仿生学翼型尾缘锯齿降噪机理
收稿日期: 2014-08-26
修回日期: 2015-03-25
网络出版日期: 2015-04-09
基金资助
国家自然科学基金 (51276149);空气动力学国家重点实验室研究基金(SKLA20140201)
Noise reduction mechanism of bionic airfoil trailing edge serrations
Received date: 2014-08-26
Revised date: 2015-03-25
Online published: 2015-04-09
Supported by
National Natural Science Foundation of China (51276149); State Key Laboratory of Aerodynamics Research Fund (SKLA20140201)
采用大涡模拟与声类比的方法研究了尾缘锯齿对翼型自噪声的影响。以SD2030翼型为研究对象,设计的尾缘锯齿幅值为10%弦长,周期为4%弦长。模拟了来流速度为31 m/s、0° 攻角下直尾缘翼型与锯齿尾缘翼型的流场,对应的基于弦长的雷诺数约为310 000。详细分析了尾缘锯齿对翼型尾缘湍流流场的影响,并通过FW-H方程计算大涡模拟提取的声源项,得到直尾缘翼型与锯齿尾缘翼型的声场。研究发现,锯齿尾缘可以明显降低翼型中低频范围内的噪声,在4 000 Hz以下,窄带噪声最多可降低约16 dB。但尾缘锯齿对翼型气动性能有着不利影响。进一步研究表明,该状态下翼型噪声主要由层流边界层引起的涡脱落噪声主导,尾缘锯齿可以抑制层流边界层引起的涡脱落现象,降低翼型升力脉动与尾缘附近的表面压力脉动,减弱尾缘处的低频湍流脉动与涡量,并有效降低尾缘附近涡的展向相关性,这些因素的综合作用使得翼型自噪声降低。
仝帆 , 乔渭阳 , 王良锋 , 纪良 , 王勋年 . 仿生学翼型尾缘锯齿降噪机理[J]. 航空学报, 2015 , 36(9) : 2911 -2922 . DOI: 10.7527/S1000-6893.2015.0084
Large eddy simulation and acoustic analogy are performed to investigate the effects of trailing edge serrations on airfoil self-noise. A SD2030 airfoil is used for study. The trailing edge serrations' amplitude is 10% of airfoil chord while the serrations' wavelength is 4% of airfoil chord. The fluid field of SD2030 airfoil at 0° angle of attack with incoming flow velocity of 31 m/s is simulated and the corresponding Reynolds number based on airfoil chord is about 310 000.The effect of trailing edge serrations on the turbulence flow field near the airfoil trailing edge is analyzed in detail. Then FW-H equation is used to calculate the sound field of the straight/serrated trailing edge airfoil with the help of the sound source information obtained by the large eddy simulation. It is found that trailing edge serrations can significantly reduce airfoil noise in low to middle frequency range. The noise reduction can reach up to 16 dB in narrow band in the frequency range smaller than 4 000 Hz. However, the airfoil aerodynamic performance is adversely affected by the trailing edge serration. Further results show that the airfoil noise is dominated by laminar boundary layer-vortex shedding noise under the current condition. It is found that the trailing edge serrations can suppress the laminar boundary layer-vortex shedding phenomenon and reduce the surface pressure fluctuation near the airfoil trailing edge as well as airfoil lift fluctuation. In addition, the turbulent fluctuation at low frequency and the vorticity near the trailing edge are reduced. The vortex spanwise correlation is also decreased near the trailing edge. These factors work jointly and lead to the final airfoil self-noise reduction.
[1] Brooks T F, Pope D S, Marcolini M A. Airfoil self-noise and prediction[M]. Washington, D.C.: NASA, 1989: 1-4.
[2] Sarradj E, Geyer T. Noise generation by porous airfoils, AIAA-2007-3719[R]. Reston: AIAA, 2007.
[3] Herr M, Dobrzynski W. Experimental investigations in low-noise trailing edge design, AIAA-2004-2804[R]. Reston: AIAA, 2004.
[4] Herr M. Design criteria for low-noise trailing-edges, AIAA-2007-3470[R]. Reston: AIAA, 2007.
[5] Finez1 A, Jondeau E, Roger M. Broadband noise reduction with trailing edge brushes, AIAA-2010-3980[R]. Reston: AIAA, 2010.
[6] Howe M S. Aerodynamic noise of a serrated trailing edge[J]. Journal of Fluid and Structures, 1991, 5(1): 33-45.
[7] Howe M S. Noise produced by a sawtooth trailing edge[J]. The Journal of the Acoustical Society of America, 1991, 90(1): 482-487.
[8] Oerlemans S, Fisher M, Maeder T, et al. Reduction of wind turbine noise using optimized airfoils and trailing-edge serrations, AIAA-2008-2819[R]. Reston: AIAA,2008.
[9] Gruber M, Azarpeyvand M, Joseph P F. Airfoil trailing edge noise reduction by the introduction of sawtooth and slitted trailing edge geometries[C]//Proceedings of 20th International Congress on Acoustics. New York: Acoustical Society of America, 2010: 23-27.
[10] Gruber M, Joseph P F, Chong T P. Experimental investigation of airfoil self noise and turbulent wake reduction by the use of trailing edge serrations, AIAA-2010-3803[R]. Reston: AIAA, 2010.
[11] Gruber M, Joseph P F, Chong T P.On the mechanisms of serrated airfoil trailing edge noise reduction, AIAA-2011-2781[R]. Reston: AIAA, 2011.
[12] Gruber M, Joseph P F, Azarpeyvand M. An experimental investigation of novel trailing edge geometries on airfoil trailing edge noise reduction, AIAA-2013-2011[R]. Reston: AIAA, 2013.
[13] Gruber M. Airfoil noise reduction by edge treatments[D]. Southampton: University of Southampton, 2012.
[14] Moreau D J, Brooks L A, Doolan C J. On the noise reduction mechanism of a plate serrated trailing edge at low-to-moderate Reynolds number, AIAA-2012-2186[R]. Reston: AIAA, 2012.
[15] Moreau D J, Doolan C J. Tonal noise from trailing edge serrations at low reynolds number, AIAA-2013-2010[R]. Reston: AIAA, 2013.
[16] Chong T P, Joseph P. An experimental study of tonal noise mechanism of laminar sirfoils, AIAA-2009-3345[R]. Reston: AIAA, 2009.
[17] Chong T P, Joseph P, Gruber M. An experimental study of airfoil instability noise with trailing edge serrations, AIAA-2010-3723[R]. Reston: AIAA, 2010.
[18] Chong T P, Joseph F, Gruber M. On the airfoil self-noise reduction by trailing edge serrations of non-insertion type, AIAA-2012-2185[R]. Reston: AIAA, 2012.
[19] Finez A, Jondeau E, Roger M, et al. Broadband noise reduction of a linear cascade with trailing edge serrations, AIAA-2011-2874[R]. Reston: AIAA, 2011.
[20] Shan Y, Zhang J Z, Shao W R, et al. Experimental and numerical research on jet noise suppression with chevron nozzle for turbofan engines[J]. Acta Aeronautica et Astronautica Sinica, 2013, 34(5): 1046-1056 ( in Chinese). 单勇, 张靖周, 邵万仁, 等. 冠状喷口抑制涡扇发动机喷流噪声试验和数值研究[J]. 航空学报, 2013, 34(5): 1046-1056.
[21] Wagner C, Huttl T, Sagaut P. Large-eddy simulation for acoustics[M]. Cambridge: Cambridge University Press, 2007: 105-109.
[22] Boudet J, Grosjean N, Jacob M C. Wake-airfoil interaction as broadband noise source: A large-eddy simulation study[J]. International Journal of Aeroacoustics, 2005, 4(1): 99-115.
[23] Winkler J, Moreau S, Carolus T. Large-eddy simulation and trailing-edge noise prediction of an airfoil with boundary-layer tripping, AIAA-2009-3197[R]. Reston: AIAA,2009.
[24] Lockard D P. A comparison of Ffowcs Williams-Hawkings solvers for airframe noise applications, AIAA-2002-2580[R]. Reston: AIAA, 2002.
[25] Casalino D, Jacob M, Roger M. Prediction of rod-airfoil interaction noise using the Ffowcs-Williams-Hawkings analogy[J]. AIAA Journal, 2003, 41(2): 182-191.
[26] Chong T P, Vathylakis A, Joseph P, et al. On the noise and wake flow of an airfoil with broken and serrated trailing edges, AIAA-2011-2860[R]. Reston: AIAA, 2011.
[27] Qiao W Y. Aeroacoustics for areoengine[M]. Beijing: Beihang University Press, 2010: 62-64 (in Chiense). 乔渭阳. 航空发动机气动声学[M].北京: 北京航空航天大学出版社, 2010: 62-64.
[28] Hansen C H. Fundamental of acoustics[EB/OL]. (2013-11-10)[2014-11-07].http://www.who.int/occupational_health/publications/noise1.pdf.
[29] Amiet R. Noise due to turbulent flow past a trailing edge[J]. Journal of Sound and Vibration, 1976, 47(3): 387-393.
[30] Sun X F, Zhou S. Aeroacoustics[M]. Beijing: National Defence Industry Press, 1994: 150-156 (in Chinese). 孙晓峰, 周盛.气动声学[M].北京: 国防工业出版社, 1994: 150-156.
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