Pressure-Sensitive Paint Investigation for Turbomachinery Application

Two preliminary tests are discussed which investigate the feasibility of using pressure-sensitive paint (PSP) technology to acquire blade surface pressures in turbomachinery. The first test determined the prospect of using PSP in an operational environment. In this test, PSP was applied to a first stage rotor blade of a state-of-the-art transonic compressor. The paint survived the normal operating temperature, pressure, and centrifugal forces present in this compressor at rotational speeds up to 13,000 RPM. The second test investigated techniques to acquire blade surface pressure data. Suction surface intensity measurements were acquired from a low speed, high-aspect ratio compressor using a back illuminated charge coupled device (CCD) camera while the compressor was rotating at 1500 RPM. An optical derotating mechanism was used to hold the rotor blade image stationary while acquiring PSP data. Both experiments demonstrate that PSP is a viable technique to acquire blade surface pressure data in full scale compressor testing. Special considerations required in applying PSP techniques to turbomachinery are also reported.