Prediction of aerothermal characteristics of a generic hypersonic inlet flow

TL;DR

This paper demonstrates that wall-modeled large-eddy simulation (WMLES) can accurately predict aerothermal characteristics of hypersonic inlets at Mach 8.3, outperforming RANS models, with implications for high-speed vehicle design.

Contribution

It introduces a WMLES approach with semi-local eddy viscosity scaling for hypersonic inlet flow prediction, showing improved accuracy over traditional RANS methods.

Findings

WMLES accurately predicts surface heat flux and pressure distributions.

Semi-local eddy viscosity scaling improves prediction accuracy.

WMLES outperforms prior RANS calculations in complex hypersonic flow.

Abstract

The accurate prediction of aerothermal surface loading is of paramount importance for the design of high speed flight vehicles. In this work, we consider the numerical solution of hypersonic flow over a double-finned geometry, representative of the inlet of an air-breathing flight vehicle, characterized by three-dimensional intersecting shock-wave/turbulent boundary-layer interaction at Mach 8.3. High Reynolds numbers ($Re_L \approx 11.6 \times 10^6$ based on free-stream conditions) and the presence of cold walls ($T_w/T_o \approx 0.27$) leading to large near-wall temperature gradients necessitate the use of wall-modeled large-eddy simulation (WMLES) in order to make calculations computationally tractable. The comparison of the WMLES results with experimental measurements shows good agreement in the time-averaged surface heat flux and wall pressure distributions, and the WMLES predictions show reduced errors with respect to the experimental measurements than prior RANS calculations. The favorable comparisons are obtained using an LES wall model based on equilibrium boundary layer approximations despite the presence of numerous non-equilibrium conditions including three dimensionality, shock-boundary layer interactions, and flow separation. Lastly, it is also demonstrated that the use of semi-local eddy viscosity scaling (in lieu of the commonly used van Driest scaling) in the LES wall model is necessary to accurately predict the surface pressure loading and heat fluxes.