预旋对周向槽处理机匣扩稳能力的影响

Mechanism of affect on stall margin of circumferential grooves with variable pre-swirl angle

以Rotor 67转子为研究对象,通过数值模拟的手段分析了周向槽(CG)提高转子失速裕度(SM)的机理,并在此基础上研究了周向槽处理机匣与转子前预旋的匹配问题。结果表明:在Rotor 67转子中,叶尖泄漏流与激波相互干渉产生的低速区是转子失速的重要原因,而周向槽内气流离开时形成的与泄漏涡(LV)方向相反的涡会抑制泄漏涡的周向发展,是周向槽的扩稳机理之一。通过分析周向槽处理机匣在不同预旋条件下扩稳效果的变化,显示在不同流量点、不同预旋条件下,随着转子叶尖负荷位置的变化,起主要扩稳作用的处理槽不同,并在此原则下,提出了一种周向槽设计的思路。

Numerical simulations were performed for Rotor 67 to analyze the mechanism of the stall margin(SM)improvement of circumferential grooves(CG)casing treatment,and the matching between CG and pre-swirl angle.Results showed that stall in Rotor 67 was mainly attributable to the low velocity region arisen by the inference of tip leakage flow and shock wave.The mechanism of SM improvement was that the flow from the pressure side of adjacent blade caused a vortex counter-rotating to the leakage vortex(LV),which inhibited the development of LV.The most important groove(s)changed while the distribution of static pressure changed because of the varying mass flow or pre-swirl angle.A design method was presented depending on the research results.