Applications of PSP

Abstract

This chapter describes PSP measurements in various flows in a range of facilities. Both intensity-based and lifetime-based PSP measurements in high subsonic, transonic, and supersonic flows are first described since PSP is a more effective technique in these flows. Then, unsteady pressure measurements using fast PSPs (porous PSPs) are discussed, which reveal oscillating shock waves interacting with boundary layers in transonic flows and supersonic impinging jet resonant modes. PSP measurements on blunt bodies, rocket models, circular cone, and scramjet nozzle in high-enthalpy hypersonic and shock tunnels using fast PSPs reveal complex shock-wave/boundary-layer interactions, shock-body interactions, and boundary-layer separations. PSP results in low-speed flows where a change in air pressure is very small are obtained when the temperature effect of PSP is carefully compensated and noise-reduction techniques are applied. PSP measurements on rotating blades can be made using the single-shot two-gate lifetime method, as demonstrated in several examples here. Porous PSP is a unique technique for surface pressure measurements in low-pressure flows, and the examples include a low-density impinging jet and wings in the Mars wind tunnel. Other PSP applications include measurements in cryogenic wind tunnels, sonic impinging jets, flight testing, and acoustic resonance box.