Progress towards understanding the physics of high-speed boundary layer instability
University of Delaware
Abstract
Over the last decade, significant advances in our understanding of hypersonic boundary layer stability have been made. Many of these advances have come via developments of new experimental capabilities, advances in both computing power and code development, and through flight testing. In this talk, improvements to our understanding based in theoretical advances will be emphasized as well as their relationship with the experimental and computational advances. The discussion will focus on: The recognition that vortex modes evolve along paths defined by the crossflow inflectional profile. The development of a wave packet formulation for the Nonlinear Parabolized Stability Equations method. A thermoacoustic interpretation of second mode instability. A clarification of the fundamental dynamics of first mode instability. Consequences of these advances will be discussed in relationship to multi-mode/mechanism instability physics and nose bluntness effects.
About the speaker
Dr. Joseph Kuehl is an Associate Professor at the University of Delaware in the Mechanical Engineering Department. He holds Ph.D.s in Physical Oceanography and Mechanical Engineering from the Graduate School of Oceanography and Department of Mechanical, Industrial, and Systems Engineering at the University of Rhode Island (2009). His research interests include geophysical fluid dynamics (gap-leaping boundary currents, geophysical boundary layer dynamics and transport phenomena), hypersonic boundary-layer stability (numerical laminar-turbulent transition) and nonlinear vibrations (time series analysis, modal decomposition techniques and finite time invariant manifold analysis). He was the recipient of the AFOSR Young Investigator Award (2015) for his hypersonic boundary layer stability and transition research, participates in the NATO STO AVT hypersonic vehicle working groups (240, 190, 346) and was a member of the National Academy of Science Committee on Advancing Understanding of the Gulf of Mexico Loop Current Dynamics.
