An Evaluation of Rotated-RoeM Flux Scheme for Hypersonic Equilibrium Flow Computation

초록

This paper explores the ongoing development of the rotated-RoeM flux scheme, which has demonstrated considerable success in efficiently resolving strong shock waves using compact stencils for an ideal gas. The primary focus lies in extending this scheme to solve hypersonic equilibrium flow. Our approach involves employing the rotated hybrid concept within the flux scheme to suppress spurious oscillations along grid-aligned shock waves. Furthermore, a Mach-number-based weighting function is introduced to discern between boundary layer flow and the onset of shock instability. The efficacy of the proposed scheme is evident in its ability to handle compressible viscous flow for calorically perfect gases. Notably, it avoids shock anomalies, such as the Carbuncle phenomena, and accurately estimates the heat transfer rate over blunt bodies. Hypersonic vehicles navigating atmospheric re-entry encounter air undergoing chemical reactions due to extensive aerodynamic heating. In an equilibrium state, thermodynamic and transport properties become interdependent functions of other properties, such as density and temperature. IDEA library, a collection of artificial neural network models for air properties, was used to compute equilibrium states efficiently. Incorporating the equilibrium air model with the rotated-RoeM scheme enables the computation of hypersonic equilibrium flow. Extensive numerical analyses underscore the effectiveness of our proposed flux scheme in resolving multi-dimensional strong shock waves and thermal boundary layers to predict heat transfer rates around stagnation points in hypersonic equilibrium flow.

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