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Control of the Supersonic Jet Noise Using a Wire Device

The present study describes an experimental work to reduce supersonic jet noise using a control wire device that is placed into the supersonic jet stream. 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 wire device is composed of long cylinders with a very small diameter. X-type wire device is applied to control the supersonic jet noise, and its location is varied to investigate the effect of the control wire device on supersonic jet noise. A high-quality Schlieren optical system is used to visualize the flow field of supersonic jet with and without the control wire device. Acoustic measurement is performed to obtain the overall sound pressure level and noise spectra. The results obtained show that the present wire device destroys the shock-cell structures, reduces the shock strength, and consequently leading to a substantial suppression of supersonic jet noise.