Abstract
Prediction of combustion of gaseous mixtures described by detailed kinetics and multicomponent transport is notoriously difficult due to the multiscale nature of the phenomena. For common mixtures such as hydrogen-air at atmospheric pressure, it will be rigorously shown that the finest continuum reaction length scales are a few microns and are well predicted by a simple estimate from Maxwellian diffusion analysis. The coarsest reaction length scales are typically several orders of magnitude larger. Both fine and coarse reaction scales are usually dwarfed by geometric scales of an associated engineering device. For flows characterized by a finite number of thin fronts, a computational strategy for achieving a fully verified, direct numerical simulation (DNS) solution in a demanding multiscale environment is demonstrated. The strategy is based upon a massively parallel implementation of an adaptive algorithm built with the aid of a wavelet-based representation of all state variables in the flow field. Results are shown for inert and reactive compressible multi-dimensional Navier-Stokes models.

Bio
JOSEPH M. POWERS, Professor of Aerospace and Mechanical Engineering and Concurrent Professor of Applied and Computational Mathematics and Statistics at the University of Notre Dame, received his B.S., M.S., and Ph.D. degrees in mechanical engineering from the University of Illinois at Urbana-Champaign in 1983, 1985, and 1988, respectively. His research interests include computational mechanics, scientific computing, detonation theory, pyrotechnic combustion, high-speed propulsion, transition to detonation in solid propellants, high-speed flows in reactive porous media, numerical and theoretical methods for multiscale phenomena, and systematic reduction of large systems of chemical kinetics. He is the author of several papers in the archival literature and has supervised many M.S. and Ph.D. students since joining the faculty in 1989. He has held summer appointments at NASA John H. Glenn Research Center at Lewis Field, the U.S. Air Force Wright Laboratories at Eglin Air Force Base, Los Alamos National Laboratory, Argonne National Laboratory, and the Chinese Academy of Sciences. He is the recipient of the University of Notre Dame's Amoco College of Engineering Outstanding Teacher of the Year Award in 1994, the Department Faculty Award in 1997, the 2006-2007 Kaneb Faculty Fellowship, and the 2010 Ruth and Joel Spira Teaching Award. He received a NASA Innovative Technology Award in 1999. He has served several terms as Associate Editor of the Journal of Propulsion and Power. Dr. Powers is a Member of American Physical Society, Society for Industrial and Applied Mathematics, American Society of Mechanical Engineers, the Combustion Institute. He is an Associate Fellow of the AIAA.

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