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Noise Prediction of Ducted Fan Unmanned Aerial Vehicles considering Strut Effect in Hover

  • Park, Minjun (Department of Aerospace Engineering, Korea Advanced Institute of Science and Technology) ;
  • Jang, Jisung (The 3rd Aero Systems Division, Agency for Defense Development) ;
  • Lee, Duckjoo (Department of Aerospace Engineering, Korea Advanced Institute of Science and Technology)
  • Received : 2015.11.24
  • Accepted : 2016.09.07
  • Published : 2017.03.30

Abstract

In recent years, unmanned aerial vehicles (UAVs) have been developed and studied for various applications, including drone deliveries, broadcasting, scouting, crop dusting, and firefighting. To enable the wide use of UAVs, their exact aeroacoustic characteristics must be assessed. In this study, a noise prediction method for a ducted fan UAV with complicated geometry was developed. In general, calculation efficiency is increased by simulating a ducted fan UAV without the struts that fix the fuselage to the ducts. However, numerical predictions of noise and aerodynamics differ according to whether struts are present. In terms of aerodynamic performance, the total thrust with and without struts is similar owing to the tendency of the thrust of a blade to offset the drag of the struts. However, in aeroacoustic simulations, the strut effect should be considered in order to predict the UAV's noise because noise from the blades can be changed by the strut effect. Modelling of the strut effect revealed that the dominant tonal noises were closely correlated with the blade passage frequency of the experimental results. Based on the successful detection of noise sources from a ducted fan UAV system, using the proposed noise contribution contour, methods for noise reduction can be suggested by comparing numerical results with measured noise profiles.

Acknowledgement

Supported by : ADD (Agency for Defense Development), NRF (National Research Foundation of Korea)

References

  1. Leishman, J. G., Principles of Helicopter Aerodynamics, Cambridge University Press, New York, NY, 2000, Chapter 6.
  2. Martin, P. and Tung C., "Performance and Flow Field Measurements on a 10-inch Ducted Rotor VTOL UAV", Proceedings of 60th AHS Annual Forum, 2004.
  3. Fleming, T., Jones, T. and Lusardi, J., "Improved Control of Ducted Fan VTOL UAVs in Crosswind Turbulence", Proceedings of 4th AHS Decennial Specialist's Conference, 2004.
  4. Akturk, A. and Camci, C., "Tip Clearance Investigation of a Ducted Fan Used in VTOL UAVs, Part 1: Baseline Experiments and Computational Validation", Proceedings of ASME Turbo Expo Turbine Technical Conference, IGTI 2011, Vancouver, Canada, June 6-10, 2011.
  5. Akturk, A., Shavalikul, A. and Camci, C, "PIV Measurements and Computational Study of a 5-Inch Ducted Fan for V/STOL UAV Applications", Proceedings of 47th AIAA Aerospace Sciences Meeting and Exhibit, 2009.
  6. Graf, W., Fleming, J. and Ng, N., "Improving Ducted Fan UAV Aerodynamics in Forward Flight", Proceedings of 46th AIAA Aerospace Sciences Meeting and Exhibit, 2008.
  7. Grondin, G., Thipyopas, C. and Moschetta, J. M., "Aerodynamic Analysis of a Multi-Mission Short-Shrouded Coaxial UAV: Part III-CFD for Hovering Flight", In 28th AIAA Applied Aerodynamics Conference, 2010.
  8. Akturk, A. and Cengiz C., "Tip Clearance Investigation of a Ducted Fan Used in VTOL UAVS: Part 1-Baseline Experiments and Computational Validation", ASME 2011 Turbo Expo: Turbine Technical Conference and Exposition, American Society of Mechanical Engineers, 2011.
  9. Akturk, A. and Cengiz C., "Tip Clearance Investigation of a Ducted Fan Used in VTOL UAVS: Part 2-Novel Treatments via Computational Design and Their Experimental Verification", ASME 2011 Turbo Expo: Turbine Technical Conference and Exposition, American Society of Mechanical Engineers, 2011.
  10. Quackenbush, T. R., Wachspress, D. A., Boschitsch, A. H. and Solomon, C. L., "Aeromechanical Analysis Tools for Design and Simulation of VTOL UAV Systems", Proceedings of 60th AHS Annual Forum, 2004.
  11. Maskell, E. C., "A Theory of the Blockage Effects on Bluff Bodies and Stalled Wings in a Closed Wind Tunnel", Aeronautical Research Council London (United Kingdom), 1963.
  12. Morfey, C. L., "Rotating Blades and Aerodynamic Sound", Journal of Sound and Vibration, Vol. 28, No. 3, 1973, 587IN8607-606617.
  13. Duncan, P. E. and Dawson, B., "Reduction of Interaction Tones from Axial Flow Fans by Suitable Design of Rotor Configuration", Journal of Sound and Vibration, Vol. 33, No. 2, 1974, pp. 143-154. https://doi.org/10.1016/S0022-460X(74)80102-1
  14. Longhouse, R. E., "Control of Tip-Vortex Noise of Axial Flow Fans by Rotating Shrouds", Journal of Sound and Vibration, Vol. 58, No. 2, 1978, pp. 201-214. https://doi.org/10.1016/S0022-460X(78)80075-3
  15. Fukano, T., Takamatsu, Y. and Kodama, Y., "The Effects of Tip Clearance on the Noise of Low Pressure Axial and Mixed Flow Fans", Journal of Sound and Vibration, Vol. 105, No. 2, 1986, pp. 291-308. https://doi.org/10.1016/0022-460X(86)90158-6
  16. Fukano, T., Kodama, Y. and Takamatsu, Y., "Noise Generated by Low Pressure Axial Flow Fans, iii: Effects of Rotational Frequency, Blade Thickness and Outer Blade Profile", Journal of Sound and Vibration, Vol. 56, No. 2, 1978, pp. 261-277. https://doi.org/10.1016/S0022-460X(78)80020-0
  17. Jung, W., Song, S., Park, R. M. and Lee, D., "The Noise Prediction of Automotive Axial Fan with Different Blade Sweep Angle Using Unsteady CFD Analysis", Proceedings of Fan 2015 International Conference, 2015.
  18. Arenas, J. P. and Malcolm, J. C., "Recent Trends in Porous sound-Absorbing Materials", Sound and Vibration, Vol. 44, No. 7, 2010, pp. 12-18.
  19. Motsinger, R. Duct Wall Acoustic Treatment, U.S. Patent No 3,819,009, 1974.
  20. Neise W., "Fan Noise-Generation Mechanisms and Control Methods", Proceedings of INTER-NOISE and NOISECON Congress and Conference, 1988.
  21. Lowson, M. V. and Ollerhead, J. B., "A Theoretical Study of Helicopter Rotor Noise", Journal of Sound and Vibration, Vol. 9, No. 2, 1969, pp. 197-222. https://doi.org/10.1016/0022-460X(69)90028-5
  22. Wilcox, D. C., Turbulence Modeling for CFD, Vol. 2. La Canada, CA: DCW industries, 1998.