Visualization of Unsteady Boundary-Layer Transition on Shock-Tube Wall using Highly Sensitive Fast-response TSP

摘要

This paper describes the visualization of unsteady phenomena on the shock tube wall by means of highly temperature sensitive Temperature-Sensitive-Paint (TSP). In hypersonic experiments, the wind-tunnel facilities have the test duration of the order of milliseconds, so that the unsteady global temperature and heat-flux measurements are necessary to understand the unsteady physical phenomena, and which would certainly be a powerful measuring technique. To realize such a transient measurements, the research and development for TSP had been carried out experimentally in shock tube. The developed TSP with the temperature sensitivity more than -4%/K at 293k was applied onto a flat-plate model with less than l|im TSP layer thickness, and installed to the side-wall of shock tube. As a result, TSP could visualize almost of phenomena occurring on the wall. Specifically, the incident shock, the reflected shock, a laminar to turbulent transition, the shock/boundary layer interaction and the interference of the reflected shock and the contact surface were clearly captured by the extracted point measurements and x-t diagram depicted by TSP.