Studies on Fluid-Thermal-Structural Coupling for Aerothermoelasticity in Hypersonic Flow

TLDR

The field of aerothermoelasticity plays an important role in the analysis and optimization of airbreathing hypersonic vehicles, impacting the design of the aerodynamic, structural, control, and propulsion systems at both the component and multi-disciplinary levels. This study aims to expand the fundamental understanding of hypersonic aerothermoelasticity by performing systematic investigations into fluid‑thermal‑structural coupling and developing innovative modeling frameworks to reduce the computational effort associated with aerothermoelastic analysis. The analysis focuses on cylindrical bending of a simply‑supported von Kármán panel, incorporating arbitrary nonuniform temperature distributions, temperature‑dependent material property degradation, and the influence of elastic deformation on aerodynamic heating, while evaluating trade‑offs between computational cost and accuracy across quasi‑static, time‑averaged dynamic coupling, and reduced‑order CFD‑based heat‑flux modeling. Including elastic deformations in aerodynamic heating calculations produces nonuniform heat flux, leading to uneven temperature distributions and material property degradations that shorten flight time to flutter onset and create localized regions where material temperature limits are exceeded, and the evaluated modeling approaches show potential for significant efficiency and/or accuracy improvements.

Abstract

The field of aerothermoelasticity plays an important role in the analysis and optimization of airbreathing hypersonic vehicles, impacting the design of the aerodynamic, structural, control, and propulsion systems at both the component and multi-disciplinary levels. This study aims to expand the fundamental understanding of hypersonic aerothermoelasticity by performing systematic investigations into fluid-thermal-structural coupling, and also to develop frameworks, using innovative modeling strategies, for reducing the computational effort associated with aerothermoelastic analysis. Due to the fundamental nature of this work, the analysis is limited to cylindrical bending of a simply-supported, von K arm an panel. Multiple important effects are included in the analysis, namely: 1) arbitrary, nonuniform, in-plane and through-thickness temperature distributions, 2) material property degradation at elevated temperature, and 3) the effect of elastic deformation on aerodynamic heating. It is found that including elastic deformations in the aerodynamic heating computations results in non-uniform heat flux, which produces non-uniform temperature distributions and non-uniform material property degradations. This results in reduced flight time to the onset of flutter and localized regions in which the material temperature limits may be exceeded. Additionally, the trade-off between computational cost and accuracy is evaluated for aerothermoelastic analysis based on either quasi-static or time-averaged dynamic fluid-thermal-structural coupling, as well as computational fluid dynamics based reduced-order modeling of the aerodynamic heat flux. It is determined that these approaches offer the potential for significant improvements in aerothermoelastic modeling in terms of efficiency and/or accuracy.