Abstract
A flow resonance accompanied by the emission of acoustic tones occurs in an over-expanded convergent-divergent (C-D) nozzle when operated at comparatively low pressure ratios. This phenomenon is distinguished from conventional screech tones and is referred to as “transonic tones”. In contrast to screech tones, the peak resonant frequency for transonic tones increases with pressure ratio; the peak sound pressure level exceeds 110 dB. In this study, we investigated the basic characteristics of transonic resonance and tones using a circular C-D nozzle in an anechoic room. The effects of the boundary layer trip were also evaluated using a tripping wire for the suppressing transonic resonance and tones. The results of acoustic measurements show that several predominant peaks correspond to transonic tones. However, the boundary layer trip inside the nozzle effectively eliminated these tones and suppressed the unsteadiness of the flow inside the nozzle.
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References
Powell, A.: On the mechanism of choked jet noise, Proceedings of the Royal Society of London, B66, 1953: 1039–1056.
Powell, A: On the noise emanating from a two-dimensional jet above the critical pressure, Aeronautical Quarterly, IV, Part II, 1953: 103–122.
Raman, G.: Supersonic Jet Screech: Half-century from Powell to the present, Journal of Sound and Vibration, 1999, 225(3): 543–571.
Shen, H., Tam, C. K. W.: Three-Dimensional Numerical Simulation of the Jet Screech Phenomenon, AIAA Journal, 2002, 40(1): 33–41.
Loh, C. Y., Hultgren, L. S., Jorgenson, P. C. E.: Near Field Screech Noise Computation for an Underexpanded Jet by the CE/SE Method, AIAA paper 2001: 2001–2252.
Zaman, K. B. M. Q., Dahl, M. D., Bencic, T. J., Loh, C. Y.: Investigation of a ‘transonic resonance’ with convergent- divergent nozzles, Journal of Fluid Mechanics, 2002, 463: 313–343.
Ishibashi, R., Anyoji, M., Handa, T., Aoki, T., Tsuru, D.: Study on Transonic Tone in Two-Dimensional Convergent- Divergent Nozzle, Proceedings of JSME Fluids Engineering Conference, Tokyo, (2015), in Japanese.
Zaman, K. B. M. Q., Papamoschou, D.: Study of Mixing Enhancement Observed with a Co-annular Nozzle Configuration, AIAA paper 2000: 2000–0094.
Acknowledgment
We would like to sincerely thank Prof. T. Aoki and Dr. D. Tsuru for their help and advice. We would also like to thank M. Harada, who is a current graduate student at Kyushu University, for his support in our experiments.
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Anyoji, M., Tabaru, I. Effect of boundary layer trip on reduction of jet noise in over-expanded nozzle flow. J. Therm. Sci. 26, 448–452 (2017). https://doi.org/10.1007/s11630-017-0960-5
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DOI: https://doi.org/10.1007/s11630-017-0960-5