Recent Advances in Modeling Swirl Dominated Phenomena
11/12/2012, 3:10 pm - 4:10 pm
Joseph C. Majdalani, Ph.D., P.E.
H. H. Arnold Chair of Excellence in Advanced Propulsion
Department of Mechanical, Aerospace and Biomedical Engineering
The University of Tennessee Space Institute
This talk will focus on the effective use of unidirectional an bidirectional swirl mechanisms in a variety of applications involving propulsive systems such as the Vortex Injection Hybrid Rocket Engine (VIHRE), the self-cooled Vortex Combustion Cold Wall Chamber (VCCWC), the Vortex-Swept Hybrid Rocket Engine, the Liquid Detonation Pulse Engine, etc. Our discussion will extend to the modeling of high-speed compressible motions as well as atmospheric flows, such as tornadoes, hurricanes, waterspouts, etc. Special emphasis will be placed on modeling the VCCWC, a LOX-propane vortex-driven thrust engine that incorporates the fundamental features of a cyclone. The resulting bidirectional/bipolar vortex confines chemical reactions and hot combustion products to its core region, where the gaseous mixtures remain completely surrounded by an outer layer of freshly injected, low-temperature oxidizer. Naturally, the film-cooling effect that accompanies the oxidizer steam reduces thermal loading and overall engine weight. Furthermore, the spiraling motion of the reactants increases both mixing and fuel residence time to the extent of promoting higher combustion efficiency. The bidirectional vortex concept was first implemented in cyclone separators and later applied to hybrid and liquid thrust engines. Several recent breakthroughs in describing the observed helical behavior will be overviewed, and these will include new classes of complex-lamellar and Beltramian motions for vortex engine flowfields with arbitrary headwall injection. The talk will conclude with recent stability analyses that can accurately predict vorticoacoustic waveforms in a given combustor, and these will confirm the role of swirl as a stabilizing flow agent.
Dr. Majdalani received his PhD in Mechanical Engineering from the University of Utah in 1995. Between 1997 and 2003, he served as Assistant and then Associate Professor with tenure in the Department of Mechanical Engineering at Marquette University, Milwaukee, WI. In 2002, he received an NSF CAREER Award and joined the University of Tennessee Space Institute, serving as the Jack D. Whitefield Professor of High Speed Flows. In 2007, he was appointed H.H. Arnold Chair of Excellence in Advanced Propulsion.
Dr. Majdalaniís research devotes itself to the theoretical and computational modeling of internal flow fields associated with energy and propulsion systems including injection and swirl-driven combustion chambers. His interests span thermo-acoustic instabilities, engine internal flowfields, vorticity dynamics, and singular perturbation theory. His research activities since 1997 have materialized in over 220 publications in journals, book chapters, and conference proceedings. His work on core flow modeling of liquid, solid, and hybrid rocket engines has led to the discovery of new solutions to describe cyclonic motions in self-cooled liquid and hybrid thrust engines, centrifuges, hurricanes, and other injection-driven flowfields. Recently, his work on compressible gas motions has required the development of a new framework for solving multi-dimensional high-speed flow problems.
Dr. Majdalani is presently a Fellow of ASME, Associate Fellow of AIAA, Associate Editor of the International Journal of Energetic Materials and Chemical Propulsion (Begell House), AIAA Instructor for two short courses, and Chair of Education within the AIAA Hybrid Rocket Technical Committee.
Monday, November 12, 2012
3:10 p.m., 134 FGH
Refreshments at 2:45-3:00 p.m. in the Student Lounge Olin Hall