LAUSR

Abstract Supersonic planar wake has strong instability characteristics due to its complex flow component, such as wake/shear layer, attachment, and complex shock waves interferences. In this experimental study, an asymmetric supersonic planar wake, with Mach numbers of 1.37 and 2.39 on the upper and lower side, is investigated by Nanoparticle-based Planar Laser Scattering (NPLS) technique. The blending thickness of the re-development mixing layer and the position of the re-attachment point are analyzed. Results show that the flow phenomenon of the re-development mixing layer is unsteady. The flow state of the mixing layer can be small scale structures or large scale coherent structures. The distribution of re-attachment points in the polar map shows the spatial unsteadiness of near-wake. Besides, the streamwise instability is dominant. The streamwise span of the re-attachment points is consistent with the thickness of the plate. By correlation analysis, the flow state of the mixing layer is not sensitive to the position change of the re-attachment point.