Effect of pulsed jet generated by boundary condition and fluid oscillator on the cascade performance

By introducing pulsed jet with boundary condition styles and fluidic oscillator on the upper end wall, the paper analyzes, through validated numerical simulation, the impact of the two jet methods on the aerodynamic performance and flow field structure of the compressor cascade under different jet positions. The results show that under the frequency doubling condition of the prototype flow field, the boundary condition jet scheme demonstrates better performance at the positions of 76% and 86% axial chord, whereas the oscillator jet scheme exhibits superior control at the 96% axial chord position. The pulsed jet with jet pipe reduces the total pressure loss by a maximum of 10.51%, while the pulsed jet with fluid oscillator decreases the total pressure loss coefficient by 9.24%. After the two types of jets interact with the cascade flow field, the intricate flow conditions within the flow field exert varying influences on the pulsed jet. Specifically, the boundary condition-style jet increases the jet velocity due to the pressure difference between the inlet and outlet. Conversely, the oscillator jet reduces the outlet velocity due to the decreased pressure ratio between the inlet and outlet, ultimately resulting in the differences in the control performance of the two schemes. At the 76% and 86% of the axial chord positions, the boundary condition jet injects additional momentum into the low-energy fluid within the corner region, effectively inhibiting the development of trailing-edge shedding vortex, narrowing the range of corner separation, and decreasing cascade losses. At the position of 96% axial chord, which is near the trailing edge of the cascade, the high-momentum fluid from the boundary condition jet enhances flow mixing. The pressure difference that had increased on both sides of the trailing edge causes significant deflection of the jet fluid, thereby reducing the control effectiveness. In contrast, the oscillator jet significantly reduces the intensity and scope of passage vortex and trailing-edge shedding vortex, lowering the turbulent kinetic energy in the area and decreasing mixing losses.