Phase Delay and Correlation Area Detection of Unsteady Pressure Field Using Unsteady PSP Measurement

Abstract

An unsteady Pressure-Sensitive Paint (PSP) measurement using a high-speed camera was applied to an unsteady pressure field with trailing-edge noise on a 2-dimensional NACA0012 model. The model chord length was 250mm. Uniform flow speed was U=28m/s and Reynolds number was Re=4.9×10. Unsteady PSP measurement was conducted at the angle of attack of =-1.5°, -2.5°, and -4°. Unsteady PSP data reduction was introduced spectral analysis and averaging to increase signal-to-noise ratio of unsteady data processing. 4 kinds of unsteady flow field information were processed through the unsteady PSP data reduction; power, coherence, phase, and phase velocity of the unsteady pressure as maps on the test model. Detail of the data reduction to produce 4 kinds of unsteady flow filed information and the results of the unsteady PSP measurement on the NACA0012 model were introduced.