Lagrangian Evolution and Modeling of Velocity Gradient Tensor and Particle Dynamics in Fluid Turbulence
Speaker: Charles Meneveau, Johns Hopkins University
Department: Mechanical & Aerospace Engineering
Location: Bowen Hall Auditorium 222
Date/Time: Friday, November 8, 2013, 3:30 p.m. - 4:30 p.m.
We recall several well-known geometric aspects of the velocity gradient tensor in turbulent flows, such as vorticity strain-rate relative alignments and preferred eigenvalue states. The data used in the analysis shown is obtained mostly from numerical simulations of isotropic turbulence, typically using on the order of 10^9 degrees of freedom. Conversely, we describe a Lagrangian model based on only 8 stochastic differential equations that reproduces many of the observed geometric and statistical features of the velocity gradient tensor. We show that the model reproduces two-time correlations between vorticity and strain-rate. The model can also be used to characterize the tumbling rates of small rigid anisotropic particles as well as the statistics of deformations of small drops transported by turbulent flows. The work presented has been performed in collaborations with Drs. L. Chevillard, L. Biferale and R. Verzicco, and is funded by the US National Science Foundation.
Charles Meneveau is the Louis M. Sardella Professor in the Department of Mechanical Engineering at Johns Hopkins University. He also has a joint appointment in the Geography and Environmental Engineering Department and serves as deputy director of the Institute for Data Intensive Engineering and Science (IDIES) at Johns Hopkins. 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 1989/90 he was a postdoctoral fellow at the Stanford University/NASA Ames' Center for Turbulence Research. Professor Meneveau 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. He combines experimental, computational and theoretical tools for his research. Special emphasis is placed on the multiscale aspects of turbulence, using appropriate tools such as subgrid-scale modeling, downscaling techniques, fractal geometry, wavelet analysis, and applications to Large Eddy Simulation. The insights that have emerged from Professor Meneveaus work have led to new numerical models for Computational Fluid Dynamics and applications in engineering and environmental flows. Recently, his research has emphasized applications to wind energy and the creation and curation of large-scale databases for turbulence research. With his students and co-workers, he has authored over 160 peer-reviewed articles. In 2005 the ISI has recognized the article Scale Invariance and Turbulence Models for LES" (2000, with J. Katz) as a "Highly Cited Article", placing it in the top 1% within its field. Professor Meneveau is a foreign corresponding member of the Chilean Academy of Sciences, and a Fellow of the American Academy of Mechanics, the U.S. American Physical Society and the American Society of Mechanical Engineers. He received the inaugural Stanley Corrsin Award from the American Physical Society (2011), the 2011 J. Cole Award from AIAA, the 2004 UCAR Outstanding Publication award (with students and other colleagues at JHU and NCAR), the Johns Hopkins University Alumni Association's Excellence in Teaching Award (2003), and the APS' François N. Frenkiel Award for Fluid Mechanics (2001). He is now Deputy Editor of the Journal of Fluid Mechanics, and the Editor-in-Chief of the Journal of Turbulence. In the past, he has served as Associate Editor for the Journal of Fluid Mechanics, as member of the Editorial Committee of the Annual Reviews of Fluid Mechanics and as an Associate Editor for Physics of Fluids.