Continue generalizing flamelet equations
Spitfire Feature Request
Summary and Motivation
Recently we have generalized our flamelet equations by adding the variable heat capacity and consistent enthalpy flux (distinct species heat capacities) terms. This has been important in getting good results for both adiabatic and nonadiabatic flamelet libraries. Since deriving these additional terms I've generalized the derivation to include a variety of models for the mass diffusive fluxes.
Desired Behavior and Interface, and Development Estimate
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Support a use_molar_flux
entry in theFlamelet
constructor that uses mole fraction gradients to determine diffusive fluxes. The default will continue to be to compute fluxes from mass fractions. -
Support a use_Curtiss_Hirschfelder_approximation
entry to theFlamelet
constructor to compute allN
mass fluxes and correct them for mass conservation according to Curtiss and Hirschfelder's procedure. The default will be the current behavior of formingN-1
fluxes and using mass conservation to directly set theN
-th flux.
Note that these two parameters create four diffusive flux models.
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Support a consistent nonunity, constant Lewis number formulation. This involves simply making the existing Lewis number treatment consistent and being careful with respect to the four diffusion models supported. -
Support a nonconstant Lewis number formulation, with mixture-averaged transport properties. This is a big task that likely won't be done until there is a direct motivation. This is also part of Issue #44.