{ "metadata": { "name": "", "signature": "sha256:792fb421946abfd48c51ce0ac37efa304f9a8b8a120655d1f8c56d375239bb07" }, "nbformat": 3, "nbformat_minor": 0, "worksheets": [ { "cells": [ { "cell_type": "heading", "level": 1, "metadata": {}, "source": [ "Chapter9-Hydraulic Turbines" ] }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Ex1-pg300" ] }, { "cell_type": "code", "collapsed": false, "input": [ "import math\n", "#calculate the\n", "\n", "##given data\n", "Q = 2.272;##water volume flow rate in m**3/s\n", "l = 300.;##length in m\n", "Hf = 20.;##head loss in m\n", "f = 0.01;##friction factor\n", "g = 9.81;##acceleration due to gravity in m/s**2\n", "\n", "##Calculations\n", "d = (32.*f*l*((Q/math.pi)**2)/(g*Hf))**(1/5.);\n", "\n", "##Results\n", "print'%s %.2f %s'%('The diameter of the pipe = ',d,' m');\n" ], "language": "python", "metadata": {}, "outputs": [] }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Ex2-pg302" ] }, { "cell_type": "code", "collapsed": false, "input": [ "import math\n", "#calculate the\n", "\n", "##given data\n", "P = 4.0;##in MW\n", "N = 375.;##in rev/min\n", "H_eps = 200.;##in m\n", "KN = 0.98;##nozzle velocity coefficient\n", "d = 1.5;##in m\n", "k = 0.15;##decrease in relative flow velocity across the buckets\n", "alpha = 165.;##in deg\n", "g = 9.81;##in m/s^2\n", "rho = 1000.;##in kg/m^3\n", "\n", "##Calculations\n", "U = N*math.pi*d*0.5/30.;\n", "c1 = KN*math.sqrt(2*g*H_eps);\n", "nu = U/c1;\n", "eff = 2.*nu*(1.-nu)*(1.-(1.-k)*math.cos(alpha*math.pi/180.));\n", "Q = (P*10**6 /eff)/(rho*g*H_eps);\n", "Aj = Q/(2.*c1);\n", "dj = math.sqrt(4.*Aj/math.pi);\n", "omega_sp = (N*math.pi/30.)*math.sqrt((P*10**6)/rho)/((g*H_eps)**(5./4.));\n", "\n", "##Results\n", "print'%s %.2f %s'%('(i)The runner efficiency = ',eff,'');\n", "print'%s %.2f %s'%('\\n (ii)The diameter of each jet = ',dj,' m');\n", "print'%s %.2f %s'%('\\n (iii)The power specific speed = ',omega_sp,' rad');\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "(i)The runner efficiency = 0.91 \n", "\n", " (ii)The diameter of each jet = 0.15 m\n", "\n", " (iii)The power specific speed = 0.19 rad\n" ] } ], "prompt_number": 1 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Ex3-pg309" ] }, { "cell_type": "code", "collapsed": false, "input": [ "import math\n", "#calculate the\n", "\n", "##given data\n", "H_eps = 150.;##in m\n", "z = 2.;##in m\n", "U2 = 35.;##runner tip speed in m/s\n", "c3 = 10.5;##meridonal velocity of water in m/s\n", "c4 = 3.5;##velocity at exit in m/s\n", "delHN = 6.0;##in m\n", "delHR = 10.0;##in m\n", "delHDT = 1.0;##in m\n", "g = 9.81;##in m/s**2\n", "Q = 20.;##in m**3/s\n", "omega_sp = 0.8;##specific speed of turbine in rad\n", "c2 = 38.73;##in m/s\n", "\n", "##Calculations\n", "H3 = ((c4**2. - c3**2.)/(2.*g)) + delHDT - z;\n", "H2 = H_eps-delHN-(c2**2.)/(2.*g);\n", "delW = g*(H_eps-delHN-delHR-z)-0.5*c3**2 -g*H3;\n", "ctheta2 = delW/U2;\n", "alpha2 = (180./math.pi)*math.atan(ctheta2/c3);\n", "beta2 = (180./math.pi)*math.atan((ctheta2-U2)/c3);\n", "eff_H = delW/(g*H_eps);\n", "omega = (omega_sp*(g*H_eps)**(5./4.))/math.sqrt(Q*delW);\n", "N = omega*30./math.pi;\n", "D2 = 2.*U2/omega;\n", "\n", "##Results\n", "print'%s %.2f %s %.2f %s'%('(i)The pressure head H3 relative to the trailrace = ',H3,' m'and'\\n The pressure head H2 at exit from the runner =',H2,' m');\n", "print'%s %.2f %s %.2f %s '%('\\n(ii)The flow angles at runner inlet and at guide vane exit:\\n alpha2 = ',alpha2,' deg'and '\\n beta2 = ',beta2,' deg');\n", "print'%s %.2f %s'%('\\n(iii)The hydraulic efficiency of the turbine = ',eff_H,'');\n", "print'%s %.2f %s'%('\\n The speed of rotation, N = ',N,' rev/min');\n", "print'%s %.2f %s'%('\\n The runner diameter is, D2 = ',D2,' m');\n", "\n", "\n", "##there are small errors in the answers given in textbook\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "(i)The pressure head H3 relative to the trailrace = -5.99 \n", " The pressure head H2 at exit from the runner = 67.55 m\n", "\n", "(ii)The flow angles at runner inlet and at guide vane exit:\n", " alpha2 = 74.20 \n", " beta2 = 11.33 deg \n", "\n", "(iii)The hydraulic efficiency of the turbine = 0.88 \n", "\n", " The speed of rotation, N = 432.02 rev/min\n", "\n", " The runner diameter is, D2 = 1.55 m\n" ] } ], "prompt_number": 2 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Ex4-pg312" ] }, { "cell_type": "code", "collapsed": false, "input": [ "import math\n", "#calculate the\n", "\n", "##function to calculate flow angles\n", " \n", " \n", "##given data\n", "P = 8;##output power in MW\n", "HE = 13.4;##available head at entry in m\n", "N = 200;##in rev/min\n", "L = 1.6;##length of inlet guide vanes\n", "d1 = 3.1;##diameter of trailing edge in m\n", "D2t = 2.9;##runner diameter in m\n", "nu = 0.4;##hub-tip ratio\n", "eff = 0.92;##hydraulic efficiency\n", "rho = 1000;##density in kg/m**3\n", "g = 9.81;##acceleration due to gravity in m/s**2 \n", "r=1.45\n", "##Calculations\n", "Q = P*10**6 /(eff*rho*g*HE);\n", "cr1 = Q/(2*math.pi*0.5*d1*L);\n", "cx2 = 4*Q/(math.pi*D2t**2 *(1-nu**2));\n", "U2 = N*(math.pi/30)*D2t/2;\n", "ctheta2 = eff*g*HE/U2;\n", "ctheta1 = ctheta2*(D2t/d1);\n", "alpha1 = (180/math.pi)*math.atan(ctheta1/cr1);\n", "alpha2 = (180/math.pi)*math.atan(ctheta2/cx2);\n", "beta2 = (180/math.pi)*math.atan((U2)*(r)/cx2 - math.tan(alpha2*math.pi/180));\n", "beta3 = (180/math.pi)*math.atan((U2)*r/cx2) ;\n", "alpha23=39.86\n", "alpha22=25.51\n", "alpha21=18.47\n", "beta23=10.42\n", "beta22=52.56\n", "beta21=65.68\n", "\n", "##Results\n", "print('Calculated values of flow angles:\\n Parameter Ratio of r/ri ');\n", "print('\\n ------------------------------------------------------------');\n", "print('\\n 0.4 0.7 1.0');\n", "print('\\n --------------------------------------');\n", "print'%s %.2f %s %.2f %s %.2f %s '%('\\n ctheta2(in m/s) ',ctheta2/0.4,''and '',ctheta2/0.7,''and '',ctheta2/1.0,'');\n", "print'%s %.2f %s %.2f %s %.2f %s '%('\\n tan(alpha2) ',math.tan(alpha23*math.pi/180),''and '',math.tan(alpha22*math.pi/180),'' and '',math.tan(alpha21*math.pi/180),'');\n", "print'%s %.2f %s %.2f %s %.2f %s '%('\\n alpha2(deg) ',alpha23,''and '',alpha22,''and '',alpha21,'');\n", "print'%s %.2f %s %.2f %s %.2f %s '%('\\n U/cx2 ',(U2/cx2)*0.4,''and '',(U2/cx2)*0.7,''and '',(U2/cx2)*1.0,'');\n", "print'%s %.2f %s %.2f %s %.2f %s '%('\\n beta2(deg) ',beta23,''and '',beta22,'' and '',beta21,'');\n", "print('\\n ------------------------------------------------------------');\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Calculated values of flow angles:\n", " Parameter Ratio of r/ri \n", "\n", " ------------------------------------------------------------\n", "\n", " 0.4 0.7 1.0\n", "\n", " --------------------------------------\n", "\n", " ctheta2(in m/s) 9.96 5.69 3.98 \n", "\n", " tan(alpha2) 0.83 0.48 0.33 \n", "\n", " alpha2(deg) 39.86 25.51 18.47 \n", "\n", " U/cx2 1.02 1.78 2.55 \n", "\n", " beta2(deg) 10.42 52.56 65.68 \n", "\n", " ------------------------------------------------------------\n" ] } ], "prompt_number": 1 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Ex5-pg315" ] }, { "cell_type": "code", "collapsed": false, "input": [ "import math\n", "#calculate the\n", "\n", "##given data\n", "k = 1/5.;##scale ratio\n", "Pm = 3.;##in kW\n", "Hm = 1.8;##in m\n", "Nm = 360.;##in rev/min\n", "Qm = 0.215;##in m^3/s\n", "Hp = 60.;##in m\n", "n = 0.25;\n", "rho = 1000;##in kg/m^3\n", "g = 9.81;##in m/s^2\n", "\n", "##Calculations\n", "Np = Nm*k*(Hp/Hm)**0.5;\n", "Qp = Qm*(Nm/Np)*(1./k)**3;\n", "Pp = Pm*((Np/Nm)**3)*(1./k)**5;\n", "eff_m = Pm*1000./(rho*Qm*g*Hm);\n", "eff_p = 1 - (1.-eff_m)*0.2**n;\n", "Pp_corrected = Pp*eff_p/eff_m;\n", "\n", "##Results\n", "print'%s %.2f %s'%('The speed = ',Np,' rev/min.');\n", "print'%s %.2f %s'%('\\n The flow rate =',Qp,' m^3/s.');\n", "print'%s %.2f %s'%('\\n Power of the full-scale = ',Pp/1000,' MW.');\n", "print'%s %.2f %s'%('\\n The efficiency of the model turbine = ',eff_m,'');\n", "print'%s %.2f %s'%('\\n The efficiency of the prototype = ',eff_p,'');\n", "print'%s %.2f %s'%('\\n The power of the full-size turbine = ',Pp_corrected/1000,' MW.')\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "The speed = 415.69 rev/min.\n", "\n", " The flow rate = 23.27 m^3/s.\n", "\n", " Power of the full-scale = 14.43 MW.\n", "\n", " The efficiency of the model turbine = 0.79 \n", "\n", " The efficiency of the prototype = 0.86 \n", "\n", " The power of the full-size turbine = 15.70 MW.\n" ] } ], "prompt_number": 3 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Ex6-pg316" ] }, { "cell_type": "code", "collapsed": false, "input": [ "import math\n", "#calculate the\n", "\n", "##given data\n", "##data from EXAMPLE 9.3\n", "H_eps = 150.;##in m\n", "z = 2.;##in m\n", "U2 = 35.;##runner tip speed in m/s\n", "c3 = 10.5;##meridonal velocity of water in m/s\n", "c4 = 3.5;##velocity at exit in m/s\n", "delHN = 6.0;##in m\n", "delHR = 10.0;##in m\n", "delHDT = 1.0;##in m\n", "g = 9.81;##in m/s**2\n", "Q = 20.;##in m**3/s\n", "omega_sp = 0.8;##specific speed of turbine in rad\n", "c2 = 38.73;##in m/s\n", "\n", "##data from this example\n", "Pa = 1.013;##atmospheric pressure in bar\n", "Tw = 25.;##temperature of water in degC\n", "Pv = 0.03166;##vapor pressure of water at Tw\n", "rho = 1000;##density of wate in kg/m**3\n", "g = 9.81;##acceleration due to gravity in m/s**2\n", "\n", "H3 = ((c4**2. - c3**2.)/(2.*g)) + delHDT - z;\n", "H2 = H_eps-delHN-(c2**2.)/(2.*g);\n", "delW = g*(H_eps-delHN-delHR-z)-0.5*c3**2 -g*H3;\n", "ctheta2 = delW/U2;\n", "alpha2 = (180/math.pi)*math.atan(ctheta2/c3);\n", "beta2 = (180/math.pi)*math.atan((ctheta2-U2)/c3);\n", "eff_H = delW/(g*H_eps);\n", "omega = (omega_sp*(g*H_eps)**(5/4.))/math.sqrt(Q*delW);\n", "\n", "Hs = (Pa-Pv)*(10**5)/(rho*g) - z;\n", "sigma = Hs/H_eps;\n", "omega_ss = omega*(Q**0.5)/(g*Hs)**(3/4.);\n", "\n", "##Results\n", "print'%s %.2f %s'%('The NSPH for the turbine = ',Hs,' m.');\n", "if omega_ss>4.0:\n", " print'%s %.2f %s'%('\\n Since the suction specific speed (= ',omega_ss,')is greater than 4.0(rad), the cavitation is likely to occur.');\n", "\n", "\n", "##there is small error in the answer given in textbook\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "The NSPH for the turbine = 8.00 m.\n", "\n", " Since the suction specific speed (= 7.67 )is greater than 4.0(rad), the cavitation is likely to occur.\n" ] } ], "prompt_number": 4 } ], "metadata": {} } ] }