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Alleviation of Propeller-Slipstream-Induced Unsteady Pylon Loading by a Flow-Permeable Leading Edge

Published Online:https://doi.org/10.2514/1.C035250

The impingement of a propeller slipstream on a downstream surface causes unsteady loading, which may lead to vibrations responsible for structure-borne noise. A low-speed wind-tunnel experiment was performed to quantify the potential of a flow-permeable leading edge to alleviate the slipstream-induced unsteady loading. For this purpose, a tractor propeller was installed at the tip of a pylon featuring a replaceable leading-edge insert in the region of slipstream impingement. Tests were carried out with four flow-permeable inserts, with different hole diameters and cavity depths, and a baseline solid insert. Particle-image-velocimetry measurements showed that the flow through the permeable surface caused an increase in boundary-layer thickness on the pylon’s suction side. This led to a local drag increase and reduced lift, especially for angles of attack above 6 deg. Furthermore, it amplified the viscous interaction with the propeller tip-vortex cores, reducing the velocity fluctuations near the pylon surface by up to 35%. Consequently, lower tonal noise emissions from the pylon were measured in the far field. This suggests that the desired reduction in surface pressure fluctuations was achieved by application of the flow-permeable leading edge.

References

  • [1] Guynn M. D., Berton J. J., Haller W. J., Hendricks E. S. and Tong M. T., “Performance and Environmental Assessment of an Advanced Aircraft with Open Rotor Propulsion,” NASA TM-2012-217772, Oct. 2012. Google Scholar

  • [2] Mann S. A. E. and Stuart C. A., “Advanced Propulsion Through the 1990s—An Airframer’s View,” 21st Joint Propulsion Conference, AIAA Paper 1985-1192, July 1985. doi:https://doi.org/10.2514/6.1985-1192 LinkGoogle Scholar

  • [3] Page M. A., Ivey D. M. and Welge H. R., “Ultra High Bypass Engine Applications to Commercial and Military Aircraft,” SAE Aerospace Technology Conference and Exposition, SAE TP  861720, Long Beach, CA, Oct. 1986. doi:https://doi.org/10.4271/861720 CrossrefGoogle Scholar

  • [4] Goldsmith I. M. and Bowles J. V., “Potential Benefits for Propfan Technology on Derivatives of Future Short- to Medium-Range Transport Aircraft,” 16th Joint Propulsion Conference, AIAA Paper 1980-1090, June 1980. doi:https://doi.org/10.2514/6.1980-1090 LinkGoogle Scholar

  • [5] Goldsmith I. M., “A Study to Define the Research and Technology Requirements for Advanced Turbo/Propfan Transport Aircraft,” NASA CR-166138, Feb. 1981. Google Scholar

  • [6] Block P. J. W., “Experimental Study of the Effects of Installation on Single- and Counter-Rotation Propeller Noise,” NASA TP-2541, April 1986. Google Scholar

  • [7] Block P. J. W. and Gentry G. L., “Directivity and Trends of Noise Generated by a Propeller in a Wake,” NASA TP-2609, Sept. 1986. Google Scholar

  • [8] Sinnige T., Ragni D., Malgoezar A. M. N., Eitelberg G. and Veldhuis L. L. M., “APIAN-INF: An Aerodynamic and Aeroacoustic Investigation of Pylon-Interaction Effects for Pusher Propellers,” CEAS Aeronautical Journal, Vol. 9, No. 2, 2018, pp. 291–306. doi:https://doi.org/10.1007/s13272-017-0247-2 CrossrefGoogle Scholar

  • [9] Magliozzi B., Hanson D. B. and Amiet R. K., “Propeller and Propfan Noise,” Aeroacoustics of Flight Vehicles: Theory and Practice, Vol. 1: Noise Sources, edited by Hubbard H. H., NASA Langley Research Center, Hampton, VA, 1992, pp. 1–64. Google Scholar

  • [10] Ljunggren S., Samuelsson L. and Widing K., “Slipstream-Induced Pressure Fluctuations on a Wing Panel,” Journal of Aircraft, Vol. 26, No. 10, 1989, pp. 914–919. doi:https://doi.org/10.2514/3.45861 LinkGoogle Scholar

  • [11] Johnston R. T. and Sullivan J. P., “Unsteady Wing Surface Pressures in the Wake of a Propeller,” Journal of Aircraft, Vol. 30, No. 5, 1993, pp. 644–651. doi:https://doi.org/10.2514/3.46393 LinkGoogle Scholar

  • [12] Sinnige T., de Vries R., Della Corte B., Avallone F., Ragni D., Eitelberg G. and Veldhuis L. L. M., “Unsteady Pylon Loading Caused by Propeller-Slipstream Impingement for Tip-Mounted Propellers,” Journal of Aircraft, Vol. 55, No. 4, 2018, pp. 1605–1618. doi:https://doi.org/10.2514/1.C034696 LinkGoogle Scholar

  • [13] Loeffler I. J., “Structureborne Noise Control in Advanced Turboprop Aircraft,” NASA TM-88947, Jan. 1987. LinkGoogle Scholar

  • [14] van Arnhem N., Sinnige T., Stokkermans T. C. A., Eitelberg G. and Veldhuis L. L. M., “Aerodynamic Interaction Effects of Tip-Mounted Propellers Installed on the Horizontal Tailplane,” 2018 AIAA Aerospace Sciences Meeting, AIAA Paper 2018-2052, Jan. 2018. doi:https://doi.org/10.2514/6.2018-2052 LinkGoogle Scholar

  • [15] Martinez R., “Predictions of Wing and Pylon Forces Caused by Propeller Installation,” NASA CR-178298, May 1987. Google Scholar

  • [16] Unruh J. F., “Aircraft Propeller Induced Structure-Borne Noise,” NASA CR-4255, Oct. 1989. Google Scholar

  • [17] Tinetti A. F., “On the Use of Surface Porosity to Reduce Wake-Stator Interaction Noise,” Ph.D. Thesis, College of Engineering, Virginia Polytechnic Inst. and State Univ., Blacksburg, VA, 2001. Google Scholar

  • [18] Tinetti A. F., Kelly J. J., Bauer S. X. S. and Thomas R. H., “On the Use of Surface Porosity to Reduce Unsteady Lift,” 15th AIAA Computational Fluid Dynamics Conference, AIAA Paper 2001-2921, June 2001. doi:https://doi.org/10.2514/6.2001-2921 LinkGoogle Scholar

  • [19] Tinetti A. F., Kelly J. J., Thomas R. H. and Bauer S. X. S., “Reduction of Wake-Stator Interaction Noise Using Passive Porosity,” 40th AIAA Aerospace Sciences Meeting and Exhibit, AIAA Paper 2002-1036, Jan. 2002. doi:https://doi.org/10.2514/6.2002-1036 LinkGoogle Scholar

  • [20] Lee S., “Reduction of Blade-Vortex Interaction Noise Through Porous Leading Edge,” AIAA Journal, Vol. 32, No. 3, 1994, pp. 480–488. doi:https://doi.org/10.2514/3.12011 AIAJAH 0001-1452 LinkGoogle Scholar

  • [21] Vergara Torralba C., Bilka M. and Schram C., “Experimental and Analytical Study of Tonal Source Attenuation in Wake-Stator Interaction with Porous Material,” 14th International Symposium on Transport Phenomena and Dynamics of Rotating Machinery (ISROMAC-14), Feb. 2012. Google Scholar

  • [22] Raghunathan S., “Passive Control of Shock-Boundary Layer Interaction,” Progress in Aerospace Sciences, Vol. 25, No. 3, 1988, pp. 271–296. doi:https://doi.org/10.1016/0376-0421(88)90002-4 PAESD6 0376-0421 CrossrefGoogle Scholar

  • [23] Roger M., Schram C. and De Santana L., “Reduction of Airfoil Turbulence-Impingement Noise by Means of Leading-Edge Serrations and/or Porous Material,” 19th AIAA/CEAS Aeroacoustics Conference, AIAA Paper 2013-2108, May 2013. doi:https://doi.org/10.2514/6.2013-2108 LinkGoogle Scholar

  • [24] Angland D., Zhang X. and Molin N., “Measurements of Flow Around a Flap Side Edge with Porous Edge Treatment,” AIAA Journal, Vol. 47, No. 7, 2009, pp. 1660–1671. doi:https://doi.org/10.2514/1.39311 AIAJAH 0001-1452 LinkGoogle Scholar

  • [25] Bae Y. and Moon Y. J., “Effect of Passive Porous Surface on the Trailing-Edge Noise,” Physics of Fluids, Vol. 23, No. 12, 2011, Paper 126101. doi:https://doi.org/10.1063/1.3662447 CrossrefGoogle Scholar

  • [26] Geyer T., Sarradj E. and Fritzsche C., “Measurement of the Noise Generation at the Trailing Edge of Porous Airfoils,” Experiments in Fluids, Vol. 48, No. 2, 2010, pp. 291–308. doi:https://doi.org/10.1007/s00348-009-0739-x EXFLDU 0723-4864 CrossrefGoogle Scholar

  • [27] Abbott I. H., Von Doenhoff A. E. and Stivers L. S., “Summary of Airfoil Data,” NACA TR-824, Jan. 1945. Google Scholar

  • [28] Scarano F. and Riethmuller M. L., “Iterative Multigrid Approach in PIV Image Processing with Discrete Window Offset,” Experiments in Fluids, Vol. 26, No. 6, 1999, pp. 513–523. doi:https://doi.org/10.1007/s003480050318 EXFLDU 0723-4864 CrossrefGoogle Scholar

  • [29] Wieneke B., “PIV Uncertainty Quantification from Correlation Statistics,” Measurement Science and Technology, Vol. 26, No. 7, 2015, Paper 074002. doi:https://doi.org/10.1088/0957-0233/26/7/074002 MSTCEP 0957-0233 CrossrefGoogle Scholar

  • [30] van Oudheusden B. W., “PIV-Based Pressure Measurement,” Measurement Science and Technology, Vol. 24, No. 3, 2013, Paper 032001. doi:https://doi.org/10.1088/0957-0233/24/3/032001 MSTCEP 0957-0233 CrossrefGoogle Scholar

  • [31] Ragni D., van Oudheusden B. W. and Scarano F., “3D Pressure Imaging of an Aircraft Propeller Blade-Tip Flow by Phase-Locked Stereoscopic PIV,” Experiments in Fluids, Vol. 52, No. 2, 2012, pp. 463–477. doi:https://doi.org/10.1007/s00348-011-1236-6 EXFLDU 0723-4864 CrossrefGoogle Scholar

  • [32] Ragni D., Simão Ferreira C. and Correale G., “Experimental Investigation of an Optimized Airfoil for Vertical-Axis Wind Turbines,” Wind Energy, Vol. 18, No. 9, 2015, pp. 1629–1643. doi:https://doi.org/10.1002/we.1780 WENTEO CrossrefGoogle Scholar

  • [33] Brandt A., “Statistics and Random Processes,” Noise and Vibration Analysis: Signal Analysis and Experimental Procedures, 2nd ed., Wiley, New York, 2011, pp. 65–71. CrossrefGoogle Scholar

  • [34] Dougherty R. P., “Beamforming In Acoustic Testing,” Aeroacoustic Measurements, edited by Mueller T. J., Springer–Verlag, Berlin, 2002, pp. 62–97. CrossrefGoogle Scholar

  • [35] Sijtsma P., “Phased Array Beamforming Applied to Wind Tunnel and Flyover Tests,” National Aerospace Lab./ NLR TP-2010-549, Amsterdam, Dec. 2010. Google Scholar

  • [36] Arce León C., Merino-Martínez R., Ragni D., Avallone F. and Snellen M., “Boundary Layer Characterization and Acoustic Measurements of Flow-Aligned Trailing Edge Serrations,” Experiments in Fluids, Vol. 57, Dec. 2010, Paper 182. doi:https://doi.org/10.1007/s00348-016-2272-z EXFLDU 0723-4864 Google Scholar

  • [37] Lord Rayleigh F. R. S., “XXXI. Investigations in Optics with Special Reference to the Spectroscope,” London, Edinburgh, and Dublin Philosophical Magazine and Journal of Science, Vol. 8, No. 49, 2009, pp. 261–274. doi:https://doi.org/10.1080/14786447908639684 CrossrefGoogle Scholar

  • [38] Avallone F., Casalino D. and Ragni D., “Impingement of a Propeller-Slipstream on a Leading Edge with a Flow-Permeable Insert: A Computational Aeroacoustic Study,” International Journal of Aeroacoustics, Vol. 17, Nos. 6–8, 2018, pp. 687–711. doi:https://doi.org/10.1177/1475472X18788961 CrossrefGoogle Scholar

  • [39] Mineck R. E. and Hartwich P. M., “Effect of Full-Chord Porosity on Aerodynamic Characteristics of the NACA 0012 Airfoil,” NASA TP-3591, April 1996. Google Scholar

  • [40] Veldhuis L. L. M., “Propeller Wing Aerodynamic Interference,” Ph.D. Thesis, Faculty of Aerospace Engineering, Delft Univ. of Technology, Delft, The Netherlands, 2005. Google Scholar