2340 超音速噴流騒音に及ぼすメッシュスクリーン装置の影響に関する研究(S46-2 圧縮性流れの基礎と応用(超音速流2),S46 圧縮性流れの基礎と応用)  [in Japanese] 2340 The Effect of a Mesh Screen Device on Supersonic Jet Noise  [in Japanese]

This paper describes an experimental work to reduce supersonic jet noise using a mesh screen device that is placed at the nozzle exit plane. In order to perturb mainly the jet shear layer, the inner diameter size of a mesh screen device is changed. The effect of an inner diameter of a mesh screen device on the jet structure and sound generation is experimentally investigated. A high-quality Schlieren optical system is used to visualize the flow field of supersonic jet with and without the mesh screen. Acoustic measurement is performed to obtain the overall sound pressure level and noise spectra. Based upon the results obtained, the effectiveness of the mesh screen device for reducing supersonic jet noise is discussed in detail. Furthermore, the present results for the mesh screen are also compared with the cases of tabs and a wire device.