Towards More Physics-based Transition Prediction by Incorporating Receptivity for Hypersonic Boundary Layers

Abstract

Accurate prediction of the boundary layer transition is highly desirable in the design of hypersonic flight vehicles. Traditional method predicts the transition location based on the most amplified linear instability mode but neglects receptivity that initiates the instability. In this seminar, Prof. Su will report on their research endeavors aimed at elucidating the receptivity process and improving the transition prediction method. Specifically, they focus on the receptivity of a blunt cone boundary layer to freestream disturbances, using direct numerical simulation and linear stability theory. They have developed a novel method for identifying the key disturbances exciting the first and second modes. This method has revealed a notable consistency in the receptivity mechanisms across a wide range of nose bluntness. Building upon this insight, they established a receptivity model and incorporated it into the transition prediction method. The improved approach indicated that the first mode, which is often overlooked in transitional predictions, may contribute to transition due to its significantly effective receptivity process.

Speaker

Prof. Caihong Su is a Professor in the Laboratory of High-Speed Aerodynamics at Tianjin University. She earned her Bachelor’s degree in Engineering Mechanics in 2003 and her PhD in Fluid Mechanics in 2008, both from Tianjin University. After completing her PhD, she joined the faculty at Tianjin University, where she was promoted to the rank of Professor in 2018. Currently, she serves as a Committee Member of the Fluid Mechanics Specialty in the Chinese Society of Theoretical and Applied Mechanics and as the Deputy Head of the Turbulence and Stability Special Group.