Circumferential nonuniformity will always exist in a compressor flow field due to manufacturing inconsistencies, eccentricities, and slight inlet flow nonuniformities. Consequently, discrete stationary measurements can be skewed and contribute to uncertainty in calculated one-dimensional performance. Thus, this research characterizes vane wake variability in a three-stage axial compressor and explores the implications on efficiency calculations. Detailed circumferential traverses with seven-element total pressure and total temperature rakes downstream of each vane row were completed. Results show that wake width circumferential variability is more sensitive to spanwise location than wake depth variability. For this compressor with a pressure ratio of approximately 1.3 at peak efficiency, the observed efficiency variations based on pressure and temperature variations are on the order of three points for the overall compressor, but up to 15 points for individual stage efficiency. Additionally, vane wake variability implications on rotor forced response are explored. Results show that the measured levels of wake variability lead to more than a 60% difference in spectral magnitudes of the fundamental forcing frequency. Thus, the error associated with the difference between the measured wake and average wake should be considered when comparing measurements to computational results which often assume perfectly periodic geometry and uniform inlet conditions.
All Science Journal Classification (ASJC) codes
- Aerospace Engineering
- Fuel Technology
- Mechanical Engineering
- Space and Planetary Science