Numerical investigation of the influence of suction surface synthetic jet on the performance of transonic axial flow compressor

In order to investigate the effect of suction surface synthetic jet on the aerodynamic performance of transonic axial compressor, Rotor35 was used for numerical simulation. The results show that at four different positions, the stability margin of the compressor is slightly reduced by suction surface excitation, but there is an optimal position that can improve the compressor total pressure ratio and efficiency. At this position, there is little change in the total pressure ratio at the peak efficiency, and the efficiency is improved by 0.58%. The total pressure ratio and efficiency of the design point are increased by 0.18% and 0.55%, respectively. The periodic excitation of synthetic jet can effectively separate the suction surface and reduce the separation loss, which is the reason for the improvement of compressor efficiency. However, for the transonic compressor, synthetic jet on the suction surface obstructs the radial migration vortex that reaches the tip to the exit, but cause it to gather in the tip channel, resulting in the blockage and reduction of the stability margin of the compressor. In order to take into account the stability margin of the compressor, the coupled flow control is carried out by combining the casing treatment with synthetic jet on the suction surface. The results show that the flow margin of the compressor is increased by 8.76%, the total pressure ratio is increased by 1.76%, and the efficiency is only decreased by 0.13%. In coupled flow control, the suction and injection effects of the casing treatment can make up for the negative influence of synthetic jet on the tip flow, effectively improve the tip flow and expand the stable working range of the compressor. Compared with flow control that only carries out casing treatment, coupled flow control can exert the advantages of synthetic jet suppressing suction surface separation, reduce shock loss, outlet loss and casing treatment loss, and make up for the shortage of excessive efficiency reduction after casing treatment, which is the main reason for the improvement of compressor performance.