Charles Meneveau Professor, Department of Mechanical Engineering Johns Hopkins University, USA
New physics-based wall modeling concepts for Large Eddy Simulations of turbulence
Large Eddy Simulation (LES) of turbulent flows relies on subgrid-scale models as well as wall models. The latter are crucial to applications of LES to wall-bounded flows that do not use sufficiently fine resolution to capture the viscous sublayer physics of the flow. The traditional approach relies heavily on the notion of equilibrium turbulence physics. This notion, however, lacks proper justification in applications far from equilibrium conditions, such as when wall-bounded flows are subjected to rapid external changes. We have developed a new class of physics-based large eddy simulation wall models for more general applicability. The LaRTE (Lagrangian Relaxation To Equilibrium) model is based on a formal interpretation of quasi-equilibrium that governs the momentum balance integrated in the wall-normal direction. The new approach enables us to formally distinguish quasi-equilibrium from additional, non-equilibrium contributions to the wall stress. Additional physics such as fast developing laminar (Stokes) sublayers and effects of wall-attached eddies are modeled separately. The new multi-time scale (MTS) wall modelling approach is first tested in standard equilibrium channel flow, in wall modeled LES of channel flow with a suddenly applied spanwise pressure gradient (SSPG), in a channel flow with varying streamwise accelerations, in pulsating channel flows at various forcing frequencies, in boundary layer flow with a separation bubble, and flow over periodic 2D hills including wall curvature effects. The role of various time scales and model terms will be discussed. This work has been performed with Mitchell Fowler, Ho Jun Kim, and Tamer Zaki, and the research is funded by the Office of Naval Research (grant # N000142312185, Dr. Peter Chang, program manager).
Prof. Charles Meneveau
Charles Meneveau is the Louis M. Sardella Professor in the Department of Mechanical Engineering, is Associate Director of the Institute for Data Intensive Engineering and Science (IDIES) and is jointly appointed as Professor in the Department of Physics and Astronomy at Johns Hopkins University. He received his B.S. degree in Mechanical Engineering from the Universidad Técnica Federico Santa María in Valparaíso, Chile, in 1985 and M.S, M.Phil. and Ph.D. degrees from Yale University in 1987, 1988 and 1989, respectively. During 1989-1990 he was a postdoctoral fellow at the Center for Turbulence Research at Stanford. He has been on the Johns Hopkins faculty since 1990. His area of research is focused on understanding and modeling hydrodynamic turbulence, and complexity in fluid mechanics in general. The insights that have emerged from Professor Meneveau’s work have led to new numerical models for Large Eddy Simulations (LES) and applications in engineering and environmental flows, including wind farms. He also focuses on developing methods to share the very large data sets that arise in computational fluid dynamics. He is Deputy Editor of the Journal of Fluid Mechanics and has served as the Editor-in-Chief of the Journal of Turbulence. Professor Meneveau is a member of the US National Academy of Engineering, a foreign corresponding member of the Chilean Academy of Sciences, a Fellow of APS, ASME, AMS and recipient of the Stanley Corrsin Award from the APS, the JHU Alumni Association's Excellence in Teaching Award, and the APS' François N. Frenkiel Award for Fluid Mechanics.