Abstract
This study considers the effect of kinematics on the aerodynamic loads and flow structure around moving blades of micro air vehicles (MAVs) in deep dynamic stall. The transversal (pure heaving) and rotational (pure pitching) motions are considered distinctly to investigate the dynamic stall. An equivalent effective angle of the attack profile is given to both motions. This method helps to figure out the influence of kinematics on flow structures when all boundary conditions and effective angles of attack profiles are the same. An experiment is conducted in fully turbulent flow at Re = 1.5×104 to avoid any transition regime in the boundary layer, and make the results relatively independent of the flow characteristics. A NACA 0012 airfoil is chosen at high reduced frequencies (k = 0.25 and 0.375) and high angles of attack to reach deep dynamic stall conditions. Additionally, time-resolved particle image velocimetry (PIV) and post-processing are used to compute the aerodynamic loads using a control-volume approach. The flow field is also reconstructed using proper orthogonal decomposition (POD) to separate the flow structures in different modes. It is shown that the kinematics can significantly influence the flow structure and aerodynamic loads. In the pre-stall region, the pure pitching motion usually produces higher lift force, while the pure heaving motion has a higher lift peak. However, in the post-stall region, the pure heaving motion usually has higher lift than the pure pitching motion. The pure heaving motion produced lower drag force than the pure pitching motion. For pure heaving motion, the POD analysis reveals there is a high-energy mode in the flow structure that helps to make the vortices more stable compared to pure pitching motion. Furthermore, the pure heaving motion adds extra kinetic energy to the boundary layer, which decelerates the reversal flow and the transfer of the separation point on suction side of the airfoil.
Article PDF
Similar content being viewed by others
Avoid common mistakes on your manuscript.
References
Y. Kim and Z.-T. Xie, Modelling the effect of freestream turbulence on dynamic stall of wind turbine blades, Computers & Fluids, 129 (2016) 53–66.
J. M. Yu, T. S. Leu and J. J. Miau, Investigation of reduced frequency and freestream turbulence effects on dynamic stall of a pitching airfoil, Journal of Visualization, 20 (2017) 31–44.
L. Siegel, K. Ehrenfried, C. Wagner, K. Mullenners and A. Henning, Cross-correlation analysis of synchronized PIV and microphone measurements of an oscillating airfoil, Journal of Visualization, 21 (2018) 381–395.
K. Gharali and D. A. Johnson, Effects of nonuniform incident velocity on a dynamic wind turbine airfoil, Wind Energy, 18 (2015) 237–251.
H. R. Karbasian, J. A. Esfahani and E. Barati, Effect of acceleration on dynamic stall of airfoil in unsteady operating conditions, Wind Energy, 19 (2016) 17–33.
H. Hirano et al., Smoke-wire flow visualization of the dynamic stall vortex over the basic wing-body model in pitching motion, Journal of Visualization, 3 (2001) 311.
M. R. Amiralaei, H. Alighanbari and S. M. Hashemi, Flow field characteristics study of a flapping airfoil using computational fluid dynamics, Journal of Fluids and Structures, 27 (2011) 1068–1085.
P. Gerontakos and T. Lee, PIV study of flow around unsteady airfoil with dynamic trailing-edge flap deflection, Experiments in Fluids, 45 (2008) 955.
K. Gharali and D. A. Johnson, Dynamic stall simulation of a pitching airfoil under unsteady freestream velocity, Journal of Fluids and Structures, 42 (2013) 228–244.
H. R. Karbasian and K. C. Kim, Numerical investigations on flow structure and behavior of vortices in the dynamic stall of an oscillating pitching hydrofoil, Ocean Engineering, 127 (2016) 200–211.
T. Lee and P. Gerontakos, Investigation of flow over an oscillating airfoil, Journal of Fluid Mechanics, 512 (2004) 313–341.
M. Masdari, M. Seyednia and A. Tabrizian, An experimental loading study of a pitching wind turbine airfoil in near- and poststall regions, Journal of Mechanical Science and Technology, 32(8) (2018) 3699–3706.
W. J. McCroskey, Unsteady airfoils, Annual Review of Fluid Mechanics, 14 (1982) 285–311.
M. N. Sefiddashti, M. Nili-Ahmadabadi and B. S. Rizi, Experimental study of effects of circular-cross-section riblets on the aerodynamic performance of Risø airfoil at transient flow regime, Journal of Mechanical Science and Technology, 32(2) (2018) 709–716.
M. M. Koochesfahani, Vortical patterns in the wake of an oscillating airfoil, AIAA Journal, 27 (1989) 1200–1205.
K. D. Jones, C. M. Dohring and M. F. Platzer, Experimental and computational investigation of the Knoller-Betz effect, AIAA Journal, 36 (1998) 1240–1246.
J. Young and J. C. S. Lai, Oscillation frequency and amplitude effects on the wake of a plunging airfoil, AIAA Journal, 42 (2004) 2042–2052.
J. Zhu and J. Zhang, Power extraction performance of two semi-active flapping airfoils at biplane configuration, Journal of Mechanical Science and Technology, 34(1) (2020) 175–187.
J. M. Anderson, K. Streitlien, D. S. Barrett and M. S. Triantafyllou, Oscillating foils of high propulsive efficiency, Journal of Fluid Mechanics, 360 (1998) 41–72.
M. A. Ashraf, J. Young and J. C. S. Lai, Reynolds number, thickness and camber effects on flapping airfoil propulsion, Journal of Fluids and Structures, 27 (2011) 145–160.
A. R. Shanmugam and C. H. Sohn, Numerical investigation on thrust production and unsteady mechanisms of three-dimensional oscillating wing, Journal of Mechanical Science and Technology, 33(12) (2019) 5889–5900.
J. A. Esfahani, E. Barati and H. R. Karbasian, Fluid structures of flapping airfoil with elliptical motion trajectory, Computers & Fluids, 108 (2015) 142–55.
Y. Gao, Q. Zhu and L. Wang, Measurement of unsteady transition on a pitching airfoil using dynamic pressure sensors, Journal of Mechanical Science and Technology, 30(10) (2016) 4571–4578.
J. A. Esfahani, H. R. Karbasian and E. Barati, Proposed kinematic model for fish-like swimming with two pitch motions, Ocean Engineering, 104 (2015) 319–328.
A. R. Shanmugam and C. H. Sohn, Numerical investigation of the aerodynamic benefits of wing-wing interactions in a dragonfly-like flapping wing, Journal of Mechanical Science and Technology, 33(6) (2019) 2725–2735.
D. A. Read, F. S. Hover and M. S. Triantafyllou, Forces on oscillating foils for propulsion and maneuvering, Journal of Fluids and Structures, 17 (2003) 163–183.
G. Cao et al., Nonlinear dynamic response of cable-suspended systems under swinging and heaving motion, Journal of Mechanical Science and Technology, 31(7) (2017) 3157–3170.
H. R. Karbasian, J. A. Esfahani and E. Barati, The power extraction by flapping foil hydrokinetic turbine in swing arm mode, Renewable Energy, 88 (2016) 130–142.
Y. M. Koo et al., Practical payload assessment of a prototype blade for agricultural unmanned rotorcraft, Journal of Mechanical Science and Technology, 32(12) (2018) 5659–5669.
A. Tagliabue, S. Scharnowski and C. J. Kähler, Surface pressure determination: A comparison between PIV-based methods and PSP measurements, Journal of Visualization, 20 (2017) 581–590.
M. Radmanesh, M. Nili-Ahmadabadi, O. Nematollahi and K. C. Kim, Experimental study of square riblets effects on delta wing using smoke visualization and force measurement, Journal of Visualization, 21(3) (2018) 421–432.
B. W. van Oudheusden, F. Scarano, E. W. M. Roosenboom, E. W. F. Casimiri and L. J. Souverein, Evaluation of integral forces and pressure fields from planar velocimetry data for incompressible and compressible flows, Experiments in Fluids, 43 (2007) 153–162.
K. Gharali and D. A. Johnson, PIV-based load investigation in dynamic stall for different reduced frequencies, Experiments in Fluids, 55 (2014) 1803.
S. Wang, D. B. Ingham, L. Ma, M. Pourkashanian and Z. Tao, Turbulence modeling of deep dynamic stall at relatively low Reynolds number, Journal of Fluids and Structures, 33 (2012) 191–209.
T. Durhasan and İ. Karasu, Dye visualization over double delta wing with various kink angles, Journal of Visualization, 22(4) (2019) 669–681.
S. H. Kim and H. D. Kim, Quantitative visualization of the three-dimensional flow structures of a sweeping jet, Journal of Visualization, 22(3) (2019) 437–447.
G. Berkooz, P. Holmes and J. L. Lumley, The proper orthogonal decomposition in the analysis of turbulent flows, Annual Review of Fluid Mechanics, 25 (1993) 539–575.
D. Gil-Prieto, D. G. MacManus, P. K. Zachos, G. Tanguy, F. Wilson and N. Chiereghin, Delayed detached-eddy simulation and particle image velocimetry investigation of S-duct flow distortion, AIAA Journal, 55 (2017) 1893–1908.
J. L. Lumley, Stochastic Tools in Turbulence, New York: Dover (2007).
L. Sirovich, Turbulence and the dynamics of coherent structures, Part 1: Coherent structures, Quarterly of Applied Mathematics, 45 (1987) 561–571.
Acknowledgments
This research was supported by the National High-end Foreign Experts Recruitment Plan of China (No. G20190023036). This study was also supported by the National Research Foundation of Korea (NRF) grant, which is funded by the Korean government (MSIT) (No. 2011-0030013, No. 2018R1A2 B2007117).
Author information
Authors and Affiliations
Corresponding author
Additional information
Recommended by Editor Yang Na
Gul Chang is a Ph.D. student at Pusan National University, Korea. His main research interest is thermo-fluid dynamics in air conditioner and heat exchanger. He is currently working at the R&D Lab. of the Air Solution Division, LG Electronics, Korea.
Hamid Reza Karbasian is a M.Sc. student in School of Mechanical Engineering in Pusan National University. His main research interest is application of fluid mechanics in aerospace and energy conversion systems. He is currently working on flow measurements and flow instabilities in wind energy division.
Shujun Zhang is an Associate Professor of China Aerodynamics Research and Development Center. He received his master and Ph.D. degrees from National University of Defense Technology in 2002 and 2006, respectively. His major research interests are computational aerodynamics, aeroelasticity, and multi-disciplinary integrated design of aircraft.
Yao Yan is an Associate Professor of the School of Aeronautics and Astronautics, University of Electronics Science and Technology of China. He obtained his Ph.D. in Mechanics in 2014 from Tongji University, Shanghai, China. His research interests include regenerative cutting chatter and control for suppression, vibro-impact capsule robot, control of multistability, and exoskeleton robot.
Binqi Chen is a Lecturer of the School of Aeronautics and Astronautics, University of Electronics Science and Technology of China. She obtained her Ph.D. in Aircraft Design in 2016 from Nanjing University of Aeronautics and Astronautics, Nanjing, China. Her research interests include intelligent unmanned aerial vehicle technology and multi-disciplinary optimization of aircraft.
Kyung Chun Kim is a Distinguished Professor at the School of Mechanical Engineering of Pusan National University in Korea. He obtained his Ph.D. from the Korea Advanced Institute of Science and Technology (KAIST), Korea, in 1987. He was selected as a Member of the National Academy of Engineering of Korea in 2004. His research interests include flow measurements based on PIV/LIF, POCT development, wind turbines, and organic Rankine cycle system.
Rights and permissions
About this article
Cite this article
Chang, G., Karbasian, H.R., Zhang, S. et al. The influence of kinematics of blades on the flow structure in deep dynamic stall. J Mech Sci Technol 34, 2855–2868 (2020). https://doi.org/10.1007/s12206-020-0618-1
Received:
Revised:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s12206-020-0618-1