Experiment of the effect of nozzle spacing on twinjet screech tones
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摘要: 实验详细测量了完全膨胀马赫数范围为110~160、喷管间距为16到32倍喷管出口直径的超声速双喷流近声场,分析了两个喷流各自发出的啸音在近声场的相位关系,研究了喷管间距对双喷流耦合的影响。结果表明:对比单喷流,双喷流耦合啸音在A模态时,呈现出反对称或对称模式,在反对称模式下,喷管中间区域啸音强度减小,对称模式下,双喷流中间区域啸音强度略大于单喷流啸音;B模态时,两个处于摆动模态的喷流啸音在喷管中间区域同相而发生耦合,极大地增强了B模态的幅值,达到160dB;C模态的相位关系还需进一步研究。对比不同喷管间距下的双喷流近声场,发现喷管间距过小或过大均不利于B模态的耦合;喷管间距对C模态影响最大,当喷管间距变大时,C模态幅值及主导马赫数范围均增大。Abstract: The near field of the supersonic twinjet noise was measured experimentally with fully expanded Mach number ranging from 110 to 160 and nozzle spacing from 16-32 times of nozzle outlet diameter. The phase difference of the near field screech tones radiated from the two jets was analyzed in detail, and the effect of nozzle spacing on the coupling of the twinjet was explored. The experimental results showed that there were two different patterns for the A mode of twinjet screech tone, ie:symmetric and antisymmetric along the central plane of the two nozzles. In the antisymmetric mode, the intensity of the screech tone in the internozzle region decreased, which was slightly larger than the amplitude of the single jet in the symmetric mode. For the twinjet operating in B mode, the screech tone generated by the two jets were in phase in the internozzle region, which reinforced the oscillation of the twinjet, and the amplitude of the screech tone in the internozzle region can reach to 160dB. The phase difference of the C mode needs further study. Comparing the results with different nozzle spacing, it was found that the coupling was suppressed for the B mode when the nozzle spacing was larger or smaller, while both the amplitude and the dominant Mach number range of the C mode increased with the nozzle spacing.
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Key words:
- supersonic twinjet /
- screech tone /
- coupling /
- phase difference /
- nozzle spacing
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[1] BERNDT D E.Dynamic pressure fluctuations in the internozzle region of a twin jet nacelle[R].SAE Technical Paper 841540,1984. [2] HARPERBOURNE M,FISHER M J.The noise from shock waves in supersonic jets[C]∥Proceedings of Agard Conference on Noise Mechanisms.Brussels:AGARD,1973:1-13. [3] POWELL A.On the mechanism of choked jet noise[J].Proceedings of the Physical Society,1953,66(12):1039-1056 [4] TAM C K W,SEINER J M,YU J C.Proposed relationship between broadband shock associated noise and screech tones[J].Journal of Sound and Vibration,1986,110(2):309-321. [5] RAMAN G.Advances in understanding supersonic jet screech[J].Progress in Aerospace Sciences,1998,34(1/2):45-106. [6] RAMAN G.Supersonic jet screech:halfcentury from powell to the present[J].Journal of Sound and Vibration,1999,225(3):543-571. [7] SEINER J M,MANNING J C,PONTON M K.Dynamic pressure loads associated with twin supersonic plume resonance[J].AIAA Journal,1986,26(8):954-960. [8] SEINER J M,MANNING J C,CAPONEF J,et al.Study of external dynamic flap loads on a 6 percent B1B model[J].Journal of Engineering for Gas Turbines and Power,1991,114(4):816-828. [9] NORUM T D,SHEARIN J H.Dynamic loads on twin jet exhaust nozzles due to shock noise[J].Journal of Aircraft,1986,23(9):728-729 [10] WLEZIEN R W.Nozzle geometry effects on supersonic jet interaction[J].AIAA Journal,1989,27(10):1361-1367. [11] ALKISLAR M B,KROTHAPALLI A,CHOUTAPALLI I,et al.Structure of supersonic twin jets[J].AIAA Journal,2005,43(11):2309-2318. [12] TAM C K W,SEINER J M.Analysis of twin supersonic plume resonance[R].AIAA 87-2695,1987. [13] MORRIS P J.Instability waves in twin supersonic jets[J].Journal of Fluid Mechanics,1990,220:293-307. [14] GAO Junhui,XU Xin,LI Xiaodong.Numerical simulation of supersonic twinjet noise with high order finite difference scheme[R].AIAA2016-2938,2016. [15] SHAW L.Twinjet screech suppression[J].Journal of Aircraft,1990,27(8):708-715. [16] SEINER J M,JANSEN B,MURRAY N.Aeroperformance efficient noise suppression of a supersonic model twin jet nacelle[R].AIAA2009-3130,2009.
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