Experimental and Computational Investigation of a Swept-Wing Flow at Subsonic Speeds

Abstract

The paper reports on an experimental and computational investigation of the flow on a portion of an aircraft swept wing in a wind tunnel at low speeds. The range of angle of attack covered the domain encountered by the aircraft, and the actual outer part of a wing was used for the tests. The experiments included static pressure distributions in the leading-edge region, as well as the rest of the chord; shear-stress measurements in the leadingedge region, obtained with heated film gages; and skin-friction measurements on the main part of the wing, obtained with modified Preston tubes. Velocity profile data across the boundary layer were taken in a smaller region, and some measurements of the turbulence characteristics at a few locations on the main wing were also taken. The pressure distribution was shown to be satisfactorily represented by patching a two-dimensional inviscid method in the leading-edge region and a three-dimensional panel method on the main wing. Starting from this, boundary-layer calculations were performed with Bradshaw's finite-difference program for straighttapered swept wings, where different spanwise stations were calculated separately. The results are encouraging, as the estimated skin-friction magnitude and trends with Reynolds numbers were predicted reasonably well.