
"N = N+kexit+kentrance;\n",
"U5 = Q/62.3;\n",
"Fpipe_5 = (N*(U5**2))/(2*gc);\n",
"print \" F5 in.pipes = %.2f ft*lbf/lbm\"%(Fpipe_5);\n",
"\n",
"# for 6 inch pipe\n",
"d = 6.065; \t\t #[inch]\n",
"L = 5.; \t\t\t #[ft]\n",
"Lbyd = (L*12.)/(d);\n",
"\n",
"# adding the contributions due to fittings \n",
"Lbyd = Lbyd+1*13+2*30;\n",
"N = Lbyd/45;\n",
"N = N+0+kentrance;\n",
"U6 = Q/90.;\n",
"Fpipe_6 = (N*(U6**2))/(2*gc);\n",
"print \" F6 in.pipes = %.3f ft*lbf/lbm\"%(Fpipe_6);\n",
"F_largepipes = Fpipe_4+Fpipe_5+Fpipe_6;\n",
"print \" Flarge pipes = %.2f ft*lbf/lbm\"%(F_largepipes);\n"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
" F4 in.pipes = 20.69 ft*lbf/lbm\n",
" F5 in.pipes = 7.28 ft*lbf/lbm\n",
" F6 in.pipes = 0.719 ft*lbf/lbm\n",
" Flarge pipes = 28.68 ft*lbf/lbm\n"
]
}
],
"prompt_number": 39
},
{
"cell_type": "heading",
"level": 3,
"metadata": {},
"source": [
"Example 10.14 - Page No :459\n"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"# Determine the pressure drop over a length of 300 m if the flow velocity is 1.667 m\n",
"\n",
"\n",
"# Variables\n",
"l = 0.09238;\n",
"rh = 0.1624*l;\n",
"L = 300.;\n",
"de = 4.*rh;\n",
"p = 1000.; \t\t\t #[kg/m**3]\n",
"mu = 10.**-3; \t\t\t #[kg/m*sec]\n",
"Uavg = 1.667;\n",
"\n",
"# Calculations\n",
"Nre = (de*Uavg*p)/mu;\n",
"f = 0.0053;\n",
"deltap = ((4.*f*L)/de)*(p*(Uavg**2)*(1./2));\n",
"\n",
"# Results\n",
"print \" Pressure drop -deltap = %.3e kg/m*s = %.3e N/m**2 = %.1f kPa\"%(deltap,deltap,deltap*10**-3);\n"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
" Pressure drop -deltap = 1.473e+05 kg/m*s = 1.473e+05 N/m**2 = 147.3 kPa\n"
]
}
],
"prompt_number": 8
},
{
"cell_type": "heading",
"level": 3,
"metadata": {},
"source": [
"Example 10.15 - Page No :466\n"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"'''\n",
"Size a sharp-edged, corner-tap orifice meter for the 4-in. leg in\n",
"Fig. 10.17 if the flow rate and fluid are unchanged from Example 10.11.\n",
"'''\n",
"\n",
"# Variables\n",
"Q = 400.; \t\t\t #[gpm]\n",
"p = 1.1*62.4; \t \t\t #[lbm/ft**3]\n",
"mu = 2.*(6.72*10**-4); \t #[lb/ft*sec]\n",
"e = 1.5*10**4;\n",
"\n",
"# Calculations\n",
"# 4 inch schedule pipe\n",
"d = 0.3355;\n",
"S = (math.pi*(d**2))/4;\n",
"U4 = Q/39.6;\n",
"ebyd = e/d;\n",
"w = 3671./60;\n",
"pm = 13.45*62.4;\n",
"g = 32.1;\n",
"gc = 32.174;\n",
"deltaz = 2.5;\n",
"deltap = (g/gc)*(pm-p)*(deltaz);\n",
"betaa = ((1.)/(1.+((2*p*gc)*(deltap))*(((0.61*S)/w)**2)))**(1./4);\n",
"d2 = betaa*d;\n",
"Nre2 = (4*w)/(math.pi*d2*mu);\n",
"a = (1./30)*4.026;\n",
"b = (1./4)*(2.013-1.21);\n",
"c = (1./8)*(2.42);\n",
"if a<b :\n",
" if a<c :\n",
" opt = a;\n",
" else:\n",
" opt = c;\n",
"else:\n",
" if b<c:\n",
" opt = b;\n",
" else:\n",
" opt = c;\n",
"\n",
"# Results\n",
"print \" The pertinent orifice details are orifice diameter = %.3f in corner taps, \\\n",
" \\n square edge orifice plate not over %.3f in thick\"%(d2*12,opt);"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
" The pertinent orifice details are orifice diameter = 2.425 in corner taps, \n",
" square edge orifice plate not over 0.134 in thick\n"
]
}
],
"prompt_number": 42
},
{
"cell_type": "heading",
"level": 3,
"metadata": {},
"source": [
"Example 10.16 - Page No :470\n"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"# Size a venturi meter for the application cited in Example 10.15\n",
"\n",
"# Variables\n",
"Q = 400.; \t \t\t #[gpm]\n",
"p = 1.1*62.4; \t\t\t #[lbm/ft**3]\n",
"mu = 2*(6.72*10**-4); \t\t\t #[lb/ft*sec]\n",
"e = 1.5*10**4;\n",
"\n",
"# Calculations\n",
"# 4 inch schedule pipe\n",
"d = 0.3355;\n",
"S = (math.pi*(d**2))/4;\n",
"U4 = Q/39.6;\n",
"ebyd = e/d;\n",
"w = 3671./60;\n",
"pm = 13.45*62.4;\n",
"g = 32.1;\n",
"gc = 32.174;\n",
"Nre = (d*U4*p)/mu;\n",
"if Nre>10**4:\n",
" c = 0.98;\n",
"\n",
"deltaz = 2.5;\n",
"deltap = (g/gc)*(pm-p)*(deltaz);\n",
"betaa = ((1.)/(1+((2*p*gc)*(deltap))*(((c*S)/w)**2)))**(1./4);\n",
"d2 = betaa*d;\n",
"\n",
"# Results\n",
"print \" The pertinentr details of the venturi design are Throat diameter = %.2f inch \\\n",
"\\n Approach angle = 25 Divergence angle = 7\"%(d2*12);\n",
"\n"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
" The pertinentr details of the venturi design are Throat diameter = 1.95 inch \n",
" Approach angle = 25 Divergence angle = 7\n"
]
}
],
"prompt_number": 44
},
{
"cell_type": "heading",
"level": 3,
"metadata": {},
"source": [
"Example 10.17 - Page No :477\n"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"# Then compute the average velocity by Eq. (10.88) and compare with the 2.778 ft s-l as given.\n",
"\n",
"# Variables\n",
"Uzmax = 3.455; \t\t\t #[ft/sec]\n",
"m = 32;\n",
"a1 = -0.3527;\n",
"a2 = -0.6473;\n",
"rbyro = 0.880;\n",
"\n",
"# Calculations\n",
"UzbyUzmax = 1+a1*(rbyro**2)+a2*(rbyro**(2*m));\n",
"Uz = Uzmax*(UzbyUzmax);\n",
"Uzavg = (4./9)*Uzmax+(5./18)*(Uz+Uz);\n",
"\n",
"# Results\n",
"print \" the average velocity is Uzavg = %.2f ft/sec \\\n",
"\\n Thus, in this Example there is an inherent error of 5.5 percent, even before any experimental errors are introduced\"%(Uzavg);\n"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
" the average velocity is Uzavg = 2.93 ft/sec \n",
" Thus, in this Example there is an inherent error of 5.5 percent, even before any experimental errors are introduced\n"
]
}
],
"prompt_number": 10
}
],
"metadata": {}
}
]
}
|