【作者】 王沛；

【导师】 黄伟光； 朱俊强；

【作者基本信息】 中国科学院研究生院（工程热物理研究所） ， 动力机械与工程， 2007， 硕士

【摘要】 压缩系统中的以旋转失速和喘振为代表的流动失稳现象一直是困扰叶片式叶轮机械设计的难题。对流动失稳的机理进行研究，并实现有效的控制，对于提高压气机的性能和可靠性具有重要意义。以往的研究表明，旋转失速一般经由两种典型的失速先兆产生(模态波型和尖脉冲型)，而失速先兆与叶顶区域的泄漏流动直接关联。本文研究工作的目的是，从改善叶顶区域泄漏流动的角度出发，研究轴流压气机的扩稳方法及其扩稳机理。本文拟采用定常方法和非定常方法相结合的方式，对不同流量工况下叶顶区域的流场特征进行考查，以更深入的认识旋转失速的触发机制。并基于此，分析两种有效的失稳控制策略——周向槽处理机匣和微量喷气提高压气机稳定工作范围的机理，考察了实施控制策略后，叶顶区域流场，尤其是泄漏流动的改善效果。论文内容安排如下：首先，对带实壁机匣的单转子压气机进行了单通道定常和非定常数值模拟，详细的分析了不同流量工况下动叶顶部泄漏流的特性以及损失和堵塞的变化，通过流动失稳触发过程中叶片通道内泄漏流的演化，探讨了泄漏流与流动失稳关联的物理机理。其次，对带具有不同槽数和开槽位置的周向槽处理机匣的单转子压气机内部流场进行了数值模拟，研究了不同的周向槽处理机匣结构对叶顶泄漏流动、压气机总体性能和失速裕度的影响，深入分析了周向槽处理机匣内流动与转子叶顶流场之间的相互作用机制，对比分析了处理机匣引入前后压气机叶顶流场结构的变化特征，解释了这类周向槽处理机匣结构实施后提高压气机稳定工作范围的原因。最后，就叶顶微喷气扩稳的实验结果，采用全三维非定常数值模拟技术对喷嘴与叶片通道之间的气动耦合下的流动特征进行了分析，通过对比研究了微喷气引入前后叶顶流场结构的变化，就稳态微量喷气提高压气机稳定工作范围的机理进行探讨，为下一步进行微喷气拓宽压气机稳定性途径的实际方案设计提供了认识方面的支撑。更多还原

【Abstract】 The phenomenon of flow instability in the axial and centrifugal turbomachinery, including rotating stall and surge, has been a long-standing problem for the turbomachinery design and stable operation. To improve the performance and reliability of compressors, as well as the gas turbines, it is of great importance that the mechanism of unstable flow occurrence is well understood, and furthermore, this aerodynamic instability is successfully controlled. Based on a low-speed axial compressor at Institute of Engineering Thermophysics, variations of tip leakage flow and internal flow within blade passage under using of two passive control methods, circumferential grooves casing treatment and micro injection are discussed in details with the help of numerical simulation results. Mechanism of stall margin improvement with the above-mentioned passive control strategy is realized in this paper.Steady and unsteady numerical simulations are employed to investigate the character of the tip leakage flow and the change of loss and storage in different flow conditions. Then, the physical processes occurring when approaching stall have been assessed and, the influences of complex tip flow on flow instability has been analyzed.The flow field through the axial compressor rotor with circumferential groove casing has been simulated to investigate the effects of the number of grooves and the location of the grooves on the performance and stability of the compressor. Numerous studies were focused on the interaction between the complex tip flow and circumferential groove casing treatment. Detailed analyses of the flow visualization at the rotor tip have exposed the different tip flow topologies between the cases with treatment casing and with untreated smooth wall. It was found that the primary stall margin enhancement afforded by circumferential groove casing treatment should be a result of the tip flow manipulation.Based on the result of micro injection experiment, the coupled flow through the axial compressor rotor and the injector is simulated with a state-of-the-art multi-block flow solver. The performance and the primary stall margin improvement are investigated in the case with tip injection. The relationships between the unsteady tip leakage vortex and the rotating stall for smooth wall and micro tip injection have been researched. It is the key to clarify the developing process of such unsteadiness through numerical simulations and to explore its effects on the stall inception. It should be helpful to utilize the above-mentioned computation results for designing the effective passive control method in industry.更多还原