AEROSPACE ENGINEERING

Abstract

Boundary-layer transition from laminar to turbulent flow critically affects vehicle safety and performance, particularly at hypersonic speeds where heat-transfer rates are extreme. Accounting for these effects requires robust tools capable of modeling the underlying physical mechanisms that lead to turbulence. Current research aims to develop these tools in an effort to supplement and improve existing empirical correlations. This will allow vehicle designers to conduct a sufficiently accurate analysis on pace with a rapid design cycle. Developing models suitable for industry application requires a balance between efficiency and accuracy. Transition is notoriously sensitive to the details of the underlying flow; therefore, any reduced-order models must balance correct physical assumptions with rising computational costs. This challenge is apparent when modeling regions of rapidly varying flow on realistic vehicles. To demonstrate these principles, this talk focuses on a slender cone with a single, highly swept fin at Mach 6. The fin induces strong pressure gradients which give rise to multiple large, stationary vortices. The distinct physical mechanisms driving transition on the fin and cone are particularly challenging to model due to the complexity of the flow. Rather than simulating the entire problem at once, portions of the flow are modeled using a wide range of stability methods. These methods range in computation time from minutes on a local workstation to days on a supercomputer. This overview of the transition on the finned cone exemplifies how different stability models may be combined to break down the difficult task of predicting transition on realistic vehicles.

Speaker

Madeline Peck

Ph.D. candidate in Aerospace Engineering at Texas A&M University researching hypersonic boundary-layer transition using high fidelity computational fluid dynamics and linear stability theory. She received her bachelor's degree in 2018 and master's degree in 2019, both from Texas A&M in Aerospace Engineering. Her undergraduate and master's research included both experimental and computational efforts to understand how random, distributed roughness affects low-speed boundary layers. In 2021, Madeline was awarded the Amelia Earhart Fellowship through Zonta International.