This research presents the influence of the low-solidity design on the loss and stability of the cantilevered stator and the evolution of the hub leakage vortex. The highly loaded 4-stage low-speed research compressor (LSRC) with an embedded cantilevered stator (CS) of Stator 3 (S3) was experimentally measured at the blade row outlet and in the S3 passage, respectively, and the URANS simulation method was calibrated accordingly. Then, the prototype CS blade number was reduced, namely low-solidity cantilevered stator (LSCS), to increase the blade loading. The diffusion factor (DF) of LSCS at the midspan at the design working condition is 5.2% higher than that of CS. The URANS results show that LSCS provides higher efficiency for the 1.5 stage compressor with a consistent stall margin. For S3, the total pressure loss of LSCS is lower than CS at the design point (DP) working condition, but it is the opposite at the near stall (NS) working condition. For LSCS at the NS point, the blockage region becomes large and occupies the lower half of the fore blade passage because the low-solidity stator could not provide the enough flow turning ability, and the core of the hub leakage vortex (HLV) moves forward and the intensity is strengthened. The high loss region of LSCS at the near stall condition is consistent with the size of two hub leakage vortices. The first HLV breakdown is caused by unsteady mixing flow, and then it twists downstream and contacts with the trailing edge of the adjacent blade pressure surface. The study of the hub leakage flow characteristics of the low-solidity cantilevered stator can help designers to control flow better.

本研究展示了低密实度设计对悬臂式定子的损耗和稳定性以及轮毂泄漏涡演化的影响。分别在叶片排出口和S3通道处对带有嵌入式悬臂定子（CS）的定子3（S3）的高负载4级低速研究压气机（LSRC）进行了实验测量，URANS模拟方法为相应地校准。然后，减少了原型 CS 叶片数量，即低密度悬臂定子 (LSCS)，以增加叶片载荷。扩散因子（DF) LSCS 在设计工况下跨中比 CS 高 5.2%。URANS 结果表明 LSCS 为 1.5 级压缩机提供更高的效率，并具有一致的失速裕度。对于S3，LSCS在设计点（DP）工况下的总压力损失低于CS，但在接近失速（NS）工况下则相反。对于NS点的LSCS，由于低密实度定子不能提供足够的流动转向能力，轮毂泄漏涡（HLV）的核心向前移动，阻塞区域变大并占据前叶片通道的下半部分并且强度得到加强。近失速状态下 LSCS 的高损耗区域与两个轮毂泄漏涡的大小一致。第一次 HLV 击穿是由不稳定的混合流引起的，然后向下游扭转并与相邻叶片压力面的后缘接触。研究低密实度悬臂定子的轮毂漏流特性可以帮助设计者更好地控制流动。