Air injection is an effective method to eliminate flow separation and improve blade loading in compressors. In existing studies on unsteady air injection, achieving a better control effect than steady injection with lower injection consumption is a major difficulty and challenge. In this work, pulsed endwall air injection (PEAI) was carried out numerically in a highly loaded compressor cascade under different injection frequencies and injection amplitudes. The mechanism through which PEAI influences corner separation and vortical flow, especially the effect of initial injection phase on the flow field of compressor cascade, was revealed. The results showed that PEAI effectively suppressed the corner separation with lower injection mass flow rate compared with steady endwall air injection (SEAI). The time-averaged overall loss coefficient and endwall loss coefficient were reduced by 10.5% and 28.7%, respectively, under the optimal PEAI scheme. Higher injection amplitude exhibited a more effectively controlled range in the suction corner, which led to a decrease in corner separation and deterioration of the mid-span flow field. The interaction between trailing edge separation and low-momentum fluid at mid-span led to the formation of an injection vortex. When conducting PEAI, the effect of inertia was observed for flow in the injection hole, which was derived from the interactions between injection fluid at different velocities and will increase with the improvement of injection frequency. The effects of injection location and diameter of the injection hole were also investigated. The injection location of PEAI affected the flow field by changing the effect region of the injection and low-momentum fluid near the endwall. The injection hole diameter had a significant impact on the intensity of the passage vortex and mid-span flow field.

空气喷射是消除气流分离和改善压缩机叶片负载的有效方法。在现有的非定常注气研究中，以较低的注油消耗实现比稳注更好的控制效果是主要的难点和挑战。在这项工作中，脉冲端壁空气喷射 (PEAI) 在不同喷射频率和喷射幅度下在高负载压缩机叶栅中进行数值计算。揭示了PEAI影响角分离和涡流的机理，特别是初始喷射阶段对压气机叶栅流场的影响。结果表明，与稳定端壁空气喷射 (SEAI) 相比，PEAI 以较低的喷射质量流量有效地抑制了角分离。在最优 PEAI 方案下，时间平均总损耗系数和端壁损耗系数分别降低了 10.5% 和 28.7%。较高的喷射幅度在吸入角处表现出更有效的控制范围，这导致角分离减少和跨中流场恶化。跨中后缘分离与低动量流体的相互作用导致注入涡的形成。在进行PEAI时，观察到注入孔内流动的惯性效应，该效应源于不同速度的注入流体之间的相互作用，并且随着注入频率的提高而增加。还研究了喷射位置和喷射孔直径的影响。PEAI的注入位置通过改变注入和端壁附近低动量流体的作用区域来影响流场。喷孔直径对通道涡和跨中流场的强度有显着影响。