Browse > Article
http://dx.doi.org/10.5139/JKSAS.2019.47.7.469

Study for Aerodynamic and Aeroacoustic Characteristics of Multirotor Configurations Considering the Wake Interaction Effect  

Ko, Jeongwoo (Department of Mechanical and Aerospace Engineering, Seoul National University)
Kim, Dong Wook (Department of Mechanical and Aerospace Engineering, Seoul National University)
Lee, Soogab (Department of Mechanical and Aerospace Engineering, Seoul National University)
Publication Information
Journal of the Korean Society for Aeronautical & Space Sciences / v.47, no.7, 2019 , pp. 469-478 More about this Journal
Abstract
Multirotor configurations such as VTOL and urban air mobility have been focused on today due to the high maneuverability. Aerodynamic and aeroacoustic characteristics of multirotor have much difference to those of a single rotor. In this study, a numerical analysis based on the free wake vortex lattice method is used for identifying the wake interaction effect. In order to compare the various configurations and operating conditions, the effects of the spacing between the rotors in hovering flight and the effects of the advancing ratio and the formation in forward flight are discussed. In the hovering flight, the unsteady loading of multirotor changes periodically and loading fluctuation increases as decreasing the spacing. It causes the variation in unsteady loading noise and the noise directivity pattern. In the forward flight, the difference in loading fluctuation and noise characteristics are observed according to the diamond and square formation of rotors. By comparing with results of single rotor analysis, multirotor configurations have different directivity pattern and amplitude of loading noise according to the location of each rotor. As a result, wake interaction effect becomes a highly important factor for aerodynamic and aeroacoustic analysis according to multirotor configurations and operating conditions.
Keywords
Multirotor; Wake interaction; Unsteady loading noise; Aeroacoustics;
Citations & Related Records
연도 인용수 순위
  • Reference
1 Floreano, D., and Wood, R. J., "Science, technology and the future of small autonomous drones," Nature, Vol. 521, 2015, pp. 460-466.   DOI
2 Shukla, D., and Komerath, N., "Multirotor Drone Aerodynamic Interaction Investigation," Drones, Vol. 2, No. 4, 2018, p. 43.   DOI
3 Tinney, C. E., and Sirohi, J., "Multirotor drone noise at static thrust," AIAA Journal, Vol. 56, No. 7, 2018, pp. 2816-2826.   DOI
4 Casalino, D., van der Velden, W. C. P., and Romani, G., "Community Noise of Urban Air Transportation Vehicles," AIAA Scitech 2019 Forum, January 2019, p. 1834.
5 Lee, H. J., and Lee, D. J., "Computational study of wake interaction in quadcopter unmanned aerial vehicle," 7th Asian/Australian Rotorcraft Forum, October 2018.
6 Ventura Diaz, P., and Yoon, S., "High-fidelity computational aerodynamics of multi-rotor unmanned aerial vehicles," 2018 AIAA Aerospace Sciences Meeting, January 2018, p. 1266.
7 Zhou, W., Ning, Z., Li, H., and Hu, H., "An Experimental Investigation on Rotor-to-Rotor Interactions of Small UAV Propellers," 35th AIAA Applied Aerodynamics Conference, June 2017, p. 3744.
8 Tinney, C. E., and Sirohi, J., "Multirotor Drone Noise at Static Thrust," AIAA Journal, Vol. 56, No. 7, 2018, pp. 2816-2826.   DOI
9 Zawodny, N. S., Christian, A., and Cabell, R., "A Summary of NASA Research Exploring the Acoustics of Small Unmanned Aerial Systems," AHS Specialists' Conference on Aeromechanics Design for Transformative Vertical Flight, January 2018, pp. 1-11.
10 Katz, J., and Plotkin, A., Low-Speed Aerodynamics, 2nd Ed., Cambridge University Press, 2001.
11 Mahendra, J. B., and Leishman, J. G., "Generalized Viscous Vortex Model for Application to Free-Vortex Wake and Aeroacoustic Calculations," Proceedings of the 58th Annual Forum of the American Helicopter Society, June 2002.
12 Farassat, F., "Derivation of formulations 1 and 1a of farassat," NASA TM 2007-214853, 2007.
13 Quackenbush, T. R., Wachspress, D. A., and Boschitsch, A. H., "Rotor Aerodynamic Loads Computation Using a Constant Vorticity Contour Free Wake Model," Journal of Aircraft, Vol. 32, No. 5, 1995, pp. 911-920.   DOI
14 Bliss, D. B., Teske, M. E., and Quackenbush, T. R., "A New Methodology for Free Wake Analysis Using Curved Vortex Elements," NASA CR 3958, 1987.