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.
117 lines
3.9 KiB
Python
117 lines
3.9 KiB
Python
#
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# STFLAME1 - A detached flat flame stabilized at a stagnation point
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#
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# This script simulates a lean hydrogen-oxygen flame stabilized in
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# a strained flowfield at an axisymmetric stagnation point on a
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# non-reacting surface. The solution begins with a flame attached
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# to the inlet (burner), and the mass flow rate is progressively
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# increased, causing the flame to detach and move closer to the
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# surface. This example illustrates use of the new 'prune' grid
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# refinement parameter, which allows grid points to be removed if
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# they are no longer required to resolve the solution. This is
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# important here, since the flamefront moves as the mass flowrate
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# is increased. Without using 'prune', a large number of grid
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# points would be concentrated upsteam of the flame, where the
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# flamefront had been previously. (To see this, try setting prune
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# to zero.)
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from Cantera import *
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from Cantera.OneD import *
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from Cantera.OneD.StagnationFlow import StagnationFlow
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################################################################
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#
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# parameter values
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#
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p = 0.05*OneAtm # pressure
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tburner = 373.0 # burner temperature
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tsurf = 600.0
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# each mdot value will be solved to convergence, with grid refinement,
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# and then that solution will be used for the next mdot
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mdot = [0.06, 0.07, 0.08, 0.09, 0.1, 0.11, 0.12] # kg/m^2/s
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rxnmech = 'h2o2.cti' # reaction mechanism file
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comp = 'H2:1.8, O2:1, AR:7' # premixed gas composition
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# The solution domain is chosen to be 50 cm, and a point very near the
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# downstream boundary is added to help with the zero-gradient boundary
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# condition at this boundary.
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initial_grid = [0.0, 0.02, 0.04, 0.06, 0.08, 0.1,
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0.15, 0.2] # m
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tol_ss = [1.0e-5, 1.0e-13] # [rtol atol] for steady-state
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# problem
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tol_ts = [1.0e-4, 1.0e-9] # [rtol atol] for time stepping
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loglevel = 1 # amount of diagnostic output (0
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# to 5)
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refine_grid = 1 # 1 to enable refinement, 0 to
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# disable
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ratio = 5.0
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slope = 0.1
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curve = 0.2
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prune = 0.05
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################ create the gas object ########################
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#
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# This object will be used to evaluate all thermodynamic, kinetic,
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# and transport properties
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#
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gas = IdealGasMix(rxnmech)
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# set its state to that of the unburned gas at the burner
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gas.setState_TPX(tburner, p, comp)
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# Create the stagnation flow object with a non-reactive surface. (To
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# make the surface reactive, supply a surface reaction mechanism. see
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# example catcomb.py for how to do this.)
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f = StagnationFlow(gas = gas, grid = initial_grid)
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# set the properties at the inlet
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f.inlet.set(massflux = mdot[0], mole_fractions = comp, temperature = tburner)
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# set the surface state
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f.surface.setTemperature(tsurf)
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f.set(tol = tol_ss, tol_time = tol_ts)
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f.setMaxJacAge(5, 10)
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f.set(energy = 'off')
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f.init(products = 'equil') # assume adiabatic equilibrium products
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f.showSolution()
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f.solve(loglevel, refine_grid)
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f.setRefineCriteria(ratio = ratio, slope = slope,
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curve = curve, prune = prune)
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f.set(energy = 'on')
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m = 0
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for md in mdot:
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f.inlet.set(mdot = md)
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f.solve(loglevel,refine_grid)
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m = m + 1
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f.save('stflame1.xml','mdot'+`m`,'mdot = '+`md`+' kg/m2/s')
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# write the velocity, temperature, and mole fractions to a CSV file
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z = f.flow.grid()
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T = f.T()
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u = f.u()
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V = f.V()
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fcsv = open('stflame1_'+`m`+'.csv','w')
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writeCSV(fcsv, ['z (m)', 'u (m/s)', 'V (1/s)', 'T (K)']
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+ list(gas.speciesNames()))
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for n in range(f.flow.nPoints()):
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f.setGasState(n)
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writeCSV(fcsv, [z[n], u[n], V[n], T[n]]+list(gas.moleFractions()))
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fcsv.close()
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print 'solution saved to flame1.csv'
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f.showStats()
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