/usr/lib/python2.7/dist-packages/gastables/FannoFlow.py is in python-gastables 0.3-2.2.
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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 | """Python module for flow properties of perfect gases with friction
In Fanno flow, friction in the passage leads to increase in entropy
and takes the process towards the choking conditions, (M = M* = 1).
Assumptions:
1) One dimensional flow with friction
2) Constant area duct
3) perfect gas with constant specific heats and molecular weights
4) adiabatic flow
"""
"""
* Copyright (C) 2006 Varun Hiremath.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version 2
* of the License, or (at your option) any later version.
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
* Authors: Varun Hiremath, Venkattraman A
* Version 0.2
"""
from scipy import optimize
from math import *
class FannoFlow :
def __init__(self, g= 1.4):
""" g is the value of gamma (ratio of specific heats), default = 1.4
"""
self.g = g
def get_P_by_Pstar_from_M(self,M):
if M < 0:
raise Exception('Value of M negative. M value should be positive')
else:
return ((self.g+1)/2/(1+ (self.g -1)/ 2*M**2))**(0.5)/M
def get_rho_by_rhostar_from_M(self,M):
if M < 0:
raise Exception('Value of M negative. M value should be positive')
else:
return ((self.g+1)/2/(1+ (self.g -1)/ 2*M**2))**(0.5)*M
def get_T_by_Tstar_from_M(self,M):
if M < 0:
raise Exception('Value of M negative. M value should be positive')
else:
return (self.g+1)/2/(1+ (self.g -1)/ 2*M**2)
def get_Po_by_Postar_from_M(self,M):
if M < 0:
raise Exception('Value of M negative. M value should be positive')
else:
return (2*(1+(self.g-1)/2*M**2)/(self.g+1))**((self.g+1)/(self.g-1)/2)/M
def get_F_by_Fstar_from_M(self,M):
if M < 0:
raise Exception('Value of M negative. M value should be positive')
else:
return (1+self.g*M**2)/M/(2*(self.g+1)*(1+(self.g-1)/2*M**2))**0.5
def get_4fLmax_by_D_from_M(self,M):
if M < 0:
raise Exception('Value of M negative. M value should be positive')
else:
return (1-M**2)/self.g/M**2 + (self.g+1)/2/self.g*log((self.g+1)*M**2/2/(1+(self.g-1)/2*M**2))
def get_M_from_P_by_Pstar(self,P_by_Pstar):
if P_by_Pstar <= 0 or P_by_Pstar > self.get_P_by_Pstar_from_M(0.0001):
raise Exception('Value of P/Pstar should be greater than 0 and less than %s' % self.get_P_by_Pstar_from_M(0.0001))
else:
return optimize.fsolve(lambda M : self.get_P_by_Pstar_from_M(M) - P_by_Pstar, 0.001)
def get_rho_by_rhostar_from_P_by_Pstar(self,P_by_Pstar):
M = self.get_M_from_P_by_Pstar(P_by_Pstar)
return self.get_rho_by_rhostar_from_M(M)
def get_T_by_Tstar_from_P_by_Pstar(self,P_by_Pstar):
M = self.get_M_from_P_by_Pstar(P_by_Pstar)
return self.get_T_by_Tstar_from_M(M)
def get_Po_by_Postar_from_P_by_Pstar(self,P_by_Pstar):
M = self.get_M_from_P_by_Pstar(P_by_Pstar)
return self.get_Po_by_Postar_from_M(M)
def get_F_by_Fstar_from_P_by_Pstar(self,P_by_Pstar):
M = self.get_M_from_P_by_Pstar(P_by_Pstar)
return self.get_F_by_Fstar_from_M(M)
def get_4fLmax_by_D_from_P_by_Pstar(self,P_by_Pstar):
M = self.get_M_from_P_by_Pstar(P_by_Pstar)
return self.get_4fLmax_by_D_from_M(M)
def get_M_from_rho_by_rhostar(self,rho_by_rhostar):
if rho_by_rhostar <= 0 or rho_by_rhostar > self.get_rho_by_rhostar_from_M(100.0):
raise Exception('Value of rho/rhostar should be greater than 0 and less than %s' % self.get_rho_by_rhostar_from_M(100.0))
else:
return optimize.fsolve(lambda M : self.get_rho_by_rhostar_from_M(M) - rho_by_rhostar, 0.001)
def get_P_by_Pstar_from_rho_by_rhostar(self,rho_by_rhostar):
M = self.get_M_from_rho_by_rhostar(rho_by_rhostar)
return self.get_P_by_Pstar_from_M(M)
def get_T_by_Tstar_from_rho_by_rhostar(self,rho_by_rhostar):
M = self.get_M_from_rho_by_rhostar(rho_by_rhostar)
return self.get_T_by_Tstar_from_M(M)
def get_Po_by_Postar_from_rho_by_rhostar(self,rho_by_rhostar):
M = self.get_M_from_rho_by_rhostar(rho_by_rhostar)
return self.get_Po_by_Postar_from_M(M)
def get_F_by_Fstar_from_rho_by_rhostar(self,rho_by_rhostar):
M = self.get_M_from_rho_by_rhostar(rho_by_rhostar)
return self.get_F_by_Fstar_from_M(M)
def get_4fLmax_by_D_from_rho_by_rhostar(self,rho_by_rhostar):
M = self.get_M_from_rho_by_rhostar(rho_by_rhostar)
return self.get_4fLmax_by_D_from_M(M)
def get_M_from_T_by_Tstar(self,T_by_Tstar):
if T_by_Tstar > self.get_T_by_Tstar_from_M(0.0001):
raise Exception("Value of T/T* should be less than %s" % self.get_T_by_Tstar_from_M(0.0001))
else:
return optimize.fsolve(lambda M : self.get_T_by_Tstar_from_M(M) - T_by_Tstar, 0.0001)
def get_P_by_Pstar_from_T_by_Tstar(self,T_by_Tstar):
M = self.get_M_from_T_by_Tstar(T_by_Tstar)
return self.get_P_by_Pstar_from_M(M)
def get_rho_by_rhostar_from_T_by_Tstar(self,T_by_Tstar):
M = self.get_M_from_T_by_Tstar(T_by_Tstar)
return self.get_rho_by_rhostar_from_M(M)
def get_Po_by_Postar_from_T_by_Tstar(self,T_by_Tstar):
M = self.get_M_from_T_by_Tstar(T_by_Tstar)
return self.get_Po_By_Postar_from_M(M)
def get_F_by_Fstar_from_T_by_Tstar(self,T_by_Tstar):
M = self.get_M_from_T_by_Tstar(T_by_Tstar)
return self.get_F_by_Fstar_from_M(M)
def get_4fLmax_by_D_from_T_by_Tstar(self,T_by_Tstar):
M = self.get_M_from_T_by_Tstar(T_by_Tstar)
return self.get_4fLmax_by_D_from_M(M)
def get_M_from_Po_by_Postar(self,Po_by_Postar):
return (optimize.bisect(lambda M : self.get_Po_by_Postar_from_M(M) - Po_by_Postar, 0.001, 1.0),optimize.bisect(lambda M : self.get_Po_by_Postar_from_M(M) - Po_by_Postar, 1.0, 100))
def get_M_from_F_by_Fstar(self,F_by_Fstar):
return (optimize.bisect(lambda M : self.get_F_by_Fstar_from_M(M) - F_by_Fstar, 0.001, 1.0),optimize.bisect(lambda M : self.get_F_by_Fstar_from_M(M) - F_by_Fstar, 1.0, 100))
def get_M_from_4fLmax_by_D(self,fLmax_by_D):
return (optimize.bisect(lambda M : self.get_4fLmax_by_D_from_M(M) - fLmax_by_D, 0.001, 1.0),optimize.bisect(lambda M : self.get_4fLmax_by_D_from_M(M) - fLmax_by_D, 1.0, 100))
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