An experimental and theoretical study of three-dimensional boundary layers on bodies of revolution at incidence was conducted during the period May 1980-July 1983. This final report summarizes the technical accomplishments. Reference is made to previous reports and papers resulting from the study and some recent experimental results on the boundary layer in the plane of symmetry and the vortex formation region are presented. One of the primary objectives of this study was to develop instrumentation for the measurement of the mean flow and the Reynolds stresses in three-dimensional turbulent boundary layers, and to use these to supplement the mean-flow measurements made earlier by Ramaprian, Patel and Choi on the combination body at an incidence of 15 degrees.

Surface streamline patterns on three bodies of revolution, namely a spheroid, a low-drag body and a hemisphere-hemispheroid combination body, have been examined at several angles of attack. Most of the tests were performed at low Reynolds numbers in a hydraulic flume using colored dye to make the surface flow visible. A limited number of experiments was also carried out in a wind tunnel, using wool tufts, to study the influence of Reynolds number and turbulent separation. The study has verified some of the important qualitative features of three-dimensional separation criteria proposed earlier by Maskell, Lighthill, Wang and others. The observed locations of laminar separation lines on a spheroid at various incidences have been compared with the numerical boundary-layer solutions of Wang, and it is suggested that the quantitative differences may be attributed to the significant viscous-inviscid interaction, especially at large incidences. (Author).

This report summarizes the objectives and accomplishments of an experimental and theoretical investigation of the boundary layer development on bodies of revolution at incidence. The results of the flow visualization studies in laminar flow, detailed measurements in a turbulent boundary layer, and calculations of laminar as well as turbulent boundary layers using two different numerical schemes and turbulence models are reviewed to emphasize the important characteristics of separation in three dimensions.

Three-dimensional thin boundary-layer equations for laminar and turbulent flows are solved by two different numerical schemes. The methods are applied to the flow over bodies of revolution at incidence and the results are compared with the available experimental data in order to study the range of validity of the classical boundary-layer approximations in regions of increasing circumferential gradients and flow reversal associated with the early stages of a free-vortex type of separation. Comparison with the DFVLR 6:1 spheroid data of Meier et al and the 4:1 combination-body data of Ramaprian, Patel and Choi indicate that the methods perform well in regions where the boundary layer remains thin but the predictions deteriorate as the boundary layer thickens. The results point out the need for the development of methods of handle thick boundary layers and viscous-inviscid interactions. (Author).

The previously investigated three-dimensional boundary layer near the plane of symmetry of an inclined spheroid is extended along three directions: wider range of solutions, explanations to questions left unanswered before, and comparisons with experiments. Extended solutions provide more complete trends for incidences from zero to 90 degrees and for thickness ratios ranging from unity for a sphere to nearly zero for a long inclined sylinder. Among these trends is how the separation changes from one type to another and then back again with increasing incidence. Explanations are given for a number of unconventional features; included here is why the lateral derivative of the cross velocity profile reverses. Agreement with Wilson's recent experiments (designed specifically for partial check of the results obtained earlier) enhances the significance of the investigation undertaken.