Numerical Investigation of Active Flow Control of Blade Synthetic Jet on Performance and Stability of Transonic Axial Compressor Rotor

To investigate the influence of blade synthetic jet on the aerodynamic performance and stability of a transonic axial flow compressor, NASA Rotor35 was selected as the object of numerical simulation in this paper. The results show that the stability margin of the compressor is slightly reduced by the suction surface excitation at four different positions, but there is an optimal position that can improve the compressor's total pressure ratio and efficiency. At this position, the total pressure ratio of the compressor at the peak efficiency point hardly changes, with an efficiency increase of 0.58%. At the design point, the total pressure ratio and efficiency increased by 0.18% and 0.55% respectively, and the near-stall condition point is increased by 0.33% and 0.16% respectively. The reason for the analysis is that the stall of the compressor is mainly caused by blockage in the blade tip. Although synthetic jet can effectively blow and suck the migration vortex, reducing the separation loss of the suction surface, because the excitation position is only on the suction surface, the blockage of the compressor is more than that of the prototype, resulting in a slightly decreased stability margin of the compressor. Then, to balance the stability margin, the coupled flow control is carried out by combining the processing of the axial inclined slot casing treatment with the synthetic jet on the suction surface of rotor blade. The results show that after coupled flow control, the flow margin of the compressor increased by 8.76%, the total pressure ratio increased by 1.76%, and the efficiency decreased by only 0.13%. The shock wave loss, outlet loss and casing treatment loss are reduced compared to the flow control with simple casing treatment, which is the main reason for the improvement of compressor performance.