Transition from laminar to turbulent flow in high-speed boundary layers remains a fundamental challenge in fluid dynamics. This challenge arises in part from the inherently nonlinear nature of transition, where small changes in vehicle geometry or flow conditions can lead to significantly different outcomes. Accurately simulating laminar-turbulent transition is essential for predicting aerodynamic heating, drag, and structural loads in high-speed flight, all of which have a major impact on vehicle performance and design. While transition research often focuses on its onset and breakdown to turbulence, the significance of the transitional regime itself is sometimes underestimated. Yet, it can extend over large portions of high-speed vehicles and, in some cases, lead to greater localized heating compared to fully developed turbulent flow.
Christoph Hader,
University of Arizona
This talk explores how numerical simulations help us understand the fundamental physics of high-speed boundary-layer transition. Because transition is highly sensitive to flow conditions and geometry, simulations allow us to systematically examine how specific parameters influence its development. While transition simulations have been instrumental in revealing important physical processes, accurately capturing transition in large-scale computations continues to be challenging. How much do our simulations get right, and where could we still do better?
Along the way, I’ll share key findings from transition simulations at the University of Arizona, discuss open questions in transition research and how simulations can help address them, and briefly consider where high-fidelity simulations might take us next.
Christoph Hader is an assistant professor in the Department of Aerospace and Mechanical Engineering at the University of Arizona. He earned his M.S. and Ph.D. at the University of Arizona, both focused on high-speed transition simulations. During his Ph.D., he spent a year at NASA Ames Research Center, working with the NASA Advanced Supercomputing Division to support the development of a novel immersed boundary method. His research focuses on high-fidelity direct numerical simulations to investigate the underlying physical mechanisms of high-speed boundary-layer transition for both wind tunnel and flight conditions.