双级对转升力风扇性能和流场数值模拟研究

Numerical Investigation of Performance and Flow Field of a Dual-stage Counter-rotating Lift Fan

升力风扇作为短距起飞/垂直降落(STOVL)飞行器的核心部件,在航空领域具有重要的应用价值。以某双级对转升力风扇为研究对象,采用NUMECA数值模拟软件对其不同转速比、不同流量系数工况下的气动性能及内部流场结构进行研究。结果表明:设计转速下,对转升力风扇内流场分布良好,受第一级出口流场影响,第二级转子叶尖部分形成显著的叶尖泄漏流;随转速差的增大,该对转升力风扇的流动损失逐渐增大,流动损失主要由在第二级静子叶片吸力面尾缘部分的流动分离及第二级转子叶尖部分的叶尖泄漏涡导致;在转速差相同时,前面级采用高转速可得到较高气动性能。研究结果以期为我国STOVL飞行器升力风扇的设计提供理论支撑。

As the core component of aircraft,lift fan has high practical value in aviation.In this article,the aerodynamic performance and internal flow field of a designed two-stage counter-lifting fan with different flow coefficient under different speed ratio are studied and analyzed by the NUMECA numerical simulation software.The results show that the flow field in the rotating lift fan is well distributed at the design speed.Under the influence of the flow field at the outlet of the first stage,a significant tip leakage flow is formed at the tip of the second stage rotor.With the increase of speed difference,the flow loss of the rotating lift fan increases gradually,which is mainly caused by the flow separation at the trailing edge of the suction surface of the second stator blade and the tip leakage vortex of the second rotor blade tip.When the speed difference is the same,the high speed of the front stage can obtain higher aerodynamic performance.The research results are expected to provide theoretical support for the design of lift fans for STOVL aircraft in China.