def calc_cjspeed(self):
if self.cjspeed is False:
# Calculation for the Chapman-Jouget speeds
self.cjspeed = CJspeed(P1=self.P1, T1=self.T1, q=self.q, mech=self.mech, fullOutput=False)
return self.cjspeed
def Errorcontour(diluent='Ar', mechanism='GRI_red2'):
# initialise mushroompy
study = m1d.DetonationTube()
# get all the data folder names from the 1D_AMROC_data folder
pathcaselist = glob.glob(f'{study.simdata_path}/*')
caselist = [os.path.basename(i) for i in pathcaselist]
# extract initial conditions from cases
pdriver = []
pdriven = []
dilmoles = []
error = []
desiredmech = diluent + '_' + mechanism
for case in caselist:
# get a list of the available mechanism folders inside the particular case folder
pathmechanismlist = glob.glob(f'{study.simdata_path}/{case}/*')
mechanismlist = [os.path.basename(i) for i in pathmechanismlist]
# filter for the desired mechanism/diluent combination
for mech in mechanismlist:
if mech == desiredmech:
pr, pn, dm, _ = case.split('_')
if pr != '10' and pr != '20':
pdriver.append(int(pr))
pdriven.append(int(pn))
dilmoles.append(int(dm))
# generate theoretical cj speeds for each case
P1 = float(pn)*1000
q = q = 'C2H4:1. O2:3 ' + diluent + ':' + dm
cj = CJspeed(P1=P1, T1=298., q=q, mech='gri30_highT.cti', fullOutput=False)
# get all the data for the relevant case
study.case_read(pressurestudy = case)
# calculate velocity using Rayleigh line equation
vdic = rayleighMethodMax(study, [case], [desiredmech])
# Find index of position x=300cm
xtarget = 300
lst = list(vdic[case][desiredmech][0])
closest = lst[min(range(len(lst)), key = lambda i: abs(lst[i]-xtarget))]
k = lst.index(closest)
# average velocity from x = 300cm onwards
vray = statistics.mean(list(vdic[case][desiredmech][1])[k:])
err = abs( (vray-cj)/cj*100 )
error.append(err)
# generate array of weighted average pressures
wp = np.array([pdriver[i]*50/350+pdriven[i]*300/350 for i in range(len(pdriver))])
# converd molar fractions into percentages
dperc = np.array([mpu.mol2perc(dilmols=d) for d in dilmoles])
# plot
error = np.array(error)
fig = plt.figure()
ax1 = plt.tricontourf(wp, dperc, error, cmap='viridis')
#ax1 = plt.contourf(wp, dperc, error, cmap='viridis')
plt.colorbar(ax1)
plt.show()
def CJmethod(study, caselist, mechanismlist):
velocityDict = {}
for case in caselist:
velocityDict[case] = {}
for mechanism in mechanismlist:
finalXposition = list(study.volatilecatalogue[case][mechanism]["dat_0.txt"]["DataframeObj"]["x"])[-1]
_, p2, moles, _ = case.split('_') # pressures in kpa
dil, _, _ = mechanism.split('_')
T1 = 298 # kelvin
q = 'C2H4:1. O2:3 ' + dil + ':' + moles
mech = 'gri30_highT.cti'
cj = CJspeed(P1=int(p2)*1000, T1=T1, q=q, mech=mech, fullOutput=False)
xvalues = np.linspace(0,finalXposition,10)
cjvalues = np.zeros(10)
for i in range(len(cjvalues)):
cjvalues[i] = cj
velocityDict[case][mechanism] = np.array([xvalues, cjvalues])
return velocityDict
def __init__(self, P1=10000., T1=298., diluent='Ar', dilpercent=50.):
# Find the dataroot directory, or prompt user to choose one if non-existent
self.data_path = mpyconf.parse_configfile()["dataroot"]
# Python module name
self.module = os.path.basename(__file__).replace(".py", "")
# Python class name
self.classname = type(self).__name__
# Define input and output directories
self.output_path = os.path.join(self.data_path, "_output", self.module,
self.classname)
self.mushroompath = os.path.dirname(os.path.realpath(__file__))
self.input_path = os.path.join(self.mushroompath, "templates")
# Check that templates folder exists
if not os.path.exists(self.input_path):
warnmsg = f"Templates path does not exist, generating a new one: {self.input_path}\n\nPlease, provide init.dat and solver.in example files in the specified directory.\n"
warnings.warn(warnmsg)
os.makedirs(self.input_path)
# Check that the templates folder actually has templates
"""
WRITE LATER
"""
# Check that prep output folder exists
if not os.path.exists(self.output_path):
warnmsg = f"Path for {self.classname} folder does not exist, generating a new one: {self.output_path}"
# Use initial conditions to find CJ speed
self.P1 = P1
self.T1 = T1
self.diluent = diluent
self.dilpercent = dilpercent
self.dilmoles = self.perc2mol(self.dilpercent)
self.SDTmech = 'gri30_highT.cti'
self.q = 'C2H4:1. O2:3 ' + self.diluent + ':' + str(self.dilmoles)
self.cj_speed = CJspeed(self.P1,
self.T1,
self.q,
self.SDTmech,
fullOutput=False)
def CJcontour(P0=10000., Pf=100000., T=298., diluent='Ar', percent0=0., percentf=90., n=4):
mech = 'gri30_highT.cti'
# generate array of pressures
p = np.linspace(P0, Pf, n)
# generate array of dilution ratios
dil = np.linspace(percent0, percentf, n)
# generate array of cj speeds
cj = np.zeros(len(p)*len(dil))
for i in range(len(dil)):
dilmoles = mpu.perc2mol(percent=dil[i])
q = 'C2H4:1. O2:3 ' + diluent + ':' + str(dilmoles)
for j in range(len(p)):
cj[i*len(p)+j] = CJspeed(P1=p[j], T1=T, q=q, mech=mech, fullOutput=False)
# produce arrays in the proper format for contour plotting
X, Y = np.meshgrid(p, dil)
Z = cj.reshape(X.shape)
# plot
fig = plt.figure()
ax1 = plt.contourf(X, Y, Z, levels=10, cmap='viridis')
plt.colorbar(ax1)
plt.show()
from sdtoolbox.postshock import CJspeed
from sdtoolbox.postshock import PostShock_eq
import matplotlib.pyplot as plt
T1 = 295
mech = 'gri30.cti'
gas = ct.Solution(mech)
for phi in range(50, 175, 25):
P1 = []
X = 'O2:0.5, N2:1.88, H2:' + str(phi / 100)
cjspeed = []
for P in range(100000, 1250000, 250000):
gas.TPX = T1, P, X
P1.append(P / 100000)
U = CJspeed(P, T1, X, mech)
cjspeed.append(U)
plt.plot(P1, cjspeed, label="phi=%.2f" % (phi / 100))
plt.legend()
plt.xlabel('Initial pressure [bar]')
plt.ylabel('CJ speed [m/s]')
plt.title('Cj detonation speed of hydrogen-air mixture', fontweight='bold')
plt.grid()
plt.savefig('hydrogen_cjspeed(P1).png', dpi=1000)
plt.show()
for phi in range(50, 175, 25):
P1 = []
X = 'O2:0.5, N2:1.88, H2:' + str(phi / 100)
PostShock_T = []
driver_gas.equilibrate('UV')
P4 = driver_gas.P
T4 = driver_gas.T
a3 = [soundspeed_eq(driver_gas)]
u3 = [0]
elif CASE_DRIVER=='cj':
## Detonation driver with CJ wave moving away from diaphragm
EQ_EXP = True
P_driver_fill = P1; T_driver_fill = T1;
q4 = 'C2H2:1.0 O2:2.5'
driver_mech = 'gri30_highT.cti'
driver_gas = ct.Solution(driver_mech)
driver_gas.TPX = T_driver_fill,P_driver_fill,q4
rho4 = driver_gas.density
cj_speed = CJspeed(P_driver_fill, T_driver_fill, q4, driver_mech)
driver_gas = PostShock_eq(cj_speed,P_driver_fill, T_driver_fill, q4, driver_mech)
P4 = driver_gas.P
T4 = driver_gas.T
a3 = [soundspeed_eq(driver_gas)]
w3 = cj_speed*rho4/driver_gas.density
u3 = [w3-cj_speed]
## Evaluate initial state for expansion computation
rho3 = [driver_gas.density]
P3 = [driver_gas.P]
T3 = [driver_gas.T]
S4 = driver_gas.entropy_mass
## compute unsteady expansion (frozen)
print('Generating points on isentrope P-u curve')
gas.equilibrate('HP')
hp_rho.append(gas.density)
hp_exp.append(init_rho/hp_rho[-1])
hp_T.append(gas.T)
hp_ae.append(soundspeed_eq(gas))
# Constant Volume Explosion State
gas.TPX = T1,P1,x
gas.equilibrate('UV')
uv_P.append(gas.P)
uv_T.append(gas.T)
uv_ae.append(soundspeed_eq(gas))
# CJ speed
gas.TPX = T1,P1,x
Ucj.append(CJspeed(P1, T1, x, mech))
# vN state
gas1 = PostShock_fr(Ucj[-1], P1, T1, x, mech)
vn_T.append(gas1.T)
vn_P.append(gas1.P)
vn_rho.append(gas1.density)
vn_af.append(soundspeed_fr(gas1))
# ZND Structure
ZNDout = zndsolve(gas1,gas,Ucj[-1],advanced_output=True)
ind_len_ZND.append(ZNDout['ind_len_ZND'])
exo_len_ZND.append(ZNDout['exo_len_ZND'])
# CJ state
gas1 = PostShock_eq(Ucj[-1],P1, T1,x,mech)
from sdtoolbox.postshock import CJspeed
from sdtoolbox.postshock import PostShock_eq
import matplotlib.pyplot as plt
P1 = 100000
mech = 'gri30.cti'
gas = ct.Solution(mech)
for phi in range(50, 175, 25):
T1 = []
X = 'O2:2, N2:7.52, CH4:' + str(phi / 100)
cjspeed = []
for T in range(250, 2500, 250):
gas.TPX = T, P1, X
T1.append(T)
U = CJspeed(P1, T, X, mech)
cjspeed.append(U)
plt.plot(T1, cjspeed, label="phi=%.2f" % (phi / 100))
plt.legend()
plt.xlabel('Initial temperature [Kelvins]')
plt.ylabel('CJ speed [m/s]')
plt.title('Cj detonation speed of methane-air mixture', fontweight='bold')
plt.grid()
plt.savefig('methane_cjspeed(T1).png', dpi=1000)
plt.show()
for phi in range(50, 175, 25):
T1 = []
X = 'O2:2, N2:7.52, CH4:' + str(phi / 100)
PostShock_T = []
N2_comp = (1 - HC_comp) * 0.79
q = {'C3H8': HC_comp, 'O2': O_comp, 'N2': N2_comp}
mech = 'gri30.cti'
print('\nCJ computation for ' + mech + ' with composition:')
print(q)
print('Initial conditions: P1 = %.3e atm & T1 = %.2f K' %
(initpress, inittemp))
# generate gas solution and set initial conditions
preshockgas = ct.Solution(mech)
preshockgas.TPX = inittemp, initpress * ct.one_atm, q
# calculate CJ speed for gas mixture
cj_speed = CJspeed(initpress * ct.one_atm,
inittemp,
q,
mech,
fullOutput=False)
# calculate postshock gas condition
postshockgas = PostShock_fr(cj_speed, initpress * ct.one_atm, inittemp, q,
mech)
# save and print initial shock temp and pressure
shockedpress = postshockgas.P / 101325
shockedtemp = postshockgas.T
print(f' PostShock Pressure: {postshockgas.P/101325} atm')
print(f' PostShock Temperature: {postshockgas.T} K')
# Resolution: The PFR will be simulated by 'n_steps' time steps
n_steps = 3000000
ind_len_ZND = np.zeros(npoints,float)
Tf_ZND = np.zeros(npoints,float)
theta_effective_ZND = np.zeros(npoints,float)
# find Hydrogen nitrogen, and oxygen indices
ih2 = gas.species_index('H2')
io2 = gas.species_index('O2')
in2 = gas.species_index('N2')
x = 'H2:2.0,O2:1.0,N2:3.76'
T1 = 300
P1 = ct.one_atm; P1atm = P1/ct.one_atm
print('Initial Conditions')
print(x + ', Pressure = %.2f atm, Temperature = %.2f K' % (P1atm,T1))
print('For %s values of overdrive' % (npoints))
cj_speed = CJspeed(P1, T1, x, mech)
for i in range(npoints):
overdrive[i] = (1.0 +0.6/npoints*(i)) #Overdrive = U/Ucj
ratio = overdrive[i]
print('%i : Overdrive = %.2f ' % (i+1,ratio))
# Find post shock state for given speed
gas.TPX = T1,P1,x
gas = PostShock_fr(cj_speed*overdrive[i], P1, T1, x, mech)
Ts[i] = gas.T # frozen shock temperature
Ps[i] = gas.P # frozen shock pressure
### Constant Volume Explosion Data ###
# Solve constant volume explosion ODEs
R1 = ct.gas_constant/w1
gamma1_fr = a1_fr**2*rho1/P1
print('Layer detonation computation for '+mech+' with composition '+q)
print('State 1 - Initial state of reacting layer')
print(' Pressure '+str(P1)+' (Pa)')
print(' Temperature '+str(T1)+' (K)')
print(' Density '+str(rho1)+' (kg/m3)')
print(' Sound speed (frozen) '+str(a1_fr)+' (m/s)')
print(' Enthalpy '+str(h1)+' (J/kg)')
print(' Entropy '+str(s1)+' (J/kg K)')
print(' gamma (frozen) '+str(gamma1_fr)+' ')
##
# Find CJ speed
U_CJ = CJspeed(P1, T1, q, mech)
# Evaluate CJ gas state
gas = PostShock_eq(U_CJ,P1, T1, q, mech)
x2 = gas.X
P2 = gas.P
T2 = gas.T
rho2 = gas.density
a2_eq = soundspeed_eq(gas)
s2 = gas.entropy_mass
h2 = gas.enthalpy_mass
w2 = rho1*U_CJ/rho2
u2 = U_CJ-w2
gamma2_eq = a2_eq**2*rho2/P2
print('State 2 - CJ ')
print(' CJ speed '+str(U_CJ)+' (m/s)')
mech = 'gri30.xml'
#substance + oxygen
gas_initial2 = ct.Solution(mech)
gas_initial2.TPX = T0, P0, q1
# compute CJ speed for different prssures
speed2 = np.zeros(npoints)
P = np.linspace(0.1*ct.one_atm, ct.one_atm*3, npoints)
for i in range(npoints):
[cj_speed,R2,plot_data] = CJspeed(P[i], T0, q1, mech, fullOutput=True)
speed2[i] = cj_speed
print('V(p) for H2-oxygen mixture')
fig, ax = plt.subplots()
ax.plot(P/100000, speed2)
ax.set(xlabel='Pressure [bar]', ylabel='Detonation speed [m/s]')
ax.get_yaxis().get_major_formatter().set_useOffset(False)
plt.show()
# compute CJ speed fo different temperatures
speed5 = np.zeros(npoints)
T = np.zeros(T_steps)
cj_speed = np.zeros((p_steps, T_steps))
T_index = 0
p_index = 0
while p_index < p_steps:
P[p_index] = P1 + p_index * (Pmax - P1) / (p_steps - 1)
pbar[p_index] = P[p_index] / 100000
while T_index < T_steps:
T[T_index] = T1 + T_index * (Tmax - T1) / (T_steps - 1)
cj_speed[p_index, T_index] = CJspeed(P[p_index], T[T_index], q, mech)
T_index += 1
p_index += 1
T_index = 0
print('CJ computation for ' + mech + ' with composition ' + q)
print('CJ speed ' + str(np.round(cj_speed, 1)) + ' (m/s)')
font = {'family': 'DejaVu Sans', 'weight': 'normal', 'size': 18}
plt.rc('font', **font)
plt.figure(figsize=(20, 10))
for i in range(T_steps // 2):
plt.plot(pbar, cj_speed[:, 2 * i], label='T = %.0f K' % T[2 * i])
Windows 8.1, Windows 10, Linux (Debian 9)
"""
from sdtoolbox.postshock import CJspeed, PostShock_fr
from sdtoolbox.znd import zndsolve
from sdtoolbox.utilities import CJspeed_plot, znd_plot, znd_fileout
import cantera as ct
P1 = 100000
T1 = 300
q = 'H2:2 O2:1 N2:3.76'
mech = 'Mevel2017.cti'
file_name = 'h2air'
# Find CJ speed and related data, make CJ diagnostic plots
cj_speed, R2, plot_data = CJspeed(P1, T1, q, mech, fullOutput=True)
CJspeed_plot(plot_data, cj_speed)
# Set up gas object
gas1 = ct.Solution(mech)
gas1.TPX = T1, P1, q
# Find post shock state for given speed
gas = PostShock_fr(cj_speed, P1, T1, q, mech)
# Solve ZND ODEs, make ZND plots
znd_out = zndsolve(gas, gas1, cj_speed, t_end=1e-5, advanced_output=True)
znd_plot(znd_out)
znd_fileout(file_name, znd_out)
print('Reaction zone pulse width (exothermic length) = %.4g m' %
start = rho0; stop = 4*rho0; step = 0.5*rho0
nsteps = int((stop-start)/step)
for rho1 in np.linspace(start,stop,num=nsteps):
gas1.SVX = s0,1/rho1,x0
P1 = gas1.P
T1 = gas1.T
print('Density '+str(rho1)+' (kg/m^3)')
fid.write('# Initial conditions\n')
fid.write('# Temperature (K) %4.1f\n' % T1)
fid.write('# Pressure (Pa) %2.1f\n' % P1)
fid.write('# Density (kg/m^3) %1.4e\n' % rho1)
# Find CJ speed
cj_speed = CJspeed(P1, T1, q, mech)
print('CJspeed '+str(cj_speed)+' (m/s)');
gas = PostShock_eq(cj_speed,P1, T1, q, mech)
P2 = gas.P
# Evaluate overdriven detonations and reflected shocks
fstart = 1.; fstop = 1.5; fstep = 0.05
fnsteps = int((fstop-fstart)/fstep)
speed = []; vs = []; ps = []; pr = []; vr = []
for f in np.linspace(fstart,fstop,num=fnsteps):
u_shock = f*cj_speed
speed.append(u_shock)
print(' Detonation Speed '+str(speed[-1])+' (m/s)')
gas = PostShock_eq(u_shock,P1, T1, q, mech)
# Evaluate properties of gas object
vs.append(1./gas.density)
print('Initial Conditions')
print(x + ', Temperature = %.2f K' % (T1))
print('For %s initial pressures' % (npoints))
for i in range(npoints):
P1[i] = Po*(0.1 +1.1/npoints*(i))
P = P1[i]
print('%i : P1 = %.2f atm' % (i+1,P/ct.one_atm))
gas.TPX = T1,P1[i],x
### Constant Volume Explosion Data ###
# FIND POST SHOCK STATE FOR GIVEN SPEED
cj_speed[i] = CJspeed(P1[i], T1, x, mech)
gas = PostShock_fr(cj_speed[i], P1[i], T1, x, mech)
Ts[i] = gas.T #frozen shock temperature
Ps[i] = gas.P #frozen shock pressure
# SOLVE CONSTANT VOLUME EXPLOSION ODES
CVout = cvsolve(gas,t_end=1e-4)
exo_time_CV[i] = CVout['exo_time']
ind_time_CV[i] = CVout['ind_time']
### ZND Detonation Data ###
# FIND POST SHOCK STATE FOR GIVEN SPEED
gas1.TPX = T1,P1[i],x
gas = PostShock_fr(cj_speed[i], P1[i], T1, x, mech)
Ts[i] = gas.T #frozen shock temperature
Ps[i] = gas.P #frozen shock pressure