高负荷风扇位置寻优周向处理机匣扩稳

Stability Enhancement of Highly Loaded Fan with Position-Optimized CircumferentialCasing Treatment Grooves

中文关键词:  扩稳  高负荷风扇  风扇失速  处理机匣  均布周向槽  位置寻优周向槽  航空发动机

英文关键词:stability enhancement  highly loaded fan  fan stall  casing treatment  uniformly-distributed circumferential grooves  position-optimized circumferential grooves  aeroengine

中文摘要:

      为了获得具有扩稳能力和对风扇性能影响小的处理机匣方案，以高负荷风扇为研究对象，采用数值仿真方法研究了实 壁机匣、均布周向槽和位置寻优周向槽下的风扇流场结构，分析了均布周向槽和位置寻优周向槽的扩稳机理；通过试验验证了位 置寻优周向槽设计参数对流场的影响。结果表明：周向槽处理机匣对高负荷风扇叶尖泄漏涡与激波干涉后形成的堵塞区有正向 的作用，可以使风扇的稳定裕度提高2.7%～3.7%；叶尖激波-泄漏流相互干扰形成泄漏涡的位置为提高风扇稳定性的关键位置， 在叶尖低速区的中间弦长位置对减轻叶尖堵塞情况十分有利，处理机匣设计应覆盖这2个位置；周向槽处理机匣槽的数量对风扇 效率有一定的负面影响，需要用尽量少数量的周向槽覆盖在叶尖的关键位置来完成风扇扩稳作用。经过分析可知，位置寻优周向 处理机匣在扩稳综合能力上更具优势。

英文摘要:

      A highly loaded fan was taken as the research object to obtain a casing treatment scheme with stability enhancement capability and less impact on fan performance, the flow field structures under conditions of the solid-wall casing, the casing with uniformly- distributed circumferential grooves, and the casing with position-optimized circumferential grooves were numerically simulated, and the stability enhancement mechanisms of the uniformly-distributed and the position-optimized circumferential grooves were analyzed. The influences of the design parameters of the position-optimized circumferential casing treatment grooves on the flow field were verified experimentally. The results show that the casing treatment with circumferential grooves has a positive effect on the blockage region formed by the interaction of the tip leakage vortex and tip shock of the highly loaded fan, which can significantly increase the stability margin of the fan by 2.7% to 3.7%; the location of the leakage vortex formed by the interaction between the tip shock and the leakage flow is the key loca? tion for fan stability enhancement, the mid-chord position in the low-speed region of the blade tip is extremely effective for tip blockage alleviation, the casing treatment design should cover these two locations; the number of the circumferential casing treatment grooves adversely affects fan efficiency to a certain extent, so it is necessary to cover as few circumferential grooves as possible at key positions of the blade tip for achieving stability enhancement. The analyses show that the casing treatment with position-optimized circumferential grooves has more advantages in overall stability enhancement capacity.