72 lines
2.4 KiB
Matlab
72 lines
2.4 KiB
Matlab
% Tutorial 6: Transport properties
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%
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% Topics:
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% - mixture-averaged and multicomponent models
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% - viscosity
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% - thermal conductivity
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% - binary diffusion coefficients
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% - mixture-averaged diffusion coefficients
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% - multicomponent diffusion coefficients
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% - thermal diffusion coefficients
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%
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%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
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% Methods are provided to compute transport properties. By
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% default, calculation of transport properties is not enabled. If
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% transport properties are required, the transport model must be
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% specified when the gas mixture object is constructed.
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% Currently, two models are implemented. Both are based on kinetic
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% theory expressions, and follow the approach described in Dixon-Lewis
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% (1968) and Kee, Coltrin, and Glarborg (2003). The first is a full
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% multicomponent formulation, and the second is a simplification that
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% uses expressions derived for mixtures with a small number of species
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% (1 to 3), using approximate mixture rules to average over
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% composition.
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% To use the multicomponent model with GRI-Mech 3.0, call function
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% GRI30 as follows:
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g1 = GRI30('Multi')
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% To use the mixture-averaged model:
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g2 = GRI30('Mix')
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% Both models use a mixture-averaged formulation for the viscosity.
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visc = [viscosity(g1), viscosity(g2)]
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% The thermal conductivity differs, however.
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lambda = [thermalConductivity(g1), thermalConductivity(g2)]
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% Binary diffusion coefficients
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bdiff1 = binDiffCoeffs(g1)
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bdiff2 = binDiffCoeffs(g2)
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% Mixture-averaged diffusion coefficients. For convenience, the
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% multicomponent model implements mixture-averaged diffusion
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% coefficients too.
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dmix2 = mixDiffCoeffs(g1)
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dmix1 = mixDiffCoeffs(g2)
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% Multicomponent diffusion coefficients. These are only implemented
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% if the multicomponent model is used.
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dmulti = multiDiffCoeffs(g1)
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% Thermal diffusion coefficients. These are only implemented with the
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% multicomponent model. These will be very close to zero, since
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% the composition is pure H2.
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dt = thermalDiffCoeffs(g1)
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% Now change the composition and re-evaluate
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set(g1,'X',ones(nSpecies(g1),1));
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dt = thermalDiffCoeffs(g1)
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% Note that there are no singularities for pure gases. This is
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% because a very small positive value is added to all mole
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% fractions for the purpose of computing transport properties.
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%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
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clear all
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cleanup
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