Skip to main content
Skip to article control options
No AccessRegular Paper

Microphone Array Measurement in European Transonic Wind Tunnel at Flight Reynolds Numbers

Published Online:https://doi.org/10.2514/1.J055262

This paper presents an experimental investigation of small-scale model airframe noise at various Reynolds numbers up to the real flight case. The study consists of data acquired with a microphone array in the European Transonic Wind Tunnel. The advantage of this wind tunnel is to enable testing simultaneously at cryogenic temperatures and increased pressure levels, which extends the range of achievable Reynolds numbers up to those pertaining to full-scale flight conditions. At the DLR, German Aerospace Center, the microphone array measurement technique has been further developed to perform measurements under combined cryogenic and pressurized conditions. For this purpose, a microphone array consisting of 96 microphones was designed and constructed. In this paper, aeroacoustic results are presented for various Reynolds numbers up to the real flight case on an Airbus K3DY half-model of scale 1:13.6. The results showed significant Reynolds number and Mach number dependency for various sources. Of particular note are various dominant sources appearing on the flap at real flight Reynolds numbers. To the author’s knowledge, this is the first time that airframe noise data for a small-scale model have been acquired at real flight Reynolds numbers.

References

  • [1] Stoker R. W., Guo Y. P., Street G. and Burnside N., “Airframe Noise Source Location of a 777 Aircraft in Flight and Comparisons with Past Model Scale Tests,” Ninth AIAA/CEAS Aeroacoustics Conference, AIAA Paper  2003-3232, 2003. LinkGoogle Scholar

  • [2] Hayes J. A., Horne W. C., Jaeger S. M. and Soderman P. T., “Measurement of Reynolds Number Effect on Airframe Noise in the 12-Foot Pressure Wind Tunnel,” Fifth AIAA/CEAS Aeroacoustics Conference and Exhibit, AIAA Paper  1999-1959, 1999. LinkGoogle Scholar

  • [3] Stoker R. W., Gutierrez R., Larssen J. V., Underbrink J. R., Gatlin G. M. and Spells C., “High Reynolds Number Aeroacoustic Testing in NASAs National Transonic Facility (NTF),” 46th AIAA/CEAS Aerospace Science Meeting and Exhibit, AIAA Paper  2008-838, 2008. LinkGoogle Scholar

  • [4] Ahlefeldt T. and Koop L., “Microphone Array Measurements in a Cryogenic Wind Tunnel,” AIAA Journal, Vol. 48, No. 7, 2010, pp. 1470–1479. doi:https://doi.org/10.2514/1.J050083 AIAJAH 0001-1452 LinkGoogle Scholar

  • [5] Ahlefeldt T., “Aeroacoustic Measurements of a Scaled Half-Model at High Reynolds Numbers,” AIAA Journal, Vol. 51, No. 12, 2013, pp. 2783–2791. doi:https://doi.org/10.2514/1.J052345 AIAJAH 0001-1452 LinkGoogle Scholar

  • [6] Ahlefeldt T. and Quest J., “High-Reynolds Number Aeroacoustic Testing Under Pressurised Cryogenic Conditions in PETW,” 50th AIAA Aerospace Sciences Meeting Including the New Horizons Forum and Aerospace Exposition, AIAA Paper  2012-0107, 2012. LinkGoogle Scholar

  • [7] Mueller T., (ed.), “Aeroacoustic Measurements,” Experimental Fluid Mechanics, Springer–Verlag, Berlin, 2002, p. 163. Google Scholar

  • [8] Microphone Handbook. Vol. 1: Theory,” Brüel and Kjær BE 1447 11, Canton, MI, 1996, pp. 2–55ff. Google Scholar

  • [9] Younglove B. A., “Thermophysical Properties of Fluids. I. Argon, Ethylene, Parahydrogen, Nitrogen, Nitrogene Trifluride and Oxygen,” Journal of Physical and Chemical Reference Data, Vol. 11, No. 1, 1982, pp. 169–177. JPCRBU 0047-2689 Google Scholar

  • [10] Product Data, 20 kHz Array Microphone—Type 4958,” Brüel and Kjær, Canton, MI, p. 2, http://www.bksv.jp/doc/bp2173.pdf [accessed 09 June 2016]. Google Scholar

  • [11] Castellini P. and Martarelli M., “Acoustic Beamforming: Analysis of Uncertainty and Metrological Performances,” Mechanical Systems and Signal Processing, Vol. 22, No. 3, 2008, pp. 672–692. doi:https://doi.org/10.1016/j.ymssp.2007.09.017 CrossrefGoogle Scholar

  • [12] Quest J., “ETW—High Quality Test Performance in Cryogenic Environment,” 21st Aerodynamic Measurement Technology and Ground Testing Conference, AIAA Paper  2000-2260, 2000. LinkGoogle Scholar

  • [13] Sitsma P., “CLEAN Based on Spatial Source Coherence,” International Journal of Aeroacoustics, Vol. 6, No. 4, 2007, pp. 357–374. doi:https://doi.org/10.1260/147547207783359459 CrossrefGoogle Scholar

  • [14] Sitsma P., “Experimental Techniques for Identification and Characterisation of Noise Sources,” National Aerospace Lab. NLR Rept.  NLR-TP-2004-165, 2004, pp. 23–24, 34–35, http://reports.nlr.nl:8080/xmlui/bitstream/handle/10921/577/TP-2004-165.pdf?sequence=1. Google Scholar

  • [15] Hilsenrath J., Beckett C. W., Benedict W. S., Fano L., Hodge H. J., Masi J. F., Nuttall R. L., Touloukian Y. S. and Woolley H. W., “Tables of Thermal Properties of Gases,” United States Department of Commerce, National Bureau of Standards Circular  564, Washington, D.C., Nov. 1955, pp. 347–350. Google Scholar

  • [16] Crighton D. G., “Airframe Noise,” Aeroacoustics of Flight Vehicles: Theory and Practice. Volume 1: Noise Sources, NASA Langley Research Center, Hampton, VA, 1991, pp. 391–447. Google Scholar

  • [17] Sodermann P. T., Kafyeke F., Burnside N. J., Chandrasekharan R., Jaeger S. M. and Boudreau J., “Airframe Noise Study of a CRJ-700 Aircraft Model in the NASA Ames 7- by 10-Foot Wind Tunnel No. 1,” Eighth AIAA/CEAS Aeroacoustics Conference and Exhibit, AIAA Paper  2002-2406, 2002. LinkGoogle Scholar

  • [18] Guo Y. P. and Joshi M. C., “Noise Characteristics of Aircraft High Lift Systems,” AIAA Journal, Vol. 41, No. 7, 2003, pp. 1247–1256. doi:https://doi.org/10.2514/2.2093 AIAJAH 0001-1452 LinkGoogle Scholar

  • [19] Dobrzynski W., “Almost 40 Years of Airframe Noise Research: What Did We Achieve?Journal of Aircraft, Vol. 47, No. 2, 2010, pp. 353–367. doi:https://doi.org/10.2514/1.44457 LinkGoogle Scholar

  • [20] Crighton D. G., Dowling A. P., Ffwocs Williams J. E., Heckl M. and Lipperton F. G., Modern Methods in Analytical Acoustics: Lecture Notes, Springer–Verlag, Berlin, 1992, pp. 334–342. CrossrefGoogle Scholar

  • [21] Curle N., “The Influence of Solid Boundaries upon Aerodynamic Sound,” Proceedings of the Royal Society of London, Series A: Mathematical and Physical Sciences, Vol. 231, No. 1187, 1955, pp. 505–514. CrossrefGoogle Scholar

  • [22] Dobrzynski W. and Pott-Polenske M., “Noise Source Studies for Farfield Noise Prediction,” Seventh AIAA/CEAS Aeroacoustics Conference, AIAA Paper  2001-2158, 2001. LinkGoogle Scholar

  • [23] Khorrami M. R., “Understanding Slat Noise Sources,” Proceedings of EUROMECH Colloquium 449, Chamonix, France, Dec. 2003, http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.78.1513&rep=rep1&type=pdf. Google Scholar

  • [24] Kröber S. and Koop L., “Comparison of Microphone Array Measurements of an Airfoil with High-Lift Devices in Open and Closed Wind Tunnels,” Seventh AIAA/CEAS Aeroacoustics Conference, AIAA Paper  2001-2158, 2001. Google Scholar

  • [25] Dobrzynski W., Gehlhar B. and Buchholz H., “Model and Full Scale High-Lift Wing Wind Tunnel Experiments Dedicated to Airframe Noise Reduction,” Aerospace and Technology, Vol. 5, No. 1, 2001, pp. 27–33. doi:https://doi.org/10.1016/S1270-9638(00)01079-8 CrossrefGoogle Scholar