Optical investigation of transient phenomena in hypersonic shock tunnels

Abstract

Three different applications of high-speed near-resonantly enhanced shearing interferometry to visualise and investigate hypersonic wake flows are described. In the present application, two axisymmetric objects, a sphere and a model of a planetary entry vehicle, are placed in a Mach 10 shock tunnel flow. The influence of different mounting structures on the wake flow of the entry vehicle is demonstrated. Planar laser induced fluorescence (PLIF) thermometry is used as an additional tool to monitor base flow temperatures. The unsteadiness of the wake flow of the sphere is compared to the flow unsteadiness around the entry-probe. The velocity in selected parts of the wake flow field is also determined with the help of a time-resolved time-of-flight method. Show more