缝式机匣处理对跨音速压气机稳定性影响的数值研究

【作者】 迟志东； 楚武利； 张皓光；

【机构】 西北工业大学动力与能源学院；

【摘要】 本文通过非定常数值模拟方法,详细研究了轴向缝式机匣处理缝深变化对跨音速压气机性能的影响规律。为了弄清不同结构参数处理机匣带来扩稳的内在机理,采取非定常数值计算并设置了包含深宽比变化的4种轴向缝处理机匣结构。结果表明随着深宽比从大到小,处理机匣的扩稳能力先增加后减小,且深宽比为2:1时扩稳裕度最大为14.78%,当深宽比小于1时,扩稳裕度明显减小(仅为9%)。为了量化分析缝式机匣处理对压气机稳定裕度的影响,本文通过在缝式机匣处理开口面处积分方法,得到了机匣处理缝内流体与转子叶顶流体之间的流量、动量交换过程及量值大小变化规律。通过对缝式机匣处理与转子叶顶耦合作用下的流场进行可视化分析,发现缝式机匣处理通过对叶顶间隙泄漏流进行周期性的抽吸与喷射作用,有效消除了叶顶泄漏涡破碎带来的叶顶大范围通道堵塞,使得叶顶泄漏流与主流交界面向通达内移动,因此压气机能够在更低的流量工况下稳定工作。更多还原

【Abstract】 This article presented the time-accurate numerical study of axial slots casing treatments(ASCT) in an axial transonic compressor rotor. For the aim of enhancing stall margin and further figuring out the internal mechanisms of ASCTs, the simulations comprised 4 configurations with different depth-width ratio. All 4 casing treatments studied proved to have a beneficial effect on stall margin improvement while maintained high levels of compressor adiabatic efficiency. Larger depth-width ratio slots showed the better potential, the stall margin enhancement reached the maximum 14.78% when the depth-width is 2:1, but the depth-width ratio less than 1, the stall margin improvement dropped sharply. The flow rate and momentum change under the action of casing treatment and tip leakage flow are quantitatively analyzed in detail. Detailed flow field visualization analysis revealed the stall mechanism of smooth wall and stall margin improvement mechanism of ASCTs. Compared to the smooth wall case, the treated casing significantly reduced blockage in the tip area and weakened the roll-up of the core vortex. These mechanisms prevent an early spillage of low momentum fluid into the adjacent blade passage and delay the onset of rotating stall. Furthermore, unsteady flow field analysis presented the effect of casing treatment on the compressor performance.更多还原