{ "metadata": { "name": "", "signature": "sha256:af2e84ceb74c3bc3148f31759e2a692dba979671e7232787c666481af8571437" }, "nbformat": 3, "nbformat_minor": 0, "worksheets": [ { "cells": [ { "cell_type": "heading", "level": 1, "metadata": {}, "source": [ "Chapter 11 : SPILLWAYS" ] }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 11.1 pg : 538" ] }, { "cell_type": "code", "collapsed": false, "input": [ "import math \n", "\n", "#Given\n", "h = 1.2; \t\t\t\t#head of water\n", "Cd = 2.2; \t\t\t\t#coefficient of discharge\n", "rho = 1; \t\t\t\t#density of water\n", "gamma_w = 9.81; \t\t\t\t#unit weigth of water\n", "\n", "q = Cd*h**1.5;\n", "\n", "#applying bernaulli's equation at u/s water surface at section A and B\n", "#solving it by error and trial method we get\n", "v1 = 13.7;v2 = 14.7;\n", "d1 = 0.212;d2 = 0.197;\n", "\n", "F1 = gamma_w*d1**2*math.cos(math.radians(60))/2;\n", "F2 = gamma_w*d2**2/2;\n", "W = gamma_w*60*2*math.pi*3*((d1+d2)/2)/360;\n", "Fx = rho*q*(v2-v1*math.cos(math.radians(60)))-F1/2+F2;\n", "Fy = rho*q*(v1*math.sin(math.radians(60)))+F1*math.sin(math.radians(60))+W;\n", "F = (Fx**2+Fy**2)**0.5;\n", "F = round(F*100)/100;\n", "\n", "# Results\n", "print \"Resultant force = %.2f kN/m.\"%(F);\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Resultant force = 46.68 kN/m.\n" ] } ], "prompt_number": 1 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 11.2 pg : 539" ] }, { "cell_type": "code", "collapsed": false, "input": [ "import math \n", "\t\t\t\t\n", "#Given\n", "C = 2.4; \t\t\t\t#coefficient of discharge\n", "H = 2; \t\t\t\t#head\n", "L = 100; \t\t\t\t#length of spillway\n", "wc = 8; \t\t\t\t#heigth of weir crest above bottom\n", "g = 9.81; \t\t\t\t#acceleration due to gravity\n", "\n", "# Calculations\n", "h = H+wc;\n", "Q1 = C*L*H**(1.5); \t\t\t\t#neglecting approach velocity and end contractions\n", "va = Q1/(h*L);\n", "ha = va**2/(2*g);\n", "Ha = ha+H;\n", "Q = C*L*Ha**1.5;\n", "Q = round(Q*10)/10;\n", "\n", "# Results\n", "print \"discharge over oggy weir = %.2f cumecs.\"%(Q);\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "discharge over oggy weir = 690.80 cumecs.\n" ] } ], "prompt_number": 2 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 11.3 pg : 540" ] }, { "cell_type": "code", "collapsed": false, "input": [ "import math \n", "\n", "#capacity of siphon\n", "#head required in oggy spillway\n", "#length of oggy weir required\n", "\n", "#Given\n", "t = 6; \t\t\t\t#tail water elevation\n", "h = 1; \t\t\t\t#heigth of siphon spillway\n", "w = 4; \t\t\t\t#width of siphon spillway\n", "hw = 1.5; \t\t\t\t#head water elevation\n", "C = 0.6; \t\t\t\t#coefficient of discharge\n", "Co = 2.25; \t\t\t\t#coefficient of discharge of oggy spillway\n", "lo = 4; \t\t\t\t#length of oggy spillway\n", "hc = 1.5; \t\t\t\t#head on weir crest\n", "g = 9.81; \t\t\t\t#acceleration due to gravity\n", "\n", "# Calculations and Results\n", "#part (a)\n", "Q = C*h*w*(2*g*(t+hw))**0.5;\n", "Q = round(Q*10)/10;\n", "print \"capacity of siphon = %.2f cumecs.\"%(Q);\n", "\n", "#part (b)\n", "h1 = (Q/(Co*lo))**(2./3);\n", "h1 = round(h1*100)/100;\n", "print \"head required in oggy spillway = %.2f m\"%(h1);\n", "\n", "#part (c)\n", "L = Q/(Co*(hc)**1.5);\n", "L = round(L*100)/100;\n", "print \"length of oggy weir required = %.2f m.\"%(L);\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "capacity of siphon = 29.10 cumecs.\n", "head required in oggy spillway = 2.19 m\n", "length of oggy weir required = 7.04 m.\n" ] } ], "prompt_number": 3 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 11.4 pg : 540" ] }, { "cell_type": "code", "collapsed": false, "input": [ "import math \n", "\n", "\n", "\t\t\t\t\n", "#Given\n", "rl = 435; \t\t\t\t#full reservior level\n", "cl = 429.6; \t\t\t\t#level of centre of siphon\n", "hfl = 435.85; \t\t\t\t#high flood level\n", "hfd = 600; \t\t\t\t#high flood discharge\n", "w = 4; \t\t\t\t#width of throat\n", "h = 2; \t\t\t\t#heigth of throat\n", "C = 0.65; \t\t\t\t#coefficient of discharge\n", "g = 9.81; \t\t\t\t#acceleration due to gravity\n", "\n", "# Calculations\n", "H = hfl-cl;\n", "Q = C*w*h*(2*g*H)**0.5;\n", "n = hfd/Q;\n", "n = round(n*100)/100;\n", "\n", "# Results\n", "print \" number of siphons units required = %.2f.hence provide 11 siphons units.\"%(n);\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ " number of siphons units required = 10.42.hence provide 11 siphons units.\n" ] } ], "prompt_number": 4 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 11.5 pg : 541" ] }, { "cell_type": "code", "collapsed": false, "input": [ "import math \n", "from numpy import arange,zeros\n", "\n", "#design oggy spillway for concrete gravity dam\n", "\n", "#Given\n", "rbl = 250; \t\t\t\t#avarage river bed level\n", "rlc = 350; \t\t\t\t#R.L of spillway crest\n", "s = 0.75; \t\t\t\t#slope on downstream side\n", "Q = 6500; \t\t\t\t#discharge\n", "L = 5*9; \t\t\t\t#length of spillway\n", "Cd = 2.2; \t\t\t\t#coefficient of discharge\n", "t = 2; \t\t\t\t#thickness of each pier\n", "\n", "#step 1. computation of design head\n", "H = (Q/(Cd*L))**(2./3);\n", "P = rlc-rbl;\n", "\n", "#P/H = 6.15,which is<1.33;it is a high overflow spillway\n", "\n", "#H+P/H = 7.15>1.7; hence discharge coefficient is not affected by downstream apron interface\n", "\n", "Kp = 0.01;\n", "Ka = 0.1;\n", "N = 4;\n", "He = 17.5; \t\t\t\t#assumed\n", "Le = L-2*(N*Kp+Ka)*He;\n", "He1 = (Q/(Cd*Le))**(2./3);\n", "He1 = round(He1*100)/100;\n", "#He1 is almost equal to He\n", "print \"crest profile will be designed for Hd = %.2f m.\"%(He1);\n", "\n", "#step 2. determination of d/s profile\n", "\n", "#equating the slope of d/s side and derivative of profile equation suggested by WES\n", "x = 27.03;\n", "y = 0.04372*x**1.85;\n", "print \"downstream profile:\";\n", "x = arange(1,27)\n", "y = zeros(26)\n", "for i in range(26):\n", " y[i] = 0.04372*x[i]**1.85;\n", " y[i] = round(y[i]*1000)/1000;\n", "\n", "print \"x y\";\n", "for i in range(26):\n", " print \"%i %.2f\"%(x[i],y[i]);\n", "\n", "print \"27.03 19.48\";\n", "#step 3. determination of u/s profile\n", "# math.cosidering equation for vertical u/s face and Hd = 17.58\n", "\n", "print \"upstream profile:\";\n", "x = [-0.5, -0.1, -1.5, -2.0, -3.0, -4.0, -4.75];\n", "y = zeros(7)\n", "for i in range(7):\n", " if i==6:\n", " y[i] = 0.0633*(x[i]+4.75)**1.85+2.2151-1.2643*(x[i]+4.75)**0.625;\n", " y[i] = round(y[i]*1000)/1000;\n", " continue\n", " \n", " y[i] = 0.0633*(x[i]+4.7466)**1.85+2.2151-1.2643*(x[i]+4.7466)**0.625;\n", " y[i] = round(y[i]*1000)/1000;\n", "\n", "print \"x y\";\n", "for i in range(7):\n", " print \"%.2f %.2f\"%(x[i],y[i]);\n", "\n", "\n", "#step 4.design of d/s bucket\n", "\n", "R = P/4;\n", "print \"radius of bucket = %i m.\"%(R);\n", "print \"bucket will subtend angle of 60 degree at the centre.\";\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "crest profile will be designed for Hd = 17.58 m.\n", "downstream profile:\n", "x y\n", "1 0.04\n", "2 0.16\n", "3 0.33\n", "4 0.57\n", "5 0.86\n", "6 1.20\n", "7 1.60\n", "8 2.05\n", "9 2.55\n", "10 3.10\n", "11 3.69\n", "12 4.34\n", "13 5.03\n", "14 5.77\n", "15 6.55\n", "16 7.38\n", "17 8.26\n", "18 9.18\n", "19 10.15\n", "20 11.16\n", "21 12.21\n", "22 13.31\n", "23 14.45\n", "24 15.63\n", "25 16.86\n", "26 18.13\n", "27.03 19.48\n", "upstream profile:\n", "x y\n", "-0.50 0.01\n", "-0.10 -0.00\n", "-1.50 0.14\n", "-2.00 0.25\n", "-3.00 0.60\n", "-4.00 1.20\n", "-4.75 2.21\n", "radius of bucket = 25 m.\n", "bucket will subtend angle of 60 degree at the centre.\n" ] } ], "prompt_number": 6 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 11.6 pg : 562" ] }, { "cell_type": "code", "collapsed": false, "input": [ "import math \n", "\n", "\t\t\t\t#design length and depth of stilling bamath.sin\n", "\t\t\t\t\n", "#Given\n", "q = 1; \t\t\t\t#discharge of spillway\n", "Cd = 0.7; \t\t\t\t#coefficient of discharge\n", "h1 = 10; \t\t\t\t#heigth of crest above downstream silting bamath.sin\n", "g = 9.81; \t\t\t\t#acceleration due to gravity\n", "Cv = 0.9; \t\t\t\t#coefficient of velocity\n", "\n", "# Calculations\n", "h = (3*q/(2*Cd*(2*g)**0.5))**(2./3);\n", "H = h1+h/2;\n", "vt = (2*g*H)**0.5;\n", "v1 = Cv*vt;\n", "y1 = q/v1;\n", "F1 = v1/(g*y1)**0.5;\n", "\t\t\t\t#F>1, flow is super-critical\n", "y2 = 1;\n", "v2 = q/y2;\n", "F2 = v2/(g*y2)**0.5; \t\t\t\t#<1\n", "y2 = (y1/2)*((1+8*F1**2)**0.5-1);\n", "de = y2-1;\n", "le = 5*(y2-y1);\n", "de = round(de*1000)/1000;\n", "le = round(le*10)/10;\n", "\n", "# Results\n", "print \"stilling bamath.sin should be depressed by %.2f m.\"%(de);\n", "print \"length of stilling bamath.sin = %.2f m.\"%(le);\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "stilling bamath.sin should be depressed by 0.58 m.\n", "length of stilling bamath.sin = 7.50 m.\n" ] } ], "prompt_number": 7 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 11.7 pg : 563" ] }, { "cell_type": "code", "collapsed": false, "input": [ "import math \n", "\n", "\n", "\t\t\t\t\n", "#Given\n", "q = 7.83; \t\t\t\t#discharge through spillway\n", "w = 12.5; \t\t\t\t#width of fall\n", "d = 2.; \t\t\t\t#depth of water in downstream\n", "g = 9.8;\n", "\n", "y1 = 0.5;\n", "v1 = q/y1;\n", "F1 = v1/(g*y1)**0.5;\n", "\n", "#F>1,flow is super-critical\n", "\n", "# Calculations\n", "v2 = q/d;\n", "F2 = v2/(g*d)**0.5;\n", "y2 = (y1/2)*((1+8*F1**2)**0.5-1);\n", "de = y2-d;\n", "le = 5*(y2-y1);\n", "de = round(de*100)/100;\n", "le = round(le*10)/10;\n", "\n", "# Results\n", "print \"stilling bamath.sin should be depressed by %.2f m.\"%(de);\n", "print \"length of stilling bamath.sin = %.2f m.\"%(le); \n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "stilling bamath.sin should be depressed by 2.76 m.\n", "length of stilling bamath.sin = 21.30 m.\n" ] } ], "prompt_number": 9 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 11.8 pg : 564" ] }, { "cell_type": "code", "collapsed": false, "input": [ "import math \n", "\n", "\n", "\t\t\t\t\n", "#Given\n", "Ag = 5*2.5; \t\t\t\t#area of gate\n", "miu = 0.25; \t\t\t\t#coefficient of friction\n", "w = 0.5; \t\t\t\t#weigth of gate\n", "h = 2; \t\t\t\t#head of water over crest\n", "g = 9.81; \t\t\t\t#acceleration due to gravity\n", "gamma_w = 1000; \t\t\t\t#unit weigth of water\n", "\n", "\n", "# Calculations\n", "m = w*g*1000;\n", "F = gamma_w*Ag*h*h*g/10;\n", "ff = miu*F;\n", "tf = (m+ff)/1000;\n", "\n", "# Results\n", "print \"force to be exerted to lift the gate = %.2f kN.\"%(tf);\n", "\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "force to be exerted to lift the gate = 17.17 kN.\n" ] } ], "prompt_number": 10 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 11.9 pg : 564" ] }, { "cell_type": "code", "collapsed": false, "input": [ "import math \n", "\n", "\n", "\t\t\t\t\n", "#Given\n", "q = 19; \t\t\t\t#dischrge through spillway\n", "E = 1; \t\t\t\t#energy loss\n", "\n", "\t\t\t\t#from energy loss equation;E = (y2-y1)**3/4y2y1; and solving it we get\n", "\t\t\t\t#x = 0.5*(-1+(1+294.39*(x-1)**9/64*x**3))\n", "\t\t\t\t#by trial and error method x = 2.806\n", "x = 2.806;\n", "y1 = 4*x/(x-1)**3;\n", "y2 = x*y1;\n", "y1 = round(y1*1000)/1000;\n", "y2 = round(y2*1000)/1000;\n", "print \"depth of flow at both end of jumps = %.2f m and %.2f m. respectively.\"%(y1,y2);\n", "\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "depth of flow at both end of jumps = 1.91 m and 5.35 m. respectively.\n" ] } ], "prompt_number": 11 } ], "metadata": {} } ] }