Research Fellowin the Dept.ofMechanical Engineering,the Hong Kong Polytechnic University
Professor in the Dept.of Naval Architecture and Ocean Engineering, SouthChina University of Technology, Guangzhou
Small cavities suffering from noise can be found in broad fields of industry and military applications. Typical examples are cabins of surface and ground vehicles, nacelles of helicopters, and payload fairings of launch vehicles. These cavities exhibit the commonality of having small spatial dimensions of the interiors, which require noise control systems to be compactenoughto save the space occupied by the control system itself. Passive noise control techniques using acoustic resonatorsforlaunch vehicles and aircraft have been extensively evaluated in US, Hong Kong, Australia, India, and Korea since no distributed sensors, actuators, and extra power are needed and work stable. An integrable long T-shaped acoustic resonator(TAR)has been developed by Li and Vipperman for the interior noise control inapayload fairing ofan expendablelaunchvehicle. TheTARconsists of two mutually perpendicular tubes: a long closed-end tube and a short open-end tube. Compared with a conventional Helmholtz resonator,theadvantageof aTARis a large aspect ratio, which makes it easy to integrate into host structures to relax the space requirement. In this talk, the use of long T-shaped acoustic resonator array to tackle the low-frequency noise problems in small cavities will be systematically introduced,includingthe resonator design, structural-acoustic vibration modeling, control effectiveness study, control optimization, engineering criteria for practical implementation,anda couple of applications in civil and military projects.
Dr. Deyu Li received his B.S. degree in civil engineering from Wuhan University of Hydraulic and Electric Engineering,Wuhan,in 1986, received his M.S. in solid mechanics fromTsinghuaUniversity,Beijing,in 1992, and received his Ph.D. degrees in mechanical engineering fromUniversity of Pittsburgh,Pennsylvania,in 2003. Dr. Li has more than 15 years of experience in the fields of structural acoustics and vibrations and vibration and noise controls inChina,Hong Kong, andtheUSA. He has worked on number of industrial and military projects, including vibration and noise control of advanced grid-stiffened structures and ChamberCore cylindrical composite payload fairings for launch vehicles, development of acoustically intelligent surface for Army’s command communication center installed on a HMMWV, development of smart vibration isolation systems for gun system installed on Apache helicopters, noise transmission control of double panel partitions, noise control in small enclosures, quantification of window-reveal isolation for aircraft noise transmission and so on. He has been a Research Fellow in the Department of Mechanical Engineering in the Hong Kong Polytechnic University since June 2004, and he is also a professor in the Department of Naval Architecture and Ocean Engineering in South China University of Technology in Guangzhou, where he is working on the fields of underwater acoustics, structural acoustics and vibrations, smart structures and adaptive systems, active vibration and noise controls, and real-time system identification.