{ "metadata": { "name": "", "signature": "sha256:8ebaaa4d9fc694c6b4303418dc1faf3eef2d83f1637b122e018c6c5eac0aba66" }, "nbformat": 3, "nbformat_minor": 0, "worksheets": [ { "cells": [ { "cell_type": "heading", "level": 1, "metadata": {}, "source": [ "Chapter 10 - Dynamic lift" ] }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 2a - Pg 427" ] }, { "cell_type": "code", "collapsed": false, "input": [ "#calculate the max. theoretical propulsive force\n", "#Initialization of variables\n", "import math\n", "vel=50. #mph\n", "w=240. #rpm\n", "r0=3. #ft\n", "L=30. #ft\n", "rho=0.00230 #slug/ft^2\n", "theta=30*math.pi/180. #radians\n", "#calculations\n", "V=vel*5280./3600.\n", "T=2*math.pi*r0*r0 *w*2*math.pi/60.\n", "Fl=rho*V*T*L\n", "F=r0*Fl*math.cos(theta)\n", "#results\n", "print '%s %d %s' %(\"Max. theoretical porpulsive force =\",F,\"lb\")\n", "print '%s' %(\"The answers are a bit different from textbook due to rounding off error\")" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Max. theoretical porpulsive force = 18683 lb\n", "The answers are a bit different from textbook due to rounding off error\n" ] } ], "prompt_number": 1 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 2b - Pg 428" ] }, { "cell_type": "code", "collapsed": false, "input": [ "#calculate the force required for the operation\n", "#Initialization of variables\n", "import math\n", "vel=50. #mph\n", "w=240. #rpm\n", "r0=3. #ft\n", "L=30. #ft\n", "rho=0.00230 #slug/ft^2\n", "theta=30*math.pi/180. #radians\n", "Cl=2\n", "Cd=1\n", "#calculations\n", "vc=r0*w\n", "V=vel*5280./3600.\n", "vr=vc/V\n", "A=2*r0*L\n", "Fl=Cl*A*0.5*rho*V*V \n", "Fd=Cd*A*0.5*rho*V*V\n", "F=r0*(Fl*math.cos(theta) + Fd*math.sin(theta))\n", "#results\n", "print '%s %d %s' %(\"Force required =\",F,\"lb\")\n", "print '%s' %(\"The answers are a bit different from textbook due to rounding off error\")" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Force required = 7454 lb\n", "The answers are a bit different from textbook due to rounding off error\n" ] } ], "prompt_number": 2 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 3a - Pg 432" ] }, { "cell_type": "code", "collapsed": false, "input": [ "#calculate the boundary circulation\n", "#Initialization of variables\n", "W=7500 #pounds\n", "rho=0.00230\n", "V=175*5280/3600 #ft/s\n", "B=50\n", "#calculations\n", "T=W/(rho*V*B)\n", "#results\n", "print '%s %d %s' %(\"Boundary circulation =\",T,\"ft^2/s\")\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Boundary circulation = 254 ft^2/s\n" ] } ], "prompt_number": 4 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 3b - Pg 433" ] }, { "cell_type": "code", "collapsed": false, "input": [ "#calculate the horsepower required for the operation\n", "#Initialization of variables\n", "W=7500. #pounds\n", "rho=0.00230\n", "V=175*5280./3600. #ft/s\n", "B=50.\n", "A=350. #ft^2\n", "#calculations\n", "Cl=W/(A*0.5*rho*V*V)\n", "Cd=0.03\n", "Fd=Cd*A*0.5*rho*V*V \n", "hp=Fd*V/550.\n", "#results\n", "print '%s %d %s' %(\"Horsepower required =\",hp,\"hp\")" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Horsepower required = 371 hp\n" ] } ], "prompt_number": 5 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 4 - Pg 437" ] }, { "cell_type": "code", "collapsed": false, "input": [ "#calculate the horsepower required for the operation\n", "#Initialization of variables\n", "import math\n", "Fl=7500. #pounds\n", "rho=0.00230\n", "V=175*5280./3600. #ft/s\n", "B=50\n", "A=350 #ft^2\n", "#calculations\n", "Vi=2*Fl/(math.pi*rho*V*B*B)\n", "Cl=Fl/(A*0.5*rho*V*V)\n", "Cdi=Cl*Vi/(V)\n", "Fdi=Cdi*A*0.5*rho*V*V\n", "hp=Fdi*V/550\n", "#results\n", "print '%s %.1f %s' %(\"Horsepower required =\",hp,\"hp\")" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Horsepower required = 44.1 hp\n" ] } ], "prompt_number": 6 } ], "metadata": {} } ] }