Turbulence Intensity and Length Scale Measurements in Multistage Compressors

Abstract

This paper describes the measurement and processing of turbulence data from multistage low-speed compressors. Measurements were made at the same relative positions in three four-stage compressors, each having different levels of the design stage loading coefficient. A new method of data processing to calculate turbulence intensities and integral length scales is outlined. Using this method, integral length scales have been measured in turbomachinery flows for the first time. It is shown how the turbulence intensity and integral length scale vary with position in the blade passage, with changing flow coefficient and with the value of the design stage loading coefficient. The results have been used to specify representative inlet conditions for experimental rigs and to improve the application of CFD turbulence models to turbomachinery modeling.