Experimental investigation of supersonic flow over a hemisphere.

The experimental investigation of supersonic flow over a hemisphere was conducted using Nanoparticle-based Planar Laser Scattering (NPLS) technique in a supersonic quiet wind tunnel at Ma=2.68. Ahead of the hemisphere, boundary layer separation with the formation of a three-dimensional separated flow was observed, which was resulted from the interaction between the three-dimensional bow shock wave and the boundary layer. The complex flow structures of supersonic flow over the hemisphere were visualized. Based on the time correlation of NPLS images, time-space evolutionary characteristics of supersonic flow over the hemisphere were studied, and the evolutionary characteristics of the spanwise and streamwise large scale vortex structures were obtained, which have the features of periodicity and similar geometry. [ABSTRACT FROM AUTHOR]