21st Congress of International Council of the Aeronautical Sciences, Melbourne, Australia, 13-18 September, 1998
Paper ICAS-98-3.8.1

TRAILING-EDGE FLOWS ON HIGHLY-SWEPT WINGS

Shires A.
Defence Evaluation and Research Agency, United Kingdom

Keywords: trailing-edge flow, highly-swept wings

An experimental and theoretical study is described of the flow over a constant-chord wing with a significant amount of rear camber, for three trailing edge sweeps 30°, 40° and 50°. The research is aimed at understanding the nature of complex three-dimensional flows and means of controlling these flows for highly swept wings, necessary for low observable combat aircraft. This paper describes the results from a series of wind-tunnel tests in the 13ft x 9ft low speed wind tunnel at DERA Bedford. Oil flow visualisation and analysis of wing pressure and force coefficients has helped to provide a good understanding of the nature of these flows for a range of tunnel speeds and angles of incidence. Calculations have been made with two computational fluid dynamics (CFD) codes, One a Viscous coupled Full-Potential code (VFP) and the other, the SAUNA system, based On a solution of the Reynolds averaged Navier-Stokes equations. The former provides pressure distributions in good agreement with measurement, except for flows with regions of separation. The SAUNA system, using a k-omega, two-equation turbulence model, has been used to predict the occurrence of complex three-dimensional separated regions.

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