Aerodynamic Characteristics of a Swept Wing in Close Ground Proximity at High Subsonic Mach Numbers
Publication: Journal of Aerospace Engineering
Volume 25, Issue 4
Abstract
The potential positive influence of close ground proximity on the aerodynamic performance of a wing has long been established; however, flight at a Mach number that causes shock waves to form between the wing and the ground plane would have significant aerodynamic consequences. A numerical study to investigate the effects of extremely low-level flight at subsonic Mach numbers up to 0.9 was conducted involving the symmetric, swept ONERA M6 wing. The aerodynamic coefficients as well as the pressure distributions and tip vortex behavior were analyzed for cases involving the angle of incidence, ground clearance, and Mach number as variables. It was found that lift was augmented with decreasing ground clearance in the majority of cases with the wing at positive incidence, although the critical Mach number for the wing, and in particular for the lower surface, was reduced at very low clearances. The earlier emergence of a lower shock was accompanied by a considerable increase in drag, although this was offset in part by a marked decrease in the strength of the tip vortex when the wing was within one chord length of the ground plane. As a result of the more pronounced shock structures and separation regions that occur above a freestream Mach number of 0.8, there is no net aerodynamic efficiency to be gained from flight with this wing in close ground proximity compared with unbounded flight at altitude.
Get full access to this article
View all available purchase options and get full access to this article.
References
Barber, T. J., Leonardi, E., and Archer, R. D. (2002). “Causes for discrepancies in ground effect analyses.” Aeronaut. J., 106(1066), 653–657.
Dragos, L. (1990). “Numerical solutions of the equation for a thin airfoil in ground effect.” AIAA J., 28(12), 2132–2134.
Dragos, L., and Dinu, A. (1995). “A direct boundary integral equations method to subsonic flow with circulation past thin airfoils in ground effect.” Comput. Methods Appl. Mech. Eng., 121(1-4), 163–176.
Fluent. (2006). Fluent 6.3 user’s guide, Vol. 2, Fluent, Inc., Lebanon, NH.
Langlois, M., Masson, C., and Paraschivoiu, I. (1998). “Fully three-dimensional transition prediction on swept wings in transonic flows.” J. Aircr., 35(2), 254–259.
Maskalik, A. I., and Rozhdestvensky, K. V. (1998). “A view of the present state of research in aero-and hydrodynamics of ekranoplans.” Proc., RTO AVT Symp. on Fluid Dynamics Problems of Vehicles Operating near or in the Air-Sea Interface, Research and Technology Organization, Neuilly-sur-Seine, France.
Menter, F. R. (1994). “Two-equation eddy-viscosity turbulence models for engineering applications.” AIAA J., 32(8), 1598–1605.
Powell, J., Maise, G., Paniagua, J., and Rather, J. (2008). “Maglev launch and the next race to space.” Proc., IEEE Aerospace Conf., IEEE, Big Sky, MT.
Raymond, A. (1921). “Ground influence on aerofoils.” NACA TN-67, National Advisory Committee for Aeronautics, Washington, DC.
Rozhdestvensky, K. V. (2000). Aerodynamics of a lifting system in extreme ground effect, 1st Ed., Springer, New York.
Rozhdestvensky, K. V. (2006). “Wing-in-ground effect vehicles.” Prog. Aerosp. Sci., 42(3), 211–283.
Schetz, J. A. (2001). “Aerodynamics of high speed trains.” Annu. Rev. Fluid Mech., 33, 371–414.
Schmitt, V., and Charpin, F. (1979). “Pressure distributions on the ONERA-M6-Wing at transonic mach numbers. Experimental data base for computer program assessment.” Rep. AGARD AR 138, NATO Science and Technology Organization, Neuilly-sur-Seine, France.
Spalart, P., and Allmaras, S. (1992). “A one-equation turbulence model for aerodynamic flows.” 30th Aerospace Sciences Meeting and Exhibit, AIAA, Reno, NV.
Steinbach, D., and Jacob, K. (1991). “Some aerodynamic aspects of wings near ground.” Trans. Jpn. Soc. Aeronaut. Space Sci., 34(104), 56–70.
Sutherland, W. (1893). “The viscosity of gases and molecular force.” Philos. Mag., 5(36), 507–531.
Weiselsberger, C. (1922). “Wing resistance near the ground.” NACA TM-77, National Advisory Committee for Aeronautics, Washington, DC.
Information & Authors
Information
Published In
Copyright
© 2012 American Society of Civil Engineers.
History
Received: Mar 2, 2011
Accepted: Sep 30, 2011
Published ahead of production: Oct 4, 2011
Published online: Sep 14, 2012
Published in print: Oct 1, 2012
Authors
Metrics & Citations
Metrics
Citations
Download citation
If you have the appropriate software installed, you can download article citation data to the citation manager of your choice. Simply select your manager software from the list below and click Download.