Dr. LEUNG Chi Kin, Randolph

Associate Professor, Department of Mechanical Engineering

Hong Kong Polytechnic University

报告时间：2015年10月15日星期四上午10:00

Date：      10:00am, Thursday, October 15, 2015

报告地点： 嘉定校区上海地面交通工具风洞中心212会议室

Venue：    212 Conference Room, Shanghai Automotive Wind Tunnel Center, Jiading Campus

联系人：  杨志刚 教授69589240

Contact:   Prof. Zhigang Yang 69589240

Abstract:

Accurate prediction of the acoustics of fluid-structure interaction is important in devising quietingdesigns for engineering systems equipped with extensive flow duct networks where the thin ductwall panels are in contact with the flowing fluid. The flow unsteadiness generates acoustic wavesthat propagate back to the source region to modify the flow process generating them. Meanwhilethe unsteady flow pressure excites the thin panels to vibrate, which in turn modifies the flow processes. Evidently a strong coupling between the fluid aeroacoustics and the panel structural dynamics exists. Such coupled physical processes have to be thoroughly understood; otherwise, effectivequieting design is never achieved. This seminar reports the recent development of a time-domain direct numericalsimulation methodology for resolving the nonlinear aeroacoustic-structural interaction experienced by an elastic panel in a duct carrying a uniform mean flow. With no mean flow,the numerical results agree well with existing theories and reveal the physics of duct transmissionloss. Different types of aeroacoustic-structural interaction are identified when the duct flow velocity increases. Insight in the underlying physics of ducttransmission loss at different velocities are highlighted and discussed.

Short Bio:

Dr. Leung is an Associate Professor at the Department of Mechanical Engineering, The Hong Kong Polytechnic University, Hong Kong (PolyU). His research interest is in the broad area of engineering acousticswhich primarily coversaeroacoustics, flow-induced sound and structural vibration, diagnostics and control for product noise and vibration, product sound quality design. He received his BEng in Mechanical Engineering in 1992 and PhD in Fluid Dynamics and Acoustics in 1997, both from The University of Hong Kong. He then continued his postdoctoral research in the acoustics of marine gas turbine exhaust system at the Department of Engineering, University of Cambridge, U.K. in 1998 and flow-induced vibration of turbine blade at the Department of Mechanical Engineering, PolyU in 1999. Afterwards, he moved to industry and took up a sound engineer position at Emerson Climate Technologies, supporting the sound and vibration design for reciprocating/scroll refrigeration compressors and systems for the business in Asia-Pacific region. Apart from extensive teaching and research activities, he also actively provides consultancy servicesto the industry in the areas of fluid engineering, and control of noise and vibration