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Prof. James J. Feng
Canada Research Chair in Complex Fluids and Interfaces
University of British Columbia (UBC), Canada |
Abstract: A three-phase contact line forms when a gas-liquid interface intersects a solid substrate, and a moving contact line presents a well-known singularity that cannot be computed using the conventional Navier-Stokes formalism. I will discuss the use of a diffuse-interface model for computing moving contact lines. The Cahn-Hilliard diffusion is known to regularize the singularity and makes possible a continuum-level computation. But relating the results to physical reality is subtle. I will show numerical results that suggest a well-defined sharp-interface limit, with a finite contact line speed that can be related to measurements. Then I will discuss two applications: enhanced slip on textured substrates and propulsion of water striders on the air-water interface. In each case, the diffuse-interface model provides new physical insights into the hydrodynamics underlying novel phenomena.
About the Speaker: James J. Feng received his B.S. (1985) and M.S. (1988) degrees from Peking University in Beijing, and his Ph.D. (1995) from the University of Minnesota, all in Fluid Mechanics. After a postdoctoral stint at the University of California, Santa Barbara, he was appointed an associate professor at the Levich Institute for Physicochemical Hydrodynamics in New York City, where he carried out research in non-Newtonian fluid dynamics and polymer rheology and taught in the Mechanical Engineering department of the City College of New York. In 2004, he moved to the University of British Columbia (UBC) in Vancouver, Canada, as a Canada Research Chair in Complex Fluids and Interfaces, with a joint appointment in Chemical and Biological Engineering and Mathematics. He was elected fellow of the APS (American Physical Society) in 2013 and appointed a Distinguished Scholar in Residence at the Peter Wall Institute for Advanced Studies at UBC for 2014-2015. His current research covers multiphase and interfacial fluid dynamics, cell and tissue mechanics and morphogenesis.
Date&Time: June 11, 2014 (Wednesday), 11:00 - 12:00 a.m.
Location: 606 Conference Room
