Experimental Study of Aerodynamic Behavior of NACA0012 Airfoil near the Surface

Document Type : Research Article

Authors

Malek Ashtar University of Technology, Tehran, Iran

Abstract

When a flying vehicle approaches a surface of water or land, changes occur in the pattern of the fluid flow field around it. This change in flow field eliminates the direct effect on aerodynamics and control of the vehicle. This is more common when the vehicle is landing and taking off, as well as flying at low altitudes, which is called the surface effect. In this research, the phenomenon of surface effect and its effect on aerodynamic coefficients and flow pattern around NACA0012 airfoil in the static incompressible subsonic regime have been investigated numerically and experimentally. Experimental tests were performed in the incompressible subsonic wind tunnel of the Ghadr National Aerodynamics Research Center of Imam Hossein University with a cross-sectional area of 80 by 100 cm. The simulation of the phenomenon is a fixed ground with the minimum possible thickness of the boundary layer in the wind tunnel. Solve the flow field numerically based on Navier Stokes equations along with the Transition-SST viscous model. The impact of the surface effect phenomenon on the change of aerodynamic coefficients has been investigated by considering different distances from the surface in the static state. The pressure distribution on the airfoil surface is measured by an accurate pressure sensor and is due to the surface effect phenomenon at close distances to the surface. The results of the static analysis show an increase in lift force and a decrease in drag force.

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[1] H. Liang, L. Zhou, Z. Zong, L. Sun, An analytical investigation of two-dimensional and three-dimensional biplanes operating in the vicinity of a free surface, Journal of Marine Science and Technology, 18(1) (2013) 12-31.
[2] H. Lu, K.B. Lua, T.T. Lim, K.S. Yeo, Aerodynamics of a two-dimensional hovering wing in ground effect, in:  17th Int. Symp. on Applications of Laser Techniques to Fluid Mechanics, 2014.
[3] M. Holloran, S. O'Meara, Wing in ground effect craft review, DEFENCE SCIENCE AND TECHNOLOGY ORGANISATION CANBERRA (AUSTRALIA), 1999.
[4] Y. He, Shape Optimization of Airfoils Without and With Ground Effect Using a Multi-Objective Genetic Algorithm,  (2014).
[5] H. Winarto, I. Amin, N. Sultan, B. Kidane, O.M. Demircan, A.S. Altinok, K. Çetin, An investigation into wing in ground effect airfoil geometry, RTO SCI Symposium on Challenges in Dynamics, System Identification, Control and Handling Qualities for Land, Air, Sea and Space Vehicles, Berlin, Germany, (2002).
[6] T. Barber, Aerodynamic ground effect: A case study of the integration of CFD and experiments, International Journal of Vehicle Design, 40(4) (2006) 299-316.
[7] M.R. Ahmed, Flow over thick airfoils in ground effect-an investigation on the influence of camber, in:  Proceedings of the 24th Congress of International Council of the Aeronautical Sciences, 2004, pp. 1-11.
[8] X. Zhang, J. Zerihan, Aerodynamics of a double-element wing in ground effect, AIAA journal, 41(6) (2003) 1007-1016.
[9] E. Smuts, A. Sayers, CFD Study of a wing in close proximity to a flat and wavy ground plane, R & D Journal of the South African Institution of Mechanical Engineering, 27 (2011) 1-9.
[10] M. Tahani, A. Bargestan, M.H. Sabour, Numerical investigation of influence geometry variation on the aerodynamic characteristics and static stability of Wing In Ground Effect, Journal of Solid and Fluid Mechanics, 4(2) (2014) 75-87. (in Persian)
[11] T. Ahmed, M.T. Amin, S.R. Islam, S. Ahmed, Computational study of flow around a NACA 0012 wing flapped at different flap angles with varying Mach numbers, Global Journal of Research In Engineering,  (2014).
[12] A.E. Ockfen, K.I. Matveev, Numerical study of wing aerodynamics in ground proximity, in:  ASME International Mechanical Engineering Congress and Exposition, 2008, pp. 97-103.