Measuring Surface Pressure on Rotating Compressor Blades Using Pressure Sensitive Paint

Area of Science:

• Aerospace Engineering
• Fluid Dynamics
• Experimental Mechanics

Background:

• Radial compressors are critical components in many aerospace and industrial applications.
• Accurate surface pressure measurement is essential for understanding compressor performance and validating computational fluid dynamics (CFD) models.
• Traditional pressure measurement techniques can be intrusive or lack the spatial and temporal resolution required for complex flows.

Purpose of the Study:

• To apply a fast-response pressure-sensitive paint (PSP) technique for non-intrusive surface pressure measurement on radial compressor blades.
• To acquire detailed surface pressure distributions across various operating conditions of the compressor.
• To validate CFD simulations and investigate flow phenomena, including surge, using experimental data.

Main Methods:

• Utilized a fast-response PSP with a diode laser illumination and photomultiplier detection system.
• Employed the "lifetime method" for pressure-sensitive paint measurements.
• Acquired surface pressure data at eight distinct points within the compressor map at rotational speeds up to 50 krpm.

Main Results:

• Successfully mapped surface pressure fields on the compressor blades.
• Demonstrated the capability of PSP to capture high-frequency pressure variations (up to several kHz).
• Identified the pulsating flow frequency characteristic of compressor surge through frequency spectrum analysis.

Conclusions:

• Fast-response PSP is a viable and effective technique for non-intrusive, high-resolution surface pressure measurements in rotating machinery like radial compressors.
• The acquired data provides valuable insights into compressor aerodynamics and serves as a crucial dataset for CFD model validation.
• The method's ability to detect surge frequencies offers a new avenue for studying and mitigating unstable flow conditions.