- Volume 16 Issue 1
DOI QR Code
An Experimental Study on the Wake Characteristics of a Quadrotor UAV
쿼드로터형 무인비행체의 후류 특성에 관한 실험적 연구
- Lee, Seungcheol (Department of Mechanical Engineering, Ulsan National Institute of Science and Technology) ;
- Chae, Seokbong (Department of Mechanical Engineering, Ulsan National Institute of Science and Technology) ;
- Kim, Jooha (Department of Mechanical Engineering, Ulsan National Institute of Science and Technology)
- Received : 2018.03.22
- Accepted : 2018.04.03
- Published : 2018.04.30
In the present study, we investigate the flow characteristics of a quadrotor UAV in a hovering mode by measuring multiple two-dimensional velocity fields in the wake. The experiment is conducted at Re = 24,000 in a chamber large enough to neglect the ground effect, where Re is the Reynolds number based on the rotor chord length and the rotor tip speed. The rotational speed of the rotor is determined by an optical tachometer so that the lift force can be balanced with the weight of the UAV. The velocity field measured on the center plane of the rotor shows that the vortices are shedding from the tip of the rotor, inducing large fluctuations in the streamwise velocity along the wake shear layer. The strength of the rotor-tip vortex shedding is asymmetric with respect to the rotor axis due to the interaction between the rotor and the wake centerline of each rotor is inclined to the center of the UAV due to the pressure difference caused by the induced velocity. The wake from each rotor moves closer to each other while traveling in the streamwise direction, and then is merged together inducing large fluctuations in the transverse velocity. Due to the wake merging, on the center plane of the UAV, the velocity increases in the streamwise direction showing two-peak structure in the streamwise velocity contours.
Supported by : 한국연구재단, UNIST
- Otsuka, H., and Nagatani, K., 2016, "Thrust loss saving design of overlapping rotor arrangement on small multirotor unmanned aerial vehicles," In Robotics and Automation (ICRA), 2016 IEEE International Conference on pp. 3242-3248.
- Kim, D. K., Wie, S. Y., Song, J. R., Song, K. W., Hwang, C. J. and Joo, G., 2015, "Technology Trend on the Status of the Unmanned Multicopter Development," Current Industrial and Technological Trends in Aerospace, Vol. 13, No. 2, pp. 80-91.
- Ramasamy, M., Gold, N. P., and Bhagwat, M. J., 2010, "Rotor Hover Performance and Flowfield Measurements with Untwisted and Highly-Twisted Blades," 36th European Rotorcraft Forum.
- Caradonna, F., Henley, E., Silva, M., Huang, S., Komerath, N., Mahalingam, R., Reddy, U., Funk, R., Wong, O., Ames, R., Darden, L., Villareal, L., and Gregory, J., 1999, "Performance Measurement and Wake Characteristics of a Model Rotor in Axial Flight," Journal of the American Helicopter Society, Vol. 44, pp. 101-108. https://doi.org/10.4050/JAHS.44.101
- Conlisk, A. T., 1997, "Modern helicopter aerodynamics," Annual review of fluid mechanics, Vol. 29(1), pp. 515-567. https://doi.org/10.1146/annurev.fluid.29.1.515
- Hoffmann, G., Huang, H., Waslander, S., and Tomlin, C., 2007, "Quadrotor helicopter flight dynamics and control: Theory and experiment," In AIAA Guidance, Navigation and Control Conference and Exhibit, p. 6461.
- Yoon, S., Lee, H. C., and Pulliam, T. H., 2016, "Computational Analysis of Multi-Rotor Flows," In 54th AIAA Aerospace Sciences Meeting, p. 0812.
- Keane, R. D., and Adrian, R. J., 1990, "Optimization of particle image velocimeters. I. Double pulsed systems," Measurement science and technology, 1(11), 1202. https://doi.org/10.1088/0957-0233/1/11/013
- Zhou, W., Ning, Z., Li, H., and Hu, H., 2017, "An Experimental Investigation on Rotor-to-Rotor Interactions of Small UAV Propellers," In 35th AIAA Applied Aerodynamics Conference, p. 3744.