Corner separation control by optimizing blade end slots in a linear compressor cascade

Abstract

Corner separation control is studied in this paper on a linear compressor cascade by optimizing the proposed blade end slots. In order to decrease risk of the experiment and obtain a good solution for the end slots considering finite number of calculations, a multi-parameter and multi-objective optimization of the slot to obtain the minimum total pressure loss in the cascade is carried out. Experimental investigation of the optimal slot configuration is conducted and the slot effect on the loss reduction for the compressor cascade has been validated. The slot configuration is optimized at 4° incidence angle to minimize the total pressure loss in the cascade. Measurements are also conducted at 4° incidence angle to validate the optimization procedure and CFD simulations. The layout of the end slot may not be optimal for the whole operating incidence angles for NACA65 cascade, while experiment investigations at 2° and 7° incidence angles with end slot optimized at 4° incidence angle show that total pressure loss is reduced by 5.5% and 23% respectively. The slot configuration can self-adapt the momentum of the jet flow at different incidence angles, due to the change in pressure differential between the pressure and suction surfaces. The blade end slots appear to have significant potential to decrease losses and improve compressor performance and can be applied to the real stator blade to suppress corner separation.