为了有效抑制叶顶泄漏流的发展，降低叶顶泄漏损失，针对两级动叶可调轴流风机提出在吸力面构造叶顶小翼并开设斜槽的新型叶顶改型方案。采用Fluent数值模拟了5种叶顶改型方案对风机性能和流场特征的影响，分析了不同方案下流场、叶顶静压、叶顶泄漏量和动叶区做功能力的变化。结果表明：吸力面小翼可有效降低叶顶损失，小翼上开设顺流向斜槽可进一步提高风机性能，逆流向斜槽会使性能略有降低；顺流向单斜槽为最佳改型方案，在设计流量下全压和效率分别提升166 Pa和0.942%；叶顶间隙处产生额外的涡流，叶顶泄漏流得到抑制，动叶区做功能力得以提升。

In order to effectively limit the development of blade tip leakage flow and reduce tip leakage loss, taking a twostage variablepitch axial fan as an object, new blade tip modification schemes for constructing slotwinglets on the suction surface were proposed. The effect of five slotwinglet schemes on the fan performance and flow field characteristics was numerically simulated by using the Fluent. The variations of flow field, blade tip static pressure, blade tip leakage flow and working capacity of rotating blades were analyzed in different schemes. The results show that a winglet on the suction surface can effectively reduce the blade tip loss, and a downstreamslot grooved on the winglet further promotes the fan performance, while a countercurrentslot slightly reduces the performance; a single downstreamslot winglet pattern is the best scheme, and the total pressure rise and efficiency are respectively increased by 166 Pa and 0.942% at the design flowrate; additional vortex is generated in the tip clearance, the tip leakage flow is suppressed, thereby leading to an improvement of working capacity of rotating blades.

TK83