Structural design of a small cryogenic wind tunnel compressor rotor

The axial compressor is the power equipment of the cryogenic wind tunnel. It has the characteristics of the wide temperature range and high speed of operation. The compressor rotor structural design was studied in this paper. Key technologies of the compressor design were discussed in detail, including shaft-hub connection, hub-blade connection, bearing selection, lubrication method, seal structure, heat protection scheme, et al. The compressor rotor dynamical characteristics under elastic supporting was calculated using the FEM method. The thermal-structure coupling simulation of the rotor was conducted. Calculation results show that the rotor critical speed is much higher than the maximum speed, the maximum stress value of the thrust bearing housing is about 170MPa when the temperature dropping stage ends, and the safety factor is bigger than 1.5. United debugging of the compressor on a small cryogenic wind tunnel was carried out. Experimental results show that when the total temperature of the wind tunnel drops to 110K, the bearing temperature is higher than 5℃, and the bearing vibration value is lower than 3mm/s. They both meet the design requirement, which verifies that this compressor rotor design is reliable.