Experimental Tests and Aeroacoustic Simulations of the Control of Cavity Tone by Plasma Actuators

Applied Sciences

卷:7

Isamu Tanimoto¹  Akiyoshi Iida¹  Hiroshi Yokoyama¹ 

[1] Department of Mechanical Engineering, Toyohashi University of Technology, Toyohashi 441-8580, Japan;

关键词: cavity tone;    direct aeroacoustic simulation;    aeroacoustics;    plasma actuators;    flow control;    noise control;    vortices;    wind tunnel experiments;    acoustic sources;   

DOI  :  10.3390/app7080790

来源: DOAJ

【 摘 要 】

A plasma actuator comprising a dielectric layer sandwiched between upper and lower electrodes can induce a flow from the upper to lower electrode by means of an externally-applied electric field. Our objective is to clarify the mechanism by which such actuators can control the cavity tone. Plasma actuators, with the electrodes elongated in the streamwise direction and aligned in the spanwise direction, were placed in the incoming boundary of a deep cavity with a depth-to-length ratio of 2.5. By using this experimental arrangement, the amount of sound reduction (“control effect”) produced by actuators of differing dimensions was measured. Direct aeroacoustic simulations were performed for controlling the cavity tone by using these actuators, where the distributions of the body forces applied by the actuators were determined from measurements of the plasma luminescence. The predicted control effects on the flow and sound fields were found to agree well with the experimental results. The simulations show that longitudinal streamwise vortices are introduced in the incoming boundary by the actuators, and the vortices form rib structures in the cavity flow. These vortices distort and weaken the two-dimensional vortices responsible for producing the cavity tone, causing the tonal sound to be reduced.

【 授权许可】

Unknown