Dynamics of Vortices in Unsteady Flames

Abstract

The emergence of vortices in fluid is usually a manifestation of hydrodynamic instability. In combustion, the reacting flow is also susceptible to various types of instabilities, which may give rise to vortex formation. The subsequent vortex-flame interactions can strongly influence the flame structures and dynamical features and pose serious challenges to combustion stability. This motivated us to study the dynamics of vortices in unsteady flames by focusing on two fundamental questions: 1) how does flame influence the formation and behaviors of vortices and 2) how do vortices affect the flame dynamics? To this end, Prof. Xia employed time-resolved laser diagnostics to simultaneously capture the evolutions of coherent vortical and flame structures. Prof. Xia will demonstrate how such diagnostics and analysis can help advance our understanding of vortex and flame dynamics, through several examples of jet diffusion flames and premixed swirling flames. 

Speaker

Prof. Xi Xia is an Associate Professor at Shanghai Jiao Tong University (SJTU). He obtained his PhD from the University of Florida in 2016 and was a postdoctoral research fellow at PolyU during 2017-2018. His research revolves around vortex dynamics and aerodynamics for unsteady problems of both non-reacting and reacting flows. He has published more than 40 peer-reviewed papers in leading journals, such as Proceedings of the National Academy of Sciences (PNAS), Journal of Fluid Mechanics, Combustion and Flame, etc.