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cantera/samples/python/reactors/piston.py
2024-12-02 10:06:01 -05:00

98 lines
2.9 KiB
Python

"""
Reactors separated by a moving piston
=====================================
Two reactors separated by a piston that moves with a speed proportional to the pressure
difference between the reactors.
- Gas 1: a stoichiometric H2/O2/Ar mixture
- Gas 2: a wet CO/O2 mixture
.. code:: none
-------------------------------------
| || |
| || |
| gas 1 || gas 2 |
| || |
| || |
-------------------------------------
The two volumes are connected by an adiabatic free piston. The piston speed is
proportional to the pressure difference between the two chambers.
Note that each side uses a *different* reaction mechanism
Requires: cantera >= 2.5.0, matplotlib >= 2.0
.. tags:: Python, combustion, reactor network, plotting
"""
import sys
import cantera as ct
import matplotlib.pyplot as plt
plt.rcParams['figure.constrained_layout.use'] = True
# %%
# Create objects representing the gases and reactors
gas1 = ct.Solution('h2o2.yaml')
gas1.TPX = 900.0, ct.one_atm, 'H2:2, O2:1, AR:20'
gas2 = ct.Solution('gri30.yaml')
gas2.TPX = 900.0, ct.one_atm, 'CO:2, H2O:0.01, O2:5'
r1 = ct.IdealGasReactor(gas1)
r1.volume = 0.5
r2 = ct.IdealGasReactor(gas2)
r2.volume = 0.1
# %%
# The wall is held fixed until t = 0.1 s, then released to allow the pressure to
# equilibrate.
def v(t):
if t < 0.1:
return 0.0
else:
return (r1.thermo.P - r2.thermo.P) * 1e-4
w = ct.Wall(r1, r2, velocity=v)
net = ct.ReactorNet([r1, r2])
# %%
# Run the simulation and collect the states of each reactor
states1 = ct.SolutionArray(r1.thermo, extra=['t', 'volume'])
states2 = ct.SolutionArray(r2.thermo, extra=['t', 'volume'])
fmt = '{:10.3f} {:10.1f} {:10.4f} {:10.4g} {:10.4g} {:10.4g} {:10.4g}'
print('{:>10} {:>10} {:>10} {:>10} {:>10} {:>10} {:>10}'.format(
'time [s]', 'T1 [K]', 'T2 [K]', 'V1 [m^3]', 'V2 [m^3]', 'Vtot [m^3]', 'X(CO)'))
for n in range(200):
time = (n+1)*0.001
net.advance(time)
if n % 4 == 3:
print(fmt.format(time, r1.T, r2.T, r1.volume, r2.volume,
r1.volume + r2.volume, r2.thermo['CO'].X[0]))
states1.append(r1.thermo.state, t=1000*time, volume=r1.volume)
states2.append(r2.thermo.state, t=1000*time, volume=r2.volume)
# %%
# Plot the results
fig, ax = plt.subplots(2, 2)
ax[0,0].plot(states1.t, states1.T, '-', states2.t, states2.T, 'r-')
ax[0,0].set(xlabel='Time (ms)', ylabel='Temperature (K)')
ax[0,1].plot(states1.t, states1.volume, '-', states2.t, states2.volume, 'r-',
states1.t, states1.volume + states2.volume, 'g-')
ax[0,1].set(xlabel='Time (ms)', ylabel='Volume (m3)')
ax[1,0].plot(states2.t, states2('CO').X)
ax[1,0].set(xlabel='Time (ms)', ylabel='CO Mole Fraction (right)')
ax[1,1].plot(states1.t, states1('H2').X)
ax[1,1].set(xlabel='Time (ms)', ylabel='H2 Mole Fraction (left)')
plt.show()