An Investigation of Strut-Wall Intersection Losses

A study of the intersection losses associated with the junction of a symmetric airfoil and a planar wall is reported. An experimental program, conducted in a low-speed air tunnel, provided detailed wake total pressure profiles as well as surface flow visualization photographs which define the overall flowfield. The behavior of the intersection losses was examined for dependence on flow incidence angle and strut contour. It was found that the endwall intersection losses were strongly dependent on the thickness of the incident boundary layers-thick boundary layers producing markedly lower losses than very thin incident boundary layers. A heuristic model of the flowfield, which explains marked differences between the thick and thin boundary-layer results, is also presented.