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"name": "",
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"worksheets": [
{
"cells": [
{
"cell_type": "heading",
"level": 1,
"metadata": {},
"source": [
"CHAPTER07:COMPRESSIBLE FLOW SOME PRELIMINARY ASPECTS"
]
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Example E01 : Pg 222"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"# All the quantities are expressed in SI units\n",
"import math \n",
"l = 5.; # dimensions of the room\n",
"b = 7.;\n",
"h = 3.3;\n",
"V = l*b*h; # volume of the room\n",
"p = 101000.; # ambient pressure\n",
"T = 273. + 25.; # ambient temperature\n",
"R = 287.; # gas constant\n",
"gam = 1.4; # ratio of specific heats\n",
"cv = R/(gam-1.);\n",
"cp = gam*R/(gam-1.);\n",
"\n",
"# the density can by calculaled by the ideal gas law\n",
"rho = p/R/T;\n",
"\n",
"# thus the mass is given by\n",
"M = rho*V;\n",
"\n",
"# from eq.(7.6a), the internal energy per unit mass is\n",
"e = cv*T;\n",
"\n",
"# thus internal energy in the room is\n",
"E = e*M;\n",
"\n",
"# from eq.(7.6b), the enthalpy per unit mass is given by\n",
"h = cp*T;\n",
"\n",
"# Thus the enthalpy in the room is\n",
"H = M*h;\n",
"\n",
"print\"The internal energy in the room is: E =\", E/10**7\n",
"print\"The Enthalpy in the room is: H = \",H/10**7"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"The internal energy in the room is: E = 2.916375\n",
"The Enthalpy in the room is: H = 4.082925\n"
]
}
],
"prompt_number": 1
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Example E02 : Pg 223"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"# All the quantities are expressed in SI units\n",
"\n",
"p_inf = 22790.9; # ambient pressure at 36000 ft\n",
"T_inf = 217.2; # ambient temperature at 36000 ft\n",
"p = 19152; # pressure at the given point\n",
"gam = 1.4;\n",
"\n",
"# thus the temperature at the given point can be calculated by eq.(7.32) as\n",
"T = T_inf*((p/p_inf)**((gam-1)/gam));\n",
"\n",
"print\"The temperature at the given point is: T =\",T,\"K\""
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"The temperature at the given point is: T = 206.668775312 K\n"
]
}
],
"prompt_number": 2
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Example E03 : Pg 223"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"# All the quantities are expressed in SI units\n",
"\n",
"p =101000; # static pressure\n",
"T = 320; # static temperature\n",
"v = 1000; # velocity\n",
"gam = 1.4; # ratio of specific heats\n",
"R = 287; # universal gas constant\n",
"cp = gam*R/(gam-1); # specific heat at constant pressure\n",
"\n",
"# from eq.(7.54), the total temperature is given by\n",
"T0 = T + (v**2)/2/cp;\n",
"\n",
"# from eq.(7.32),the total pressure is given by\n",
"p0 = p*((T0/T)**(gam/(gam-1)));\n",
"\n",
"p0_atm = p0/101000;\n",
"\n",
"\n",
"print\"The total temperature and pressure are given by: T0 =\",T0,\"K\"\n",
"print\"P0 =\",p0_atm,\"atm\""
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"The total temperature and pressure are given by: T0 = 817.760079642 K\n",
"P0 = 26.678766535 atm\n"
]
}
],
"prompt_number": 3
}
],
"metadata": {}
}
]
}
|
