Proceedings of the Korean Society of Propulsion Engineers Conference (한국추진공학회:학술대회논문집)
- 2008.03a
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- Pages.622-627
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- 2008
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- 1975-342X(pISSN)
Experimental Investigation of Supersonic Jet Noise Reduction Using Microjet Injection
- Mamada, Ayumi (Department of Aeronautics and Astronautics, School of Engineering, University of Tokyo) ;
- Watanabe, Toshinori (Department of Aeronautics and Astronautics, School of Engineering, University of Tokyo) ;
- Uzawa, Seiji (Department of Aeronautics and Astronautics, School of Engineering, University of Tokyo) ;
- Himeno, Takehiro (Department of Aeronautics and Astronautics, School of Engineering, University of Tokyo) ;
- Oishi, Tsutomu (IHI Corporation)
- Published : 2008.03.30
Abstract
Experiment of active noise control on supersonic jet noise was conducted by use of microjet injection. The microjets were injected to the shear layer of the main jet through 22 small holes at the lip of a rectangular nozzle. Based on the measurement of farfield sound pressure, it was found that the jet noise was effectively reduced by several dB(in some cases up to 10 dB). The power levels of all measurement points were also reduced by use of microjet injection. The microjet affected not only the broadband noise but also the screech tone noise. The sound pressure level, the frequency of the screech tone, and the structure of the jet could be changed by the microjet. Flow visualization with schlieren technique was also made to observe the effect of microjet on the flow field.