# A script to compute the viscosity and thermal conductivity
# of air (as a mixture of N2 and O2) from 200 -- 20000 K.
#
# Author: Peter J. and Rowan J. Gollan
# Date: 2019-11-21
#
# To run this script:
# $ prep-gas thermally-perfect-N2-O2.inp thermally-perfect-N2-O2.lua
# $ python3 transport-properties-for-air.py
#
from eilmer.gas import GasModel, GasState
gasModelFile = 'thermally-perfect-N2-O2.lua'
gmodel = GasModel(gasModelFile)
gs = GasState(gmodel)
gs.p = 1.0e5 # Pa
gs.massf = {"N2":0.78, "O2":0.22} # approximation for the composition of air
outputFile = 'trans-props-air.dat'
print("Opening file for writing: %s" % outputFile)
f = open(outputFile, "w")
f.write("# 1:T[K] 2:mu[Pa.s] 3:k[W/(m.K)]\n")
lowT = 200.0
dT = 100.0
for i in range(199):
gs.T = dT*i + lowT
gs.update_thermo_from_pT()
gs.update_trans_coeffs()
# ideal-shock-test.py
#
# $ prep-gas ideal-air.inp ideal-air-gas-model.lua
# $ python3 ideal-shock-test.py
#
# PJ, 2019-11-28
#
import math
from eilmer.gas import GasModel, GasState, GasFlow
gmodel = GasModel('ideal-air-gas-model.lua')
state1 = GasState(gmodel)
state1.p = 125.0e3 # Pa
state1.T = 300.0 # K
state1.update_thermo_from_pT()
state1.update_sound_speed()
print("state1: %s" % state1)
print("normal shock (in ideal gas), given shock speed")
vs = 2414.0
state2 = GasState(gmodel)
flow = GasFlow(gmodel)
v2, vg = flow.ideal_shock(state1, vs, state2)
print("v2=%g vg=%g" % (v2, vg))
print("state2: %s" % state2)
# Started with Rowan's description in Section 4.4 of his PhD thesis
# and then built upon the gas-model API, the kinetics API,
# the quasi-1D gas flow functions, and linearized 1D flow constraints
# as used in the duct-with-hydrogen-combustion example.
# This is a proof of concept code, that you will probably adapt.
#
# Typical use:
# $ python3 poshax.py
#
#------------------------------------------------------------------
from eilmer.gas import GasModel, GasState, GasFlow, ThermochemicalReactor
debug = False
print("Initialise a gas model.")
print("air 7 species Gupta-et-al reactions")
gmodel = GasModel("air-7sp-gas-model.lua")
nsp = gmodel.n_species
nmodes = gmodel.n_modes
if debug: print("nsp=", nsp, " nmodes=", nmodes, " gmodel=", gmodel)
reactor = ThermochemicalReactor(gmodel, "air-7sp-chemistry.lua")
# The example here matches the case discussed on page 63 of the thesis.
state1 = GasState(gmodel)
state1.p = 133.3 # Pa
state1.T = 300.0 # degree K
state1.massf = {"N2": 0.78, "O2": 0.22}
print("Free stream conditions, before the shock.")
state1.update_thermo_from_pT()
state1.update_sound_speed()
print(" state1: %s" % state1)
mach1 = 12.28
v1 = mach1 * state1.a
# $ cp ${DGD_REPO}/src/gas/sample-data/cea-air13species-gas-model.lua .
# $ python3 conical-shock-test.py
#
# PJ, 2019-12-01
#
import math
def approxEqual(a, b):
result = math.isclose(a, b, rel_tol=1.0e-2, abs_tol=1.0e-5)
# print("a=",a, "b=",b, "rel=",(a-b)/b, "abs=",a-b, "result=",result)
return result
from eilmer.gas import GasModel, GasState, GasFlow
m1 = 1.5
print("Conical-shock demo for m1=%g" % m1)
gmodel = GasModel('cea-air13species-gas-model.lua')
state1 = GasState(gmodel)
state1.p = 100.0e3 # Pa
state1.T = 300.0 # K ideal air, not high T
state1.update_thermo_from_pT()
state1.update_sound_speed()
print("state1: %s" % state1)
v1 = m1*state1.a
print("v1=%g" % v1)
beta = 45.0 * math.pi/180.0
print(" given beta(degrees)=%g" % (beta*180/math.pi))
state_c = GasState(gmodel)
flow = GasFlow(gmodel)
theta_c, v_c = flow.theta_cone(state1, v1, beta, state_c)
print(" theta_c=%g degrees" % (theta_c*180/math.pi))
# Started with Rowan's description in Section 4.4 of his PhD thesis
# and then built upon the gas-model API, the kinetics API,
# the quasi-1D gas flow functions, and linearized 1D flow constraints
# as used in the duct-with-hydrogen-combustion example.
# This is a proof of concept code, that you will probably adapt.
#
# Typical use:
# $ python3 co2_scheme_validation.py
#
#------------------------------------------------------------------
from eilmer.gas import GasModel, GasState, GasFlow, ThermochemicalReactor
debug = False
print("Initialise a gas model.")
print("Park et al mars atmosphere reaction scheme.")
gmodel = GasModel("mars-atm-with-ions.lua")
nsp = gmodel.n_species
nmodes = gmodel.n_modes
if debug: print("nsp=", nsp, " nmodes=", nmodes, " gmodel=", gmodel)
reactor = ThermochemicalReactor(gmodel, "mars-atm-with-ions-chemistry.lua")
# The example here matches the case on p.17 of Park's publication
v1 = 8000
state1 = GasState(gmodel)
state1.rho = 0.15 * 101300 / v1**2 # freestream density according to Park to keep p after the shock at 0.15atm
print("Free stream desnity:", state1.rho)
state1.T = 210.0 # K, Mars surface temp
state1.massf = {
"CO2": 0.9664,
"N2": 0.0174,
"Ar": 0.0147,
"O2": 0.001,
du = u0 * tol
gas1.u = u0 + du
gas1.update_thermo_from_rhou()
dpdu = (gas1.p - p0) / du
#
return dpdrho, dpdu
#------------------------------------------------------------------
# Start the main script...
debug = False
print("# Reacting pipe flow -- Bittker-Scullin test case 3.")
print(sample_header)
# Gas model setup
gmodel = GasModel("h2-o2-n2-9sp.lua")
nsp = gmodel.n_species
nmodes = gmodel.n_modes
if debug: print("nsp=", nsp, " nmodes=", nmodes, " gmodel=", gmodel)
print("# Gas properties at the start of the pipe.")
gas0 = GasState(gmodel)
gas0.p = 96.87e3 # Pa
x = 0.0 # m (inlet of pipe)
v = 4551.73 # m/s
gas0.T = 1559.0 # degree K
gas0.molef = {"O2": 0.1480, "N2": 0.5562, "H2": 0.2958}
gas0.update_thermo_from_pT()
dt_suggest = 1.0e-8 # suggested starting time-step for chemistry updater
print(sample_data(x, v, gas0, dt_suggest))
#! /usr/bin/env python3
# gas_demo.py
#
# Try out the GasModel and GasState CFFI wrappers.
#
# You will need to "make install" the loadable library
# and then invoke this script from a location where
# the gas-model Lua file is visible, as given by the path below.
#
# PJ 2019-07-24 direct use of FFI
# 2019-07-25 using Pythonic wrapper
#
from eilmer.gas import GasModel, GasState
gmodel = GasModel("ideal-air-gas-model.lua")
print("gmodel=", gmodel)
print("n_species=", gmodel.n_species, ", n_modes=", gmodel.n_modes)
print("species_names=", gmodel.species_names)
print("mol_masses=", gmodel.mol_masses)
gs = GasState(gmodel)
print("freshly minted gs=", gs)
gs.rho=1.1; gs.p=1.0e5; gs.T=300.0; gs.u=1.44e6; gs.massf=[1.0]
print("after setting some values")
print(" gs.rho=%g p=%g T=%g u=%g massf=%s a=%g k=%g mu=%g" %
(gs.rho, gs.p, gs.T, gs.u, gs.massf, gs.a, gs.k, gs.mu))
gmodel.update_thermo_from_pT(gs) # the way that we do the update in D
gmodel.update_sound_speed(gs) # not necessary from Python but is available
gmodel.update_trans_coeffs(gs)
print("after update thermo from pT")
print(" gs.rho=%g p=%g T=%g u=%g massf=%s a=%g k=%g mu=%g" %
default="302.0",
help="Temperature (degree K) at which to evaluate the internal energy offset.")
(options, args) = parser.parse_args()
if options.tableName == None or options.gasModelFile == None:
parser.print_help()
print("")
print("Example 1: build-uniform-lut --gas-model=cea-air5species-gas-model.lua"+
" --table-name=air5species")
print("Example 2: build-uniform-lut --gas-model=cea-air13species-gas-model.lua"+
" --table-name=air13species --bounds=\"500,20000,-6.0,2.0\"")
print("Example 3: build-uniform-lut --gas-model=cea-co2-gas-model.lua"+
" --table-name=co2 --T-for-offset=650.0 --bounds=\"1000.0,20000,-6.0,2.0\"")
print("Example 4: build-uniform-lut --gas-model=cea-co2-ions-gas-model.lua"+
" --table-name=co2-ions --T-for-offset=1000.0 --bounds=\"1000.0,20000,-6.0,2.0\"")
print("")
print("Sometimes CEA2 has problems and the table will fail to build.")
print("The best approach to fixing the problem seems to be to raise")
print("the lower temperatures, as shown in examples 2, 3 and 4 (above).")
sys.exit()
T_min, T_max, log_rho_min, log_rho_max = [float(item) for item in options.bounds.split(',')]
T_for_offset = float(options.T_for_offset)
print("Density, Temperature ranges:")
print(" log_rho_min=", log_rho_min, "log_rho_max=", log_rho_max)
print(" T_min=", T_min, "T_max=", T_max)
print("Building table for gas model:", options.gasModelFile)
gmodel = GasModel(options.gasModelFile)
assert gmodel.n_modes == 0, "Use only a single-temperature gas model."
gs = GasState(gmodel)
build_table(gs, options.tableName, T_min, T_max, log_rho_min, log_rho_max, T_for_offset)
print("Done.")
# fvreactor.py
# A simple fixed-volume reactor.
# PJ & RJG 2019-11-25
#
# To prepare:
# $ prep-gas nitrogen-2sp.inp nitrogen-2sp.lua
# $ prep-chem nitrogen-2sp.lua nitrogen-2sp-2r.lua chem.lua
#
# To run:
# $ python3 fvreactor.py
from eilmer.gas import GasModel, GasState, ThermochemicalReactor
gm = GasModel("nitrogen-2sp.lua")
reactor = ThermochemicalReactor(gm, "chem.lua")
gs = GasState(gm)
gs.p = 1.0e5 # Pa
gs.T = 4000.0 # degree K
gs.molef = {'N2': 2 / 3, 'N': 1 / 3}
gs.update_thermo_from_pT()
tFinal = 200.0e-6 # s
t = 0.0
dt = 1.0e-6
dtSuggest = 1.0e-11
print("# Start integration")
f = open("fvreactor.data", 'w')
f.write(
'# 1:t(s) 2:T(K) 3:p(Pa) 4:massf_N2 5:massf_N 6:conc_N2 7:conc_N\n')
f.write("%10.3e %10.3f %10.3e %20.12e %20.12e %20.12e %20.12e\n" %