Experiment and numerical simulation of the performance on scaled compressor cascade and development of a prediction model

Abstract

In this study, performance variations and predictions of scaled compressor cascades were investigated. A high-subsonic profile from a rotor section of a certain axial compressor was studied. Tests as well as two-dimensional (2D) and three-dimensional (3D) CFD simulations of cascades of different scale ratios were performed to obtain the flow data of 2D and 3D flow conditions. According to the results, a scaling criterion based on aspect ratio of cascade test for the full range of incidence angles was proposed. Test results shows that aspect ratio of 2.16 is sufficient only in the minimum loss condition for test to reflected the performance of the 2D profile. When the aspect ratio was larger than 4.32, the flow at the mid-span of the tests and 3D-CFD results had good two-dimensionality at the range of twice-minimum-loss incidence angles. The relative deviation of 2D and 3D performance was less than 5%. The total pressure loss and deviation angle increased after scaling down. These results were attributed to the change in the Reynolds number corresponding to the scale. Prediction models were proposed for the calculation of the total pressure loss and deviation angle of the original profiles using the results of the scaled profiles based on the boundary layer theory. The models mainly take into account the Reynolds number, and they are applicable for conditions in which the Reynolds number exceeds the critical Reynolds number.