Investigation On Performace Optimization Of Transonic Low-reaction Compressor Rotor

Low reaction compressor rotor can achieve high load and effective flow, Control the flow of fluid by the boundary layer suction in the stator, so as to realize the high efficient and load aero dynamic performance of the compressor. Song Tao.W from Harbin Institute of Technology design a three-stage transonic high-load and low-reaction compressor by the method of equal intermediate diameter whose rotor at first stage can achieve higher pressure ratio and efficiency, but the surge margin is relatively low, so in this paper, the transonic low reaction blade is designed by the method of equal intermediate diameter and external diameter, whose efficiency is higher than 92%,and the pressure ratio is higher than 2.6.First of all, Rotor37 is simulated to verify the reliability of the result of numerical simulation software NUMECA. Under the condition that on the wall y+ is in the range of using the turbulence model, only changing the number of the grid study on the influence on the result of the numerical simulation. Then the result of the numerical simulation is compared with the experimental data. It can be found that, when the number of grid is more than 770 thousand, the numerical simulation results almost does not change. The simulation results of NUMECA is reliable.Then, the performance of the rotor designed by the method of equal intermediate diameter is compared with the rotor designed by the method of external diameter. The comparison results show that the efficiency of the former is higher than the latter in the whole operating range, and the total pressure ratio is also higher than the latter near the design point, but the surge margin is smaller than the latter. Considering the total pressure ratio and efficiency, the meridional channel of the rotor designed by the method of equal intermediate diameter is optimized. The optimization results show that the optimization of rotor can enhance total pressure ratio, efficiency and stall margin.Next, changing the gap and the solidity is researched. It can be found that, as the gap increases, the total pressure ratio, efficiency and surge margin gradually reduced. The peak efficiency and flow mass of the rotor will decrease with the increase of solidity.At the same time the place of shock will move to upstream and the strength will reduce with the raise of the solidity.Finally, blade bowing and sweeping technique is applied in the rotor. The research results show that, the forward sweep, negative bow and the combined of the former two is beneficial to improve the rotor stall margin, at the same time can ensure the total pressure ratio and efficiency in a very small range. While the positive bow will make the total pressure ratio, efficiency and surge margin decreased.