Days Hours Minutes Seconds

The International Conference on
Aerospace System Science and

JULY 06-07, 2023


Keynote speech

Tom Shih
Professor of School of Aeronautics and Astronautics,
Purdue University
Research Interest: CFD / HT, gas turbine cooling technology, aircraft icing and control technology of shock / boundary layer interaction.

Speech Title: Hybrid LES-RANS with an Adaptive Downstream RANS Model

Abstract: Turbulence pervades most flows of engineering interest, and its prediction remains a challenge on both accuracy and cost.  One promising predictive approach that reduces cost combines large-eddy simulation (LES) with simulation based on Reynolds Averaged Navier-Stokes equations (RANS).  This talk presents a method that overcomes stability and accuracy issues associated with hybrid LES-RANS methods. The method developed involves extracting the Reynolds stresses from the upstream LES solution and then using that information to convert the downstream RANS model from a scalar eddy-viscosity model to an anisotropic nonlinear eddy-viscosity model. The method developed was evaluated by computing film cooling of a flat plate with the coolant injected through one row of circular holes.  Results obtained show instabilities at the LES-to-RANS interface to be eliminated.  Also, the method developed yielded solutions that compare reasonably well with those from LES, even though a significant portion of the flow is computed by the adapted anisotropic RANS model instead of LES, which significantly reduced the number of grid points needed and the computational time.  Since modification of the downstream RANS model is based on information extracted from the upstream LES solution, the method developed is adaptive to the problem being studied.

Tom I-P. Shih is professor of aeronautics and astronautics (head of the School of Aeronautics and Astronautics, 2009–2019) and professor, by courtesy, of mechanical engineering at Purdue University. Prior to joining Purdue, he was a mechanical engineer at NASA Lewis (now Glenn) Research Center and served on the faculties of the University of Florida, Carnegie Mellon University, Michigan State University, and Iowa State University (chair of the Dept. of Aerospace Engineering, 2003–2009).  Currently, he is the editor-in-chief of the AIAA Journal and serves on the advisory boards of the Department of Mechanical Engineering at The University of Michigan, the Department of Mechanical Engineering at Michigan State University, and the Dept. of Mechanical, Materials, and Aerospace Engineering at Illinois Institute of Technology and on the review board of the Air Force Research Laboratory's Collaborative Center for Aeronautical Sciences.  Previously, he also served on the Aeronautics Committee of the NASA Advisory Council (2018-21) and chaired AIAA Committee on Higher Education (2016-23) and the Aerospace Department Chair Association (2005-06).  Tom started his undergraduate education at West Virginia University, but completed his B.S. at the National Cheng Kung University in Taiwan. His M.S.E. and Ph.D. degrees are from the University of Michigan at Ann Arbor. He is a Fellow of American Institute of Aeronautics and Astronautics (AIAA) and the American Society of Mechanical Engineers (ASME) and received the 2010 Distinguished Engineering Educator Award from the Engineers’ Council of San Fernando Valley, the  2015 AIAA Energy Systems Award, and the 2020 AIAA Thermophysics Award.