Unsteady pressure measurements in turbomachinery using porous pressure sensitive paint

Abstract

This work demonstrates the capability of porous pressure sensitive paint (porous PSP) to make full unsteady surface pressure measurements in rotating turbomachinery. Response time calibrations with shock tube and oscillating jet experiments show that porous PSP responds to pressure fluctuations as fast as 40 kHz. Porous PSP is used in this work to measure the unsteady pressure fluctuations on the wall of a turbocharger compressor inlet. The blade passage frequency of the compressor ranges up to 10 kHz. This paper also demonstrates the use of PSP on thin turbomachinery components where it is difficult to apply conventional instrumentation. Porous PSP is applied to the blade, measuring only 0.027 thick, for global blade pressure measurements that are steady in the rotating frame. Porous Polymer/Ceramic PSP is used for these tests and demonstrates good adhesion characteristics to rotating parts.