In 3D aerodynamics, is it the forest or the trees?
Virginia Polytechnic Institute and State University (Virginia Tech)
Abstract
Three-dimensionality is the rule rather than the exception in air vehicle aerodynamics. In some cases, such as low Mach number boundary layer flow over high aspect ratio swept wings, the most important three-dimensional dynamics can often be explained by local effects. In other systems such as high-lift devices where the boundary layer may separate from the body, complex links among large-scale and local phenomena exist. In this talk, I will share the latest culmination of insights gained from the literature synthesized with new results being obtained from an on-going study of boundary layer separation over a three-dimensional hill. The contemporary study is termed Benchmark Validation Experiments for RANS/LES Investigations, or BeVERLI, while the associated geometry is termed the BeVERLI hill. This NASA-supported effort has the overarching goal of generating a new database of turbulence modeling benchmark data, but the test cases also present rich turbulent flow physics themselves worthy of deeper examination. Experimental results for the windward, attached boundary layer flows for the BeVERLI hill will be discussed regarding effects of boundary layer skewing, pressure gradient, and curvature. Additionally, mean flow symmetry breaking seen in both experiments and simulations will be discussed for a broad range of implications for flow physics, computational and experimental research approaches, and aerodynamic design.
For the last third of the talk, I will shift gears to provide a perspective on professional development, careers after graduate school, and share where some of the graduates from our team have gone in their careers.
About the speaker
Dr. Todd Lowe is a professor in the Kevin T. Crofton Department of Aerospace and Ocean Engineering at Virginia Tech. After receiving B.S., M.S., and Ph.D. degrees in aerospace engineering at Virginia Tech, he spent four years working in small business developing laser flow instrumentation, including work on a laser-Doppler velocimeter that would later be used in the NASA Juncture Flow Computational Fluid Dynamics Validation Experiment. In 2011, he rejoined Virginia Tech and now leads a research team focused on experimental aerodynamics and aeroacoustics, often addressing applications on propulsion inlets and exhausts. His fundamental contributions have provided insights for understanding turbulence transport and noise in turbulent shear flows, while parallel experimental technology research has advanced the state-of-the-art in nonintrusive flow diagnostics. He is co-inventor of four US utility patents, with four additional patents pending, and has co-authored more than 150 publications in the areas of advanced instrumentation, turbulent shear flow, supersonic jet noise, and turbulence modeling benchmark experiments. Among several leadership posts, he is the immediate past chair of the AIAA Aerodynamic Measurement Technology Technical Committee, a leader within the NATO STO Air Vehicle Technology activity AVT-349 Non-Equilibrium Turbulent Boundary Layers in High Reynolds Number Flow at Incompressible Conditions, the lead P.I. for a NASA NRA project on turbulence modeling benchmark experiments, and a co-P.I. for a newly awarded NASA ULI project on supersonic transport propulsion.
