Contact Info
Department of Applied Mathematics
University of Waterloo
Waterloo, Ontario
Canada N2L 3G1
Phone: 519-888-4567, ext. 32700
Fax: 519-746-4319
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Thursday, April 2, 2015 3:30 PM EDT
MC 5417
Speaker
J.M.Floryan
Department of Mechanical and Materials Engineering
The University of Western Ontario
Title
Certain aspects of flows over rough surfaces
Abstract
It has been recognized since the pioneering experiments of Reynolds in 1883 that surface roughness plays a significant role in the dynamics of shear layers. This is a classical problem in fluid dynamics but, nevertheless, its resolution is still lacking. It is believed that the flow dynamics in the case of spanwise two-dimensional roughness is driven by the inflectional velocity profiles associated with flow separation behind the roughness. It is thought that the horse shoe vortex that wraps around a single isolated roughness dominates the flow response in this case. It is not known what mechanisms are induced by the distributed roughness. Most of the efforts in the last case have been focused on the experimental approaches that resulted in a number of correlations but failed to uncover the mechanisms responsible for the flow response. Theoretical analyses also failed to provide a consistent explanation of the dynamics of the flow. As there is an uncountable number of possible geometrical roughness forms, it appears that it is not possible to find a general answer and the problem formulation represents a logical contradiction, i.e., it is not possible to find a general answer to a problem that has an uncountable number of variations. The recent progress towards the theoretical resolution of this apparent contradiction will be discussed and recent results dealing with the problem of distributed surface roughness will be presented. Developments in the area of the reduced geometry model, immersed boundary conditions method as well as generalized stability theory will be briefly discussed, including experimental verification of some of the theoretical predictions.
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Dr. Jerzy M Floryan is a professor and head of Department of Mechanical and Materials Engineering at the University of Western Ontario in Canada. He received PhD from Virginia Tech, US, and postdoctoral training from the Northwestern University, US. He is Fellow of the American Society of Mechanical Engineers, Canadian Society of Mechanical Engineers, Canadian Aerospace and Space Institute, Engineering Institute of Canada and Japanese Society for the Promotion of Science, and Associate Fellow of the American Aeronautics and Space Institute. He has been awarded Humboldt Research Prize in Germany, Senior NATO Research Award in France, Science and Technology Fellowship in Japan and Humboldt Fellowship in Germany. His Canadian awards include Robert W. Angus Medal (Engineering Institute of Canada) and Canadian Pacific Railway Engineering Medal (Canadian Society of Mechanical Engineers). He is also Canadian delegate to IUTAM. Dr.Floryan has held visiting appointments at the Los Alamos National Laboratory (US), German Aerospace Research Establishment (DVLR, Gottingen), French Aerospace Research Establishment (CERT-ONERA, Toulouse), National Aerospace Laboratory (Tokyo, Japan), Paul Sabatier University (Toulouse, France), Ohio University (USA) and the National University of Singapore (Singapore).