/usr/share/pyshared/gastables/NormalShock.py is in python-gastables 0.3-2.
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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 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 | """ Python module for properties across a normal shock in perfect gases
Assumptions:
1) One dimensional flow
2) Constant area duct
3) Perfect gas with constant specific heat 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 *
from Isentropic import Isentropic
class NormalShock:
def __init__(self, g=1.4):
""" g is the value of gamma (ratio of specific heats), default = 1.4
"""
self.g = 1.4
self.Isentropic = Isentropic(self.g)
def get_My_from_Mx(self, Mx):
"""Returns Mach No My behind a normal shock from Mach No Mx ahead of the shock"""
if Mx <= 1:
raise Exception("Mach No ahead of ths shock Mx should be greater than 1")
else:
return sqrt((2/(self.g-1) + Mx**2)/(2*self.g/(self.g-1)*Mx**2 -1))
def get_Py_by_Px_from_Mx(self, Mx):
"""Returns py/px across a normal shock from Mx """
if Mx <= 1:
raise Exception("Mach No ahead of ths shock Mx should be greater than 1")
else:
return 2*self.g/(self.g+1)* Mx**2 - (self.g-1)/(self.g+1)
def get_Ty_by_Tx_from_Mx(self, Mx):
"""Returns Ty/Tx across a normal shock from Mx """
if Mx <= 1:
raise Exception("Mach No ahead of ths shock Mx should be greater than 1")
else:
return (1 + (self.g-1)*0.5* Mx**2)*(2*self.g/(self.g-1)*Mx**2 - 1)/((self.g+1)**2/(self.g-1)*0.5* Mx**2)
def get_rhoy_by_rhox_from_Mx(self, Mx):
"""Returns rhoy/rhox across a normal shock from Mx"""
if Mx <= 1:
raise Exception("Mach No ahead of ths shock Mx should be greater than 1")
else:
return self.get_Py_by_Px_from_Mx(Mx) / self.get_Ty_by_Tx_from_Mx(Mx)
def get_Poy_by_Pox_from_Mx(self, Mx):
"""Returns poy/pox across a normal shock from Mx"""
if Mx <= 1:
raise Exception("Mach No ahead of ths shock Mx should be greater than 1")
else:
My = self.get_My_from_Mx(Mx)
return self.Isentropic.get_P_by_Po_from_M(Mx) * self.get_Py_by_Px_from_Mx(Mx) / self.Isentropic.get_P_by_Po_from_M(My)
def get_Poy_by_Px_from_Mx(self, Mx):
"""Returns poy/px across a normal shock from Mx"""
if Mx <= 1:
raise Exception("Mach No ahead of ths shock Mx should be greater than 1")
else:
My = self.get_My_from_Mx(Mx)
return self.get_Py_by_Px_from_Mx(Mx) / self.Isentropic.get_P_by_Po_from_M(My)
def get_Mx_from_My(self, My):
"""Returns Mach No Mx ahead of a normal shock from Mach No My behind the shock"""
if My >= 1.0 or My <= sqrt((self.g-1)/self.g * 0.5):
raise Exception("Mach No behind a normal shock My should be between %s and 1.0" % str(sqrt((self.g-1)/self.g * 0.5)))
else:
return sqrt((1 + (self.g-1)* 0.5 * My**2)/(self.g * My**2 - (self.g-1)*0.5))
def get_Py_by_Px_from_My(self, My):
"""Returns py/px across a normal shock from My """
if My >= 1.0 or My <= sqrt((self.g-1)/self.g * 0.5):
raise Exception("Mach No behind a normal shock My should be between %s and 1.0" % str(sqrt((self.g-1)/self.g * 0.5)))
else :
Mx = self.get_Mx_from_My(My)
return self.get_Py_by_Px_from_Mx(Mx)
def get_Ty_by_Tx_from_My(self, My):
"""Returns Ty/Tx across a normal shock from My """
if My >= 1.0 or My <= sqrt((self.g-1)/self.g * 0.5):
raise Exception("Mach No behind a normal shock My should be between %s and 1.0" % str(sqrt((self.g-1)/self.g * 0.5)))
else :
Mx = self.get_Mx_from_My(My)
return self.get_Ty_by_Tx_from_Mx(Mx)
def get_rhoy_by_rhox_from_My(self, My):
"""Returns rhoy/rhox across a normal shock from My"""
if My >= 1.0 or My <= sqrt((self.g-1)/self.g * 0.5):
raise Exception("Mach No behind a normal shock My should be between %s and 1.0" % str(sqrt((self.g-1)/self.g * 0.5)))
else :
Mx = self.get_Mx_from_My(My)
return self.get_rhoy_by_rhox_from_Mx(Mx)
def get_Poy_by_Pox_from_My(self, My):
"""Returns poy/pox across a normal shock from My"""
if My >= 1.0 or My <= sqrt((self.g-1)/self.g * 0.5):
raise Exception("Mach No behind a normal shock My should be between %s and 1.0" % str(sqrt((self.g-1)/self.g * 0.5)))
else :
Mx = self.get_Mx_from_My(My)
return self.get_Poy_by_Pox_from_Mx(Mx)
def get_Poy_by_Px_from_My(self, My):
"""Returns poy/px across a normal shock from My"""
if My >= 1.0 or My <= sqrt((self.g-1)/self.g * 0.5):
raise Exception("Mach No behind a normal shock My should be between %s and 1.0" % str(sqrt((self.g-1)/self.g * 0.5)))
else :
Mx = self.get_Mx_from_My(My)
return self.get_Poy_by_Px_from_Mx(Mx)
def get_Mx_from_Ty_by_Tx(self, Ty_by_Tx):
"""Returns Mx from Ty/Tx equal to Ty_by_Tx"""
if Ty_by_Tx <= 1.0:
raise Exception("Ty/Tx must be greater than 1")
else:
a = 2*self.g*(self.g-1)
b = 4*self.g - (self.g-1)**2 - Ty_by_Tx * (self.g+1)**2
c = -2*(self.g-1)
return sqrt((-b + sqrt(b**2 - 4*a*c))/a *0.5)
def get_My_from_Ty_by_Tx(Self, Ty_by_Tx):
"""Returns Mx from Ty/Tx equal to Ty_by_Tx"""
if Ty_by_Tx <= 1.0:
raise Exception("Ty/Tx must be greater than 1")
else:
Mx = self.get_Mx_from_Ty_by_Tx(Ty_by_Tx)
return self.get_My_from_Mx(Mx)
def get_Py_by_Px_from_Ty_by_Tx(self, Ty_by_Tx):
"""Returns Py/Px from Ty/Tx equal to Ty_by_Tx"""
if Ty_by_Tx <= 1.0:
raise Exception("Ty/Tx must be greater than 1")
else:
Mx = self.get_Mx_from_Ty_by_Tx(Ty_by_Tx)
return self.get_Py_by_Px_from_Mx(Mx)
def get_Poy_by_Pox_from_Ty_by_Tx(self, Ty_by_Tx):
"""Returns poy/pox from Ty/Tx equal to Ty_by_Tx"""
if Ty_by_Tx <= 1.0:
raise Exception("Ty/Tx must be greater than 1")
else:
Mx = self.get_Mx_from_Ty_by_Tx(Ty_by_Tx)
return self.get_Poy_by_Pox_from_Mx(Mx)
def get_Poy_by_Px_from_Ty_by_Tx(self, Ty_by_Tx):
"""Returns poy/px from Ty/Tx equal to Ty_by_Tx"""
if Ty_by_Tx <= 1.0:
raise Exception("Ty/Tx must be greater than 1")
else:
Mx = self.get_Mx_from_Ty_by_Tx(Ty_by_Tx)
return self.get_Poy_by_Px_from_Mx(Mx)
def get_Mx_from_Py_by_Px(self, Py_by_Px):
"""Returns Mx from py/px equal to Py_by_Px"""
if Py_by_Px <= 1:
raise Exception("py/px must be greater than 1")
else:
return sqrt((Py_by_Px - 1)* (self.g+1)/self.g * 0.5 + 1)
def get_My_from_Py_by_Px(self, Py_by_Px):
"""Returns My from py/px equal to Py_by_Px"""
if Py_by_Px <= 1:
raise Exception("py/px must be greater than 1")
else:
Mx = self.get_Mx_from_Py_by_Px(Py_by_Px)
return self.get_My_from_Mx(Mx)
def get_Ty_by_Tx_from_Py_by_Px(self, Py_by_Px):
"""Returns Ty/Tx from py/px equal to Py_by_Px"""
if Py_by_Px <= 1:
raise Exception("py/px must be greater than 1")
else:
Mx = self.get_Mx_from_Py_by_Px(Py_by_Px)
return self.get_Ty_by_Tx_from_Mx(Mx)
def get_Poy_by_Pox_from_Py_by_Px(self, Py_by_Px):
"""Returns poy/pox from Py/Px equal to Py_by_Px"""
if Py_by_Px <= 1:
raise Exception("py/px must be greater than 1")
else:
Mx = self.get_Mx_from_Py_by_Px(Py_by_Px)
return self.get_Poy_by_Pox_from_Mx(Mx)
def get_Poy_by_Px_from_Py_by_Px(self, Py_by_Px):
"""Returns Poy/Px from Py/Px equal to Py_by_Px"""
if Py_by_Px <= 1:
raise Exception("py/px must be greater than 1")
else:
Mx = self.get_Mx_from_Py_by_Px(Py_by_Px)
return self.get_Poy_by_Px_from_Mx(Mx)
def get_Mx_from_rhoy_by_rhox(self, rhoy_by_rhox):
"""Returns Mx from rhoy/rhox equal to rhoy_by_rhox"""
if rhoy_by_rhox <=1.0 or rhoy_by_rhox >= (self.g+1)/(self.g-1):
raise Exception("rhoy/rhox should be between 1 and ",(self.g+1)/(self.g-1))
else:
return sqrt(2*rhoy_by_rhox/(self.g+1- rhoy_by_rhox*(self.g-1)))
def get_My_from_rhoy_by_rhox(self, rhoy_by_rhox):
"""Returns My from rhoy/rhox equal to rhoy_by_rhox"""
if rhoy_by_rhox <=1.0 or rhoy_by_rhox >= (self.g+1)/(self.g-1):
raise Exception("rhoy/rhox should be between 1 and ",(self.g+1)/(self.g-1))
else:
Mx = self.get_Mx_from_rhoy_by_rhox(rhoy_by_rhox)
return self.get_My_from_Mx(Mx)
def get_Ty_by_Tx_from_rhoy_by_rhox(self, rhoy_by_rhox):
"""Returns Ty/Tx from rhoy/rhox equal to rhoy_by_rhox"""
if rhoy_by_rhox <=1.0 or rhoy_by_rhox >= (self.g+1)/(self.g-1):
raise Exception("rhoy/rhox should be between 1 and ",(self.g+1)/(self.g-1))
else:
Mx = self.get_Mx_from_rhoy_by_rhox(rhoy_by_rhox)
return self.get_Ty_by_Tx_from_Mx(Mx)
def get_Poy_by_Pox_from_rhoy_by_rhox(self, rhoy_by_rhox):
"""Returns poy/pox from rhoy/rhox equal to rhoy_by_rhox"""
if rhoy_by_rhox <=1.0 or rhoy_by_rhox >= (self.g+1)/(self.g-1):
raise Exception("rhoy/rhox should be between 1 and ",(self.g+1)/(self.g-1))
else:
Mx = self.get_Mx_from_rhoy_by_rhox(rhoy_by_rhox)
return self.get_Poy_by_Pox_from_Mx(Mx)
def get_Poy_by_Px_from_rhoy_by_rhox(self, rhoy_by_rhox):
"""Returns poy/px from rhoy/rhox equal to rhoy_by_rhox"""
if rhoy_by_rhox <=1.0 or rhoy_by_rhox >= (self.g+1)/(self.g-1):
raise Exception("rhoy/rhox should be between 1 and ",(self.g+1)/(self.g-1))
else:
Mx = self.get_Mx_from_rhoy_by_rhox(rhoy_by_rhox)
return self.get_Poy_by_Px_from_Mx(Mx)
def get_Mx_from_Poy_by_Pox(self, Poy_by_Pox):
"""Returns Mx from poy/pox equal to Poy_by_Pox"""
if Poy_by_Pox <= 0 or Poy_by_Pox >= 1:
raise Exception("Poy/Pox must be between 0 and 1")
else:
return optimize.fsolve(lambda Mx: self.get_Poy_by_Pox_from_Mx(Mx) - Poy_by_Pox, 2.0)
def get_My_from_Poy_by_Pox(self, Poy_by_Pox):
"""Returns My from poy/pox equal to Poy_by_Pox"""
if Poy_by_Pox <= 0 or Poy_by_Pox >= 1:
raise Exception("Poy/Pox must be between 0 and 1")
else:
Mx = self.get_Mx_from_Poy_by_Pox(Poy_by_Pox)
return self.get_My_from_Mx(Mx)
def get_Ty_by_Tx_from_Poy_by_Pox(self, Poy_by_Pox):
"""Returns Ty/Tx from poy/pox equal to Poy_by_Pox"""
if Poy_by_Pox <= 0 or Poy_by_Pox >= 1:
raise Exception("Poy/Pox must be between 0 and 1")
else:
Mx = self.get_Mx_from_Poy_by_Pox(Poy_by_Pox)
return self.get_Ty_by_Tx_from_Mx(Mx)
def get_Py_by_Px_from_Poy_by_Pox(self, Poy_by_Pox):
"""Returns py/px from poy/pox equal to Poy_by_Pox"""
if Poy_by_Pox <= 0 or Poy_by_Pox >= 1:
raise Exception("Poy/Pox must be between 0 and 1")
else:
Mx = self.get_Mx_from_Poy_by_Pox(Poy_by_Pox)
return self.get_Py_by_Px_from_Mx(Mx)
def get_Poy_by_Px_from_Poy_by_Pox(self, Poy_by_Pox):
"""Returns poy/px from poy/pox equal to Poy_by_Pox"""
if Poy_by_Pox <= 0 or Poy_by_Pox >= 1:
raise Exception("Poy/Pox must be between 0 and 1")
else:
Mx = self.get_Mx_from_Poy_by_Pox(Poy_by_Pox)
return self.get_Poy_by_Px_from_Mx(Mx)
def get_Mx_from_Poy_by_Px(self, Poy_by_Px):
"""Returns Mx from poy/px equal to Poy_by_Px"""
if Poy_by_Px <= ((self.g+1)*0.5)**(self.g/(self.g-1)):
raise Exception("Poy/Px should be greater than",((self.g+1)*0.5)**(self.g/(self.g-1)))
else:
return optimize.fsolve(lambda Mx: self.get_Poy_by_Px_from_Mx(Mx) - Poy_by_Px, 2.0)
def get_My_from_Poy_by_Px(self, Poy_by_Px):
"""Returns My from poy/px equal to Poy_by_Px"""
if Poy_by_Px <= ((self.g+1)*0.5)**(self.g/(self.g-1)):
raise Exception("Poy/Px should be greater than",((self.g+1)*0.5)**(self.g/(self.g-1)))
else:
Mx = self.get_Mx_from_Poy_by_Px(Poy_by_Px)
return self.get_My_from_Mx(Mx)
def get_Ty_by_Tx_from_Poy_by_Px(self, Poy_by_Px):
"""Returns Mx from poy/px equal to Poy_by_Px"""
if Poy_by_Px <= ((self.g+1)*0.5)**(self.g/(self.g-1)):
raise Exception("Poy/Px should be greater than",((self.g+1)*0.5)**(self.g/(self.g-1)))
else:
Mx = self.get_Mx_from_Poy_by_Px(Poy_by_Px)
return self.get_Ty_by_Tx_from_Mx(Mx)
def get_Py_by_Px_from_Poy_by_Px(self, Poy_by_Px):
"""Returns py/px from poy/px equal to Poy_Px"""
if Poy_by_Px <= ((self.g+1)*0.5)**(self.g/(self.g-1)):
raise Exception("Poy/Px should be greater than",((self.g+1)*0.5)**(self.g/(self.g-1)))
else:
Mx = self.get_Mx_from_Poy_by_Px(Poy_by_Px)
return self.get_Py_by_Px_from_Mx(Mx)
def get_Poy_by_Pox_from_Poy_by_Px(self, Poy_by_Px):
"""Returns poy/pox from poy/px equal to Poy_by_Px """
if Poy_by_Px <= ((self.g+1)*0.5)**(self.g/(self.g-1)):
raise Exception("Poy/Px should be greater than",((self.g+1)*0.5)**(self.g/(self.g-1)))
else:
Mx = self.get_Mx_from_Poy_by_Px(Poy_by_Px)
return self.get_Poy_by_Pox_from_Mx(Mx)
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