Optimizing compressor rotor–stator assembly process to minimize clearance non-uniformity

Abstract

The circumferential nonuniform clearance of the rotor blade tip significantly impacts aerodynamic stability. Therefore, in the assembly process, the clearance distribution of rotor blade tips at all levels should be as uniform as possible. The aim of this paper is to minimize the non-uniformity of the clearance distribution by optimizing the assembly process parameters of the rotor–stator assembly. The prediction model for clearance non-uniformity was first established using spatial geometric transformation. Then, the influence of factors on clearance non-uniformity was quantified using the Morris method. The normalized sensitivities of the main factors were 0.1242 for the runouts of the rotor blade tips, 0.0998 for the runouts of the runners of the casing, and 0.7759 for the eccentricity of the rear pivot. Therefore, the eccentricity of the rear pivot was the main factor. Furthermore, a process optimization strategy was established based on the sensitivity analysis results. The process optimization of the rotor–stator assembly was completed by considering the rear pivot, rotor blade tips, and casing runners as optimization objects. The test results demonstrated that, by optimizing the assembly state of the rotor–stator assembly based on the optimal process parameters, the overall clearance non-uniformity was reduced by an average of about 85.06% compared to the initial clearance non-uniformity. Specifically, the optimization of the rear pivot and the rotor blade tips reduced the clearance non-uniformity by about 83.3% and 11.65%, respectively, compared to clearance non-uniformity before their respective optimizations. Despite efforts to optimize the runners of the casing, clearance non-uniformity remained largely unchanged.