2528df0f75
These changes make it unnecessary to copy header files around during the build process, which tends to confuse IDEs and debuggers. The headers which comprise Cantera's external C++ interface are now in the 'include' directory. All of the samples and demos are now in the 'samples' subdirectory.
103 lines
3.8 KiB
Python
103 lines
3.8 KiB
Python
# Mixing two streams.
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# Since reactors can have multiple inlets and outlets, they can be
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# used to implement mixers, splitters, etc. In this example, air and
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# methane are mixed in stoichiometric proportions. Due to the low
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# temperature, no reactions occur. Note that the air stream and the
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# methane stream use *different* reaction mechanisms, with different
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# numbers of species and reactions. When gas flows from one reactor or
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# reservoir to another one with a different reaction mechanism,
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# species are matched by name. If the upstream reactor contains a
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# species that is not present in the downstream reaction mechanism, it
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# will be ignored. In general, reaction mechanisms for downstream
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# reactors should contain all species that might be present in any
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# upstream reactor.
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#
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#-----------------------------------------------------------------------
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from Cantera import *
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from Cantera.Reactor import *
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# Use air for stream a. Note that the Air() function does not set the
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# composition correctly; thus, we need to explicitly set the
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# composition to that of air.
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gas_a = Air()
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gas_a.set(T = 300.0, P = OneAtm, X = 'O2:0.21, N2:0.78, AR:0.01')
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rho_a = gas_a.density()
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# Use GRI-Mech 3.0 for stream b (methane) and for the mixer. If it is
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# desired to have a pure mixer, with no chemistry, use instead a
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# reaction mechanism for gas_b that has no reactions.
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gas_b = GRI30()
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gas_b.set(T = 300.0, P = OneAtm, X = 'CH4:1')
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rho_b = gas_b.density()
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# Create reservoirs for the two inlet streams and for the outlet
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# stream. The upsteam reservoirs could be replaced by reactors, which
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# might themselves be connected to reactors further upstream. The
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# outlet reservoir could be replaced with a reactor with no outlet, if
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# it is desired to integrate the composition leaving the mixer in
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# time, or by an arbitrary network of downstream reactors.
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res_a = Reservoir(gas_a)
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res_b = Reservoir(gas_b)
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downstream = Reservoir(gas_b)
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# Create a reactor for the mixer. A reactor is required instead of a
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# reservoir, since the state will change with time if the inlet mass
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# flow rates change or if there is chemistry occurring.
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mixer = Reactor(gas_b)
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# create two mass flow controllers connecting the upstream reservoirs
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# to the mixer, and set their mass flow rates to values corresponding
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# to stoichiometric combustion.
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mfc1 = MassFlowController(upstream = res_a,
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downstream = mixer,
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mdot = rho_a*2.5/0.21)
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mfc2 = MassFlowController(upstream = res_b,
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downstream = mixer,
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mdot = rho_b*1.0)
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# add an igniter to ignite the mixture. The 'igniter' consists of a
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# stream of pure H.
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gas_c = IdealGasMix('h2o2.cti')
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gas_c.set(T = 300.0, P = OneAtm, X = 'H:1')
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igniter = Reactor(gas_c)
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mfc3 = MassFlowController(upstream = igniter, downstream = mixer,
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mdot = 0.05)
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# connect the mixer to the downstream reservoir with a valve.
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outlet = Valve(upstream = mixer, downstream = downstream, Kv = 1.0)
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sim = ReactorNet([mixer])
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# Since the mixer is a reactor, we need to integrate in time to reach
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# steady state. A few residence times should be enough.
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t = 0.0
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for n in range(30):
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tres = mixer.mass()/(mfc1.massFlowRate() + mfc2.massFlowRate())
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t += 0.5*tres
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sim.advance(t)
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# if ignited, turn the igniter off.
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# We also need to restart the integration in this case.
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if mixer.temperature() > 1200.0:
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mfc3.set(mdot = 0.0)
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sim.setInitialTime(t)
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print '%14.5g %14.5g %14.5g %14.5g %14.5g' % (t, mixer.temperature(),
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mixer.enthalpy_mass(),
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mixer.pressure(),
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mixer.massFraction('CH4'))
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# view the state of the gas in the mixer
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print mixer.contents()
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