Kweon Y., Miyazato Y., Aoki T., Kim H., Setoguchi T.

The present study describes an experimental work to control supersonic jet noise using a mesh screen that is placed at the nozzle exit plane. The jet pressure ratio is varied to obtain the supersonic jets which are operated in a wide range of over-expanded to moderately under-expanded conditions. The mesh screen has a wire diameter of 0.45mm and an aperture size of 1.16mm¡¿1.16mm. In order to perturb mainly the jet shear layer, the inner diameter size of a mesh screen is changed. In the present study, the effect of an inner diameter of a mesh screen on the jet structure and sound generation are examined. 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 for controlling supersonic jet noise is discussed in detail. Furthermore, the present experimental results for the mesh screen are also compared with both the cases of tabs and a wire device.