Experimental Study of Far-Field Radiated Noise Characteristics for the Leading-Edge Slat of a 30P30N Airfoil
Publication: Journal of Aerospace Engineering
Volume 36, Issue 6
Abstract
To study the far-field aerodynamic noise of the leading-edge slat of a high-lift airfoil configuration, an experimental investigation of the BANC-II/30P30N airfoil model was carried out in the D5 areo-acoustic wind tunnel at Beihang University. A novel Kevlar-walled closed test section design was applied, as a way of upgrading the capabilities of a conventional aerodynamic wind tunnel to include far-field acoustic measurements for larger models at real Reynolds numbers. After the flap was retracted and the slat was deployed to isolate slat noise from other possible sources, the surface pressure distribution and the far-field sound pressure signals under different operating conditions were obtained by varying flow speed and angle of attack. The slat noise spectrum characteristics and the dependence of far-field noise on free stream velocity and airfoil incidence angle were acquired by the fast Fourier transform. The joint time-frequency analysis methods (short-time Fourier transform and continuous Morlet wavelet transform) were employed to process the far-field unsteady acoustic signal to identify the inherent physical mechanisms involved in the generation of multiple low-frequency tonal peaks emerging from the broadband component of the slat noise spectra. Results of the short-time Fourier transform (STFT) and wavelet analysis clearly showed that the dominant acoustic energy of these tonal noise was shared between the primary modes through rapid switching in time. Furthermore, the analysis results also indicated that an amplitude-modulation phenomenon exists in the dominant modes. The joint probability density function method was introduced to quantify the mode-switching phenomenon, and the results provided strong evidence that mode-switching occurs between the dominant modes of these low-frequency tones.
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Data Availability Statement
Some or all data, models, or code that support the findings of this study are available from the corresponding author upon reasonable request.
Acknowledgments
This work was supported by the Fundamental Research Funds for the Central Universities and the National Natural Science Foundation of China (Grant Nos. 12072016, 11772033, 1217021666, and 11721202).
References
Amaral, F. R. D., F. H. T. Himeno, C. D. C. Pagani, and M. A. F. de Medeiros. 2017. “Slat noise from an MD30P30N airfoil at extreme angles of attack.” AIAA J. 56 (3): 964–978. https://doi.org/10.2514/1.J056113.
Casalino, D., F. Diozzi, R. Sannino, and A. Paonessa. 2008. “Aircraft noise reduction technologies: A bibliographic review.” Aerosp. Sci. Technol. 12 (1): 1–17. https://doi.org/10.1016/j.ast.2007.10.004.
Choudhari, M., D. P. Lockard, M. G. Macaraeg, B. A. Singer, C. L. Streett, G. R. Neubert, R. W. Stoker, J. R. Underbrink, M. E. Berkman, and M. R. Khorrami. 2002. Aeroacoustic experiments in the Langley low-turbulence pressure tunnel. Washington, DC: National Aeronautics and Space Administration.
Choudhari, M. M., and M. R. Khorrami. 2007. “Effect of three-dimensional shear-layer structures on slat cove unsteadiness.” AIAA J. 45 (Jun): 2174–2186. https://doi.org/10.2514/1.24812.
Deck, S., and R. Laraufie. 2013. “Numerical investigation of the flow dynamics past a three-element aerofoil.” J. Fluid Mech. 732 (Oct): 401–444. https://doi.org/10.1017/jfm.2013.363.
Devenport, W. J., R. A. Burdisso, A. Borgoltz, P. A. Ravetta, M. F. Barone, K. A. Brown, and M. A. Morton. 2013. “The Kevlar-walled anechoic wind tunnel.” J. Sound Vib. 332 (Aug): 3971–3991. https://doi.org/10.1016/j.jsv.2013.02.043.
Dobrzynski, W. 2010. “Almost 40 years of airframe noise research: What did we achieve?” J. Aircr. 47 (2): 353–367. https://doi.org/10.2514/1.44457.
Dobrzynski, W., and M. Pott-Pollenske. 2001. “Slat noise source studies for farfield noise prediction.” In Proc., 7th AIAA/CEAS Aeroacoustics Conf. and Exhibit. Reston, VA: American Institute of Aeronautics and Astronautics.
Guo, Y. 2012. “Slat noise modeling and prediction.” J. Sound Vib. 331 (15): 3567–3586. https://doi.org/10.1016/j.jsv.2012.03.016.
Guo, Y. P., and M. C. Joshi. 2003. “Noise characteristics of aircraft high lift systems.” AIAA J. 41 (Feb): 1247–1256. https://doi.org/10.2514/2.2093.
Guo, Y. P., K. J. Yamamoto, and R. W. Stoker. 2003. “Component-based empirical model for high-lift system noise prediction.” J. Aircr. 40 (1): 914–922. https://doi.org/10.2514/2.6867.
Hamdan, M. N., B. A. Jubran, N. H. Shabaneh, and M. Abu-Samak. 1996. “Comparison of various basic wavelets for the analysis of flow-induced vibration of a cylinder in cross flow.” J. Fluids Struct. 10 (Aug): 633–651. https://doi.org/10.1006/jfls.1996.0042.
Hammond, J. K., and P. R. White. 1996. “The analysis of non-stationary signals using time-frequency methods.” J. Sound Vib. 190 (Feb): 419–447. https://doi.org/10.1006/jsvi.1996.0072.
Hubbard, H. H. 1991. Aeroacoustics of flight vehicles: Theory and practice. Washington, DC: NASA.
Imamura, T., H. Ura, Y. Yokokawa, and K. Yamamoto. 2009. “A far-field noise and near-field unsteadiness of a simplified high-lift-configuration model (slat).” In Proc., 47th AIAA Aerospace Sciences Meeting including The New Horizons Forum and Aerospace Exposition. Reston, VA: American Institute of Aeronautics and Astronautics.
Jenkins, L., M. Khorrami, and M. Choudhari. 2004. “Characterization of unsteady flow structures near leading-edge slat: Part I: PIV measurements.” In Proc., 10th AIAA/CEAS Aeroacoustics Conf. Reston, VA: American Institute of Aeronautics and Astronautics.
Jordan, D., R. W. Miksad, and E. J. Powers. 1997. “Implementation of the continuous wavelet transform for digital time series analysis.” Rev. Sci. Instrum. 68 (3): 1484–1494. https://doi.org/10.1063/1.1147636.
Kegerise, M. A., E. F. Spina, S. Garg, and L. N. Cattafesta. 2004. “Mode-switching and nonlinear effects in compressible flow over a cavity.” Phys. Fluids 16 (3): 678–687. https://doi.org/10.1063/1.1643736.
Khorrami, M. R., M. E. Berkman, and M. Choudhari. 2000. “Unsteady flow computations of a slat with a blunt trailing edge.” AIAA J. 38 (11): 2050–2058. https://doi.org/10.2514/2.892.
Khorrami, M. R., B. A. Singer, and M. E. Berkman. 2002. “Time-accurate simulations and acoustic analysis of slat free shear layer.” AIAA J. 40 (7): 1284–1291. https://doi.org/10.2514/2.1817.
Kolb, A., P. Faulhaber, R. Drobietz, and M. Grünewald. 2007. “Aeroacoustic wind tunnel measurements on a 2D high-lift configuration.” In Proc., 13th AIAA/CEAS Aeroacoustics Conf. (28th AIAA Aeroacoustics Conference). Reston, VA: American Institute of Aeronautics and Astronautics.
Li, L., P. Liu, H. Guo, X. Geng, Y. Hou, and J. Wang. 2018. “Aerodynamic and aeroacoustic experimental investigation of 30P30N high-lift configuration.” Appl. Acoust. 132 (Mar): 43–48. https://doi.org/10.1016/j.apacoust.2017.11.002.
Li, L., P. Liu, H. Guo, Y. Hou, X. Geng, and J. Wang. 2017a. “Aeroacoustic measurement of 30P30N high-lift configuration in the test section with Kevlar cloth and perforated plate.” Aerosp. Sci. Technol. 70 (Nov): 590–599. https://doi.org/10.1016/j.ast.2017.08.039.
Li, L., P. Liu, Y. Xing, and H. Guo. 2017b. “Wavelet analysis of the far-field sound pressure signals generated from a high-lift configuration.” AIAA J. 56 (1): 432–437. https://doi.org/10.2514/1.J056160.
Liu, P., Y. Xing, H. Guo, and L. Li. 2017. “Design and performance of a small-scale aeroacoustic wind tunnel.” Appl. Acoust. 116 (Jan): 65–69. https://doi.org/10.1016/j.apacoust.2016.09.014.
Liu, Y., P. Liu, H. Guo, and T. Hu. 2021. “Effect of a variable-bend slat on tones due to the cove’s self-excited oscillation.” J. Aerosp. Eng. 34 (6): 04021077. https://doi.org/10.1061/(ASCE)AS.1943-5525.0001310.
Liu, Y., P. Liu, H. Guo, T. Hu, and J. Zhang. 2023. “Experimental study of far-field aerodynamic noise characteristics of serrated slat.” J. Aerosp. Eng. 36 (1): 04022104. https://doi.org/10.1061/(ASCE)AS.1943-5525.0001509.
Ma, Z., and X. Zhang. 2009. “Numerical investigation of broadband slat noise attenuation with acoustic liner treatment.” AIAA J. 47 (12): 2812–2820. https://doi.org/10.2514/1.39883.
Mendoza, J., T. Brooks, and W. Humphreys. 2002. “Aeroacoustic measurements of a wing/slat model.” In Proc., 8th AIAA/CEAS Aeroacoustics Conf. & Exhibit. Reston, VA: American Institute of Aeronautics and Astronautics.
Murayama, M., K. Nakakita, K. Yamamoto, H. Ura, Y. Ito, and M. M. Choudhari. 2014. “Experimental study on slat noise from 30P30N three-element high-lift airfoil at JAXA hard-wall lowspeed wind tunnel.” In Proc., 20th AIAA/CEAS Aeroacoustics Conf. Reston, VA: American Institute of Aeronautics and Astronautics.
Pagani, C. C., D. S. Souza, and M. A. F. Medeiros. 2016. “Slat noise: Aeroacoustic beamforming in closed-section wind tunnel with numerical comparison.” AIAA J. 54 (7): 2100–2115. https://doi.org/10.2514/1.J054042.
Pagani, C. C., D. S. Souza, and M. A. F. Medeiros. 2017. “Experimental investigation on the effect of slat geometrical configurations on aerodynamic noise.” J. Sound Vib. 394 (Apr): 256–279. https://doi.org/10.1016/j.jsv.2017.01.013.
Pascioni, K. A., and L. N. Cattafesta. 2016. “Aeroacoustic measurements of leading-edge slat noise.” In Proc., 22nd AIAA/CEAS Aeroacoustics Conf. Reston, VA: American Institute of Aeronautics and Astronautics.
Pope, S. B. 1985. “PDF methods for turbulent reactive flows.” Prog. Energy Combust. Sci. 11 (2): 119–192. https://doi.org/10.1016/0360-1285(85)90002-4.
Qian, S., and D. Chen. 1999. “Joint time–frequency analysis.” IEEE Signal Process. Mag. IEEE 16 (2): 52–67. https://doi.org/10.1109/79.752051.
Roger, M., and S. Perennes. 2000. “Low-frequency noise sources in two-dimensional high-lift devices.” In Proc., 6th Aeroacoustics Conf. and Exhibit. Reston, VA: American Institute of Aeronautics and Astronautics.
Rossiter, J. E. 1964. Wind tunnel experiments on the flow over rectangular cavities at subsonic and transonic speeds. London: Royal Aircraft Establishment.
Singer, B. A., D. P. Lockard, and K. S. Brentner. 2000. “Computational aeroacoustic analysis of slat trailing-edge flow.” AIAA J. 38 (9): 1558–1564. https://doi.org/10.2514/2.1177.
Souza, D. S., D. Rodríguez, L. G. C. Simões, and M. A. F. Medeiros. 2015. “Effect of an excrescence in the slat cove: Flow-field, acoustic radiation and coherent structures.” Aerosp. Sci. Technol. 44 (Jul–Aug): 108–115. https://doi.org/10.1016/j.ast.2015.01.016.
Terracol, M., E. Manoha, and B. Lemoine. 2016. “Investigation of the unsteady flow and noise generation in a slat cove.” AIAA J. 54 (2): 469–489. https://doi.org/10.2514/1.J053479.
Torrence, C., and G. P. Compo. 1998. “A practical guide to wavelet analysis.” Bull. Am. Meteorol. Soc. 79 (5): 61–78. https://doi.org/10.1175/1520-0477(1998)079%3C0061:APGTWA%3E2.0.CO;2.
Ulbrich, N., and R. F. Steinle. 1995. “Semispan model wall interference prediction based on the wall signature method.” In Proc., 33rd Aerospace Sciences Meeting and Exhibit. Reston, VA: American Institute of Aeronautics and Astronautics.
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Published In
Journal of Aerospace Engineering
Volume 36 • Issue 6 • November 2023
Copyright
© 2023 American Society of Civil Engineers.
History
Received: Oct 8, 2022
Accepted: May 12, 2023
Published online: Aug 2, 2023
Published in print: Nov 1, 2023
Discussion open until: Jan 2, 2024
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