A Perspective on Transition Modeling in Computational Fluid Dynamics

Speaker: Jim Coder, University of Tennessee, Knoxville
July 20, 2017

Presentation

Abstract

There is an ever-growing demand for laminar-turbulent transition modeling capabilities in production computational fluid dynamics (CFD) solvers. Popular examples of classical, non-CFD methods for predicting transition include local-correlation models and linear-stability theory; however, these methods are based on integral boundary-layer properties not explicitly available in CFD calculations. Evaluating these quantities generally requires non-local search and/or integration operations, which is incompatible with massive parallelization and arbitrary geometries. It is instead desirable to model transition using locally defined advection-diffusion-type PDEs similar to those used to model turbulence. This enables compatibility with existing solver algorithms and parallelization strategies. An overview of several such transition models and their underlying physics will be presented, including the amplification factor transport model, developed by the author, that incorporates the eN method of linear stability theory in a CFD-compatible framework. Application of this model to a wide range of problems, including fixed-wing aircraft, high-lift configurations, rotorcraft, and hypersonic flow will be presented. Planned future developments, including integration with new turbulence modeling strategies and new flow-solver paradigms, will be discussed.

Biography

Jim Coder is an Assistant Professor of aerospace engineering in the Mechanical, Aerospace and Biomedical Engineering (MABE) department at the University of Tennessee, Knoxville. His research focuses on computational aerodynamics using RANS and hybrid RANS/LES methodologies, and includes advanced turbulence/transition model development, simulation of unsteady rotorcraft flows, hypersonic SBLI, and aerodynamic design optimization. He is currently leading a team under NASA’s University Leadership Initiative focusing on Ultra-Efficient Commercial Vehicles. Coder is a senior member of the American Institute of Aeronautics and Astronautics, serving as a member of their Applied Aerodynamic Technical Committee, and leading the APATC Education Subcommittee and the APATC CFD Transition Modeling Discussion Group. He is also a member of the American Helicopter Society.

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