Wall-modeled large eddy simulation of high-speed high-enthalpy turbulent boundary layers with catalytic effects

The catalytic effects intensify near-wall chemical reactions in high-enthalpy turbulent boundary layers and strongly influence the heat fluxes, posing significant difficulties for the wall-modeled large eddy simulation. To tackle these issues, this study proposes a multi-species ordinary differential equation (ODE) based wall model to describe the near-wall catalytic effects. A computationally robust and efficient framework is established based on the pseudo-time implicit iteration in conjunction with reaction-flow splitting. To incorporate turbulence–chemistry interactions (TCIs), the assumed probability-density-function method is considered by solving an ODE-based transport equation of temperature variance, thereby enhancing the prediction accuracy of near-wall species mass fractions. The model's performance is evaluated through systematic a priori and a posteriori validation. A priori tests confirm that TCI effects must be accounted for in high-enthalpy catalytic wall flows. A posteriori results demonstrate that the proposed model accurately captures the characteristics of high-enthalpy turbulent boundary layers with catalytic walls. Importantly, the errors in predicted skin friction and wall heat flux are less than 10%, meeting practical engineering requirements while balancing accuracy and computational cost.