Multi-scale porous media modeling for liquid rocket injector applications

Porous materials are often used for the injector face plate of liquid propellant rocket engines (LPRE). To develop predictive capabilities for such porous media fuel flow problems, a multi-scale modeling strategy is developed. The effect of porous structure on the macroscopic fluid flow is accounted for via local volume averaged governing equations. The resulting set of transport equations, at the global domain level, contains closure terms representing the statistical flow characteristics around the pores. Conventionally, the closure terms are evaluated using empirical correlations. In the present approach, these closure terms in the global fluid flow equations are deduced via direct computation of the fluid flow in individual, representative pores. Hence, empirical dependence of simulations can be removed without requiring excessive computational cost. The performance of the present approach is demonstrated by studying isothermal fluid flow through a porous plate with an array of uniformly drilled holes. As a preliminary step towards multi-scale closure of the energy equation, a global scale heat transfer analysis case is also conducted to illustrate the scope of the entire theoretical framework.