基于载荷优化的跨音压气机叶顶流动和缝式机匣开口面动量输运耦合机制研究

The axial skewed slot casing treatment can significantly improve the stall margin of transonic compressors, but generally causes large efficiency penalty. The blade tip loading of compressors has much effect on the coupling relationship of the momentum transportation through the open surfaces of slot casing and the Blade tip flow, thus affect the pressurization capability in the blade tip region. Therefore, it is necessary to discover the optimal distribution principle of blade loading in the stream-wise direction. In this project application, the effect mechanism of the relative position between the slots and the shock on the blade tip loading distribution will be investigated. The effect of the blade tip loading on the flow losses will be analyzed based on the subsection control volume model of mixing losses. The relationship between the blade tip loading and the interface location of the tip leakage flow and main flow will be analyzed based on the momentum balance model of the free stream and wall jet. Then the reasonable loading method of the blade tip loading in the stream-wise direction will be revealed. The coupling relationship of the key design parameters of the axial skewed slot casing treatment and the tip blade shape will be explored. And the performance of the transonic compressor rotor will be tested with the experiment. The pressure distribution on the shroud surface will be obtained with the equiphase averaged method. In this project application, the coupling design method of transonic compressor blade and slot skewed casing treatment will be established from the perspective of the optimization of blade tip loading. Then the comprehensive aerodynamic performance of transonic compressors can be improved.

轴向倾斜缝机匣处理能够显著提高跨音压气机的失速裕度，但往往会造成较大效率损失。压气机叶顶载荷对缝式机匣开口面动量输运和叶顶流动的耦合关系具有重要影响，从而能够影响叶顶区域的增压能力，因此有必要挖掘缝式机匣处理作用下叶顶载荷沿流向的优化分配原则。本申请项目拟采用非定常数值模拟方法研究缝与激波之间相对位置对叶顶载荷分布的影响机制，基于掺混损失的分段控制体模型分析叶顶载荷分布对流动损失的影响，基于主流和壁面射流的动量平衡模型分析叶顶载荷分布与泄漏流/主流交界面位置的关系，进而揭示缝式机匣处理作用下叶顶载荷沿流向的合理加载方式，探究缝式机匣处理与叶顶叶型关键设计参数之间的耦合关系，并通过试验测试跨音压气机转子性能，利用等相位平均方法获得机匣壁面压力分布，验证理论和数值分析结果。本申请项目预期从叶顶载荷优化的角度建立跨音压气机叶型与轴向倾斜缝机匣处理的耦合设计方法，提高跨音压气机的综合气动性能。

轴向倾斜缝机匣处理能够显著提高跨音压气机的失速裕度，但往往会造成较大效率的损失。为了改善压气机的综合气动性能，有必要深入研究缝式机匣开口面动量输运和压气机叶顶流动的耦合机制，挖掘缝式机匣处理作用下叶顶载荷沿流向的合理加载方式。本项目采用数值模拟方法研究了缝式机匣处理轴向位置和深度变化对跨音压气机气动性能的影响，揭示了缝内回流流动的形成机制以及缝内回流对叶顶泄漏流的影响作用，阐释了缝式机匣开口面轴向动量输运与压气机气动稳定性的关联；开展了缝式机匣处理作用下跨音压气机叶顶叶型改型设计研究，揭示了调整叶顶叶型进出口几何角、安装角、中弧线曲率分布对载荷分布和损失的影响规律；获得了跨音压气机转子叶顶叶型与缝式机匣处理耦合优化设计方案；通过试验测试了采用缝式机匣处理的高负荷压气机气动性能，验证了数值计算方法。本项目建立了跨音压气机叶顶叶型与轴向倾斜缝机匣处理的耦合优化设计方法，在显著提高跨音压气机失速裕度的同时降低了效率损失。研究结果可为高负荷跨音压气机叶型与轴向倾斜缝机匣处理设计提高参考。