Impact of Nonuniform Stagger Angle Distribution on High-Pressure Compressor Rotor Performance

Abstract

The focus of the present study is to find a solution to the manufacturing tolerances of rotor stagger angle in the high pressure compressor. The manufacturing processes of compressor blades may lead the stagger angle to be out of tolerance, which would reduce the performance of the high-pressure compressor. Meanwhile, the assembly may cause the nonuniform distribution of the variable blades. To investigate the influence of stagger angle variability and its nonuniform distribution in multiple passages, amount of 3D numerical simulations of a high pressure compressor rear-stage rotor were conducted in the present paper. The Gaussian Probabilistic Density Function was used to obtain the sampled blades with variable stagger angles, and then the blades were randomly allocated in a single passage to a half period, respectively. Numerical results show that with the increase of passage number, the total performance varies more stably. In order to get an appropriate tolerance range of the stagger angle to control the deterioration of the total performance, different ranges were tried, and [−1.5°, +1.5°] was determined as the final range to do further analyses. The different stagger angle distribution along the circumferential direction of a specific group of several sampled blades led to the different performance variations. When the stagger angle distribution approximately satisfied the sinusoidal function during assembly, the rotor performance was better than other distributions. Hence, the sinusoidal function during assembly is an effective solution to the manufacturing tolerances of rotor stagger angle.