Numerical Investigation of Coupled Aerothermoelastic Effects on Hypersonic Intake Performance

This paper investigates fluid–thermal–structural interaction (FTSI) in a two‑dimensional smooth compression planar hypersonic intake using an open‑source partitioned framework that couples a compressible flow solver in OpenFOAM for the flow solution with CalculiX for the nonlinear structural and thermal response. Coupled simulations are performed for experimentally relevant cold flow conditions and for a hot flow condition representative of International Standard Atmosphere (ISA) 32 km, allowing assessment of aerothermoelastic effects on intake performance. For realistic material properties, the compliant intake exhibits modestly larger leading‑edge deflections and slightly reduced oscillation frequency in hot flow compared with cold flow, but in both cases, aerothermoelastic deformation increases the flow‑turning angle, strengthens compression shocks, and modifies shock‑wave–boundary‑layer interaction inside the isolator. These changes induce flow spillage and substantial restructuring of the internal flow, leading to peak reductions in mass‑averaged total pressure recovery (TPR) of up to 24% and 20% in cold and hot flow cases, respectively, and introducing significant hysteresis in the TPR response due to separation‑bubble dynamics. An additional parametric study with artificially reduced solid specific heat demonstrates that more extreme aerodynamic heating can drive the intake into a locally unstarted state, with TPR losses exceeding 60% and three distinct deformation regimes ranging from nearly linear response to strongly hysteretic behavior and local unstart. The results show that aerothermoelastic effects can fundamentally shift intake operability limits, highlighting the need to incorporate FTSI considerations in hypersonic intake structural and thermal design to constrain panel deformation and mitigate separation bubble growth.