Comparison of Unsteady Pressure-Sensitive Paint Measurement Techniques

Abstract

The current work focuses on the development and application of fast-responding polymer/ceramic pressure-sensitive paint (PSP) as an advanced surface pressure measurement technique for unsteady flow fields in large-scale wind tunnels. Three different experimental methods for acquiring quality PSP data are discussed: phase-averaging, realtime data acquisition using a high-speed camera, and single-shot lifetime. The three techniques are all demonstrated on a benchmark test case, resolving the unsteady surface pressure distribution on a hemispherical dome tested in the United States Air Force Research Laboratory’s Trisonic Gasdynamics Facility. The hemispherical dome was tested at a freestream Mach number of 0.6 with a total pressure of 1500 psf, where the Reynolds number was 2.4x10. At this flow condition, a predominant shear layer oscillated at 400 Hz over the test model, causing pressure fluctuations on the aft portion of the model. An assessment of the three techniques is presented, with the strengths and disadvantages for each technique evaluated through example.