Recent Insights into Stability and Transition of High-Speed Flows

Abstract

In the past several decades, remarkable accomplishments have been achieved by China in space exploration programs. During these missions, the high-speed vehicles are crucial to travel across the atmosphere. As the vehicle is accelerated to several times the sound speed, the escalated drag force and severe aerodynamic heating arising from boundary layer transition are highly challenging. Currently, the instability and transition to turbulence of high-speed flows are far from being well understood. In this seminar, some recent insights into the above topic will be provided. First, a unified framework to comprehend the linear instability stage will be discussed. Second, the nonlinear mode-mode interaction, a newly identified breakdown scenario and the heat transfer overshoot will be revisited. Finally, new understandings of the linear instability of the shock wave/boundary layer interaction will be introduced.

Speaker

Dr Peixu Guo obtained BEng and PhD degrees from Beihang University in China in 2016 and 2022 respectively, and was the recipient of National Scholarship and Outstanding Graduates Award. Dr Guo joined Department of Aeronautical and Aviation Engineering, The Hong Kong Polytechnic University as Postdoctoral Fellow in 2022, with research interests in stability and laminar-turbulent transition of high-speed flows. Dr Guo has devoted to theoretical and computational studies on linear instability and nonlinear breakdown mechanisms of wall-bounded flows. He has also made contributions to the transition control, transition modelling and adjoint-based sensitivity analysis of hypersonic flows, with publications in J. Fluid Mech., Phys. Fluids, and AIAA J., etc. He also serves as Co-PI for a project with the Academy of Aerospace Propulsion Technology; as Co-I for a GRF project; as co-supervisor of PhD students; and as reviewer for J. Fluid Mech..