Buffeting Phenomenon of Openjet Automotive Aeroacoustic Wind Tunnel

Abstract:

Based on a 1/15 model wind tunnel of the Shanghai Automotive Wind Tunnel Center,an experimental study is made of the buffeting phenomenon of openjet wind tunnel on the basis of three limiting configurations in charge of the vortex of nozzle (source of noise),feedback of collector and the structure of plenum,respectively.A comparative study of the spectrum of sound pressure，coefficient of pressure pulsation and movements of frequency that shifted with wind speed and where buffeting occurs,reveals the coupling factors more clearly.For the wind tunnel model,the coupling factors of buffeting are as follows:vortex of nozzle excites the helmholtz resonation of plenum and is coupled with the acoustic modal of full circuit,and the selfexcited system,is resonated by the vortex of nozzle and the feedback of collector.