Characterization of pressure dynamics in an axisymmetric separating/reattaching flow using fast-responding pressure-sensitive paint

Abstract

This collaborative work discusses the results of time-resolved pressure-sensitive paint measurements performed on a model of a generic spacecraft under sub- and transonic test conditions. It is shown that optical pressure measurements using an active layer from platinum–porphyrin complexes (PtTFPP) in combination with a polymer-ceramic base layer are able to measure dynamic flow phenomena in the trisonic wind tunnel facility up to sampling rates of 2 kHz. Low amplitude fluctuations in the order of 0.1 kPa were determined by means of this measurement technique. The buffet dynamics, as well as the spatial extent of the recirculation area in the near-wake, compare well with numerical predictions and PIV measurements. Furthermore, characteristic coherent pressure modes on the base were resolved, which were predicted by large-eddy simulations.