Experimental Validation of Unsteady Pressure-Sensitive Paint for Acoustic Applications

Kurzfassung

Unsteady Pressure-Sensitive Paint (iPSP) is evaluated for measurements of acoustic pressure distributions similar to the acoustic pressures found inside the Aeroacoustic Wind Tunnel (AWT). A test facility is designed which allows to measure these acoustic pressure distributions with iPSP. The aim of the evaluation is to detect pressure amplitudes below 100 Pa with multi frequency excitation between 1000...4000 Hz, based on the parameters in AWT. To increase the signal-to-noise ratio the data analysis methods; phase averaging, proper orthogonal decomposition, and dynamic mode decomposition (DMD) are compared to each other and the DMD is identified to be the most powerful for this application. The measurement setup combined with the DMD is capable of detecting pressure amplitudes below 11 Pa in multi frequency phenomena with frequencies up to 4615 Hz. The minimal obtained detectable pressure limit is 5 Pa at 1318 Hz. This results are a good basis for future measurements with iPSP inside AWT.