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Seminar - Ligament formation mechanism and breakup threshold for the Faraday instability by Dr. Yikai Li
日期:2017 年 08 月 02 日 ( 星期三)
Time:11:00 am – 12:00 pm
Venue:EF305

Abstract:

Faraday instability is an important approach to trigger the liquid surface wave patterns and resultant atomization. The mechanism of the surface ligament formation aroused by Faraday instability and the threshold forcing acceleration to invoke breakup will be discussed in this talk. Based on a numerical simulation for a prototype Faraday instability flow, the nonlinear dynamics associated with the ligament formation are analyzed in detail. A local maximum pressure location at the surface crest root induced by the impinging of the liquid flow from the trough portions is found to play an essential role in generating a slender ligament. The predominant surface wave mode which grows with the largest rate is determined and a novel numerical strategy is proposed to study the threshold condition for spray formation based on a cell model. The results show that the onset of a spray (or breakup) occurs in the subharmonic unstable region for a dimensionless acceleration ~O(1), which is nearly two orders larger than the experimental result.

Bio-sketch:

Dr. Li received his Bachelor’s and Master’s degrees in Thermo-physics Engineering from Beijing University of Aeronautics and Astronautics, China, in 2008 and 2010, respectively. He received his Ph.D. degree in Aerospace Engineering from Nagoya University, Japan, in 2014. Dr. Li has been serving as a lecturer at Beijing Institute of Technology since 2015. His research interests include numerical techniques for simulating liquid-gas flows and the mechanisms of hydrodynamic instabilities.