Experimental Study on the Local Extinction Mechanisms of Ethanol Spray Swirling Flames

Abstract

This seminar will present a detailed investigation of ethanol spray flames in a swirl-stabilised burner to reveal the underlying physics of local extinction. The non-reacting and reacting flows under stable and near-blow-off conditions were analysed. Experimentally, the particle imaging velocimetry (PIV) technique was employed to analyse the velocity fields and spray characteristics, while simultaneous planar laser-induced fluorescence (PLIF) of the OH radical was used to measure the flame structure.  The dynamics of local extinction in the spray swirling flame were elucidated, and three significant factors contributing to local flame extinctions have been validated, including droplet-chemistry interactions, droplet-flame interactions, and flame-turbulence interactions. Specifically, the extinction events are primarily initiated by fluctuations in the local mixture fraction near the flame front, high heat loss, and excessive stretch in the shear layer.

Speaker

Prof. Yi Gao obtained her PhD in Engineering from Friedrich-Alexander-Universität Erlangen-Nürnberg, Germany (2013). Following postdoctoral research at the University of Cambridge (2014-2016), she joined Shanghai Jiao Tong University in 2017 and received tenure in 2023.  Her research has focused on advancing novel laser diagnostic technologies and deepening fundamental scientific understanding in the fields of ignition and blow-off dynamics, combustion instability, and pollutant formation (e.g., soot and NOx). She serves on the Tellers Committee of the International Combustion Institute and as a committee member for the Hiroshi Tsuji Early Career Researcher Award. Currently, she also serves as the Associate Editor of the AIAA Journal and the Youth Editor of the Journal of Aerospace Power.