双排对转压气机叶顶泄漏流三维重构方法及其控制策略研究

The detailed characteristic of unsteady flow (wake shedding, clearance vortex, terminal area flow, etc.) in counter rotating compressor is substantially differentiated from the traditional compressor. This is one of the basic driving force of scientific research in turbomachinery.This project is targeting to understand the mechanism of flow instability and its control strategy for an axial dual-stage counter-rotating compressor. The present research will proceed with the unsteady tip leakage flow structure and its developing. Firstly, in order to mend the SPIV field gap, a new method based on the iteration of coupling the unsteady Navier-Stokes equations and SPIV velocity field is proposed. At the same time the unsteady pressure distribution of the SPIV region will also be obtained by this method.Secondly, with the hope to illustrate the unsteady features, reveal the originating mechanism, and explore the relation between the unsteady leakage flow and rotation stall, the three-dimensional unsteady flow structure of tip leakage with different tip clearance, axial space and rotation speed is captured by numerical and experimental ways.Finally, self-recruitment passages on the shroud of the two counter-rotating rotors will be built to study the effect of removal the tip leakage flow on flow structure in rotor passage and tip clearance. A new controlling technique of the counter-rotating compressor stability will be put forward on the base of the control model with the parameters of rotation speed, blade setting angle of inlet vane, mass flow rate of self-recruitment. The results will provide a new perspective which could further understanding and control the time-space development of tip clearance flow in counter rotating compressor,and might be the foundation of designing a compact, high efficiency and stable counter-rotating compressor.

对转压气机内部非定常流动细节（尾迹脱落、间隙涡、端区流动等）与传统的压气机内部流动有本质的区别，是基础科学研究的驱动力之一。本项目以试验研究和理论分析结合的方式，开展对转压气机间隙泄漏流三维重构方法及其调控策略研究。首先，通过实验测量与理论分析耦合迭代方式，发展一种对转压气机三维细观流动重构新方法；其次，以该方法为主要研究手段，捕捉对转压气机间隙泄漏流的径向迁移、轴向扩展和周向传播的三维时空结构变化规律，研究对转压气机叶顶间隙匹配、轴向间距以及转速匹配等因素对其间隙泄漏流的非定常特征影响机制；最后，研究叶顶间隙泄漏流抽吸/吹除技术（自引气）对上、下游转子通道及间隙泄漏流流动结构的影响效应，发展以转速匹配、"自引气"流量以及进口导叶调节角度等参数为变量的流动控制新模型。研究结果对深入认识并控制对转逆压条件下间隙流动时-空发展效应提供新视角,为设计高效、紧凑和宽裕度对转压气机提供研究基础。

对转压气机内部非定常流动细节与传统的压气机内部流动有本质的区别，是基础科学研究的驱动力之一。本项目以试验研究和理论分析结合的方式，开展对转压气机间隙泄漏流三维重构方法及其调控策略研究。主要研究内容和结果为：（1）开展基于自适应POD混合模型的全三维对转压气机流场分析及流动拟合方法研究，形成了基于正交基函数理论压缩系统复杂三维非定常流动的手段和方法。研究了对转压气机叶顶间隙流动特性，发现了对转压气机非定常性的主要诱发机制，获得了上下游转子波动频率存在较明显差异的重要现象；（2）针对动态压力传感器阵列海量非定常监测数据处理难题，发展了稀疏动态传感器构建叶顶动态压力分布的锁相均方根处理方法，形成了可工程实用的动态压力传感器阵列非定常信号处理手段。研究了对转涵道风扇悬停工况的动态地面效应，发现了风扇喷流动态特性与前后级转子间动-动非定常干涉效应有明显相关性，校验了和补充了Holste提出的动-动干涉轮辐模型。采用非定常数值分析手段研究了对转压气机内转子叶尖非定常流动，获取了其内部非定常流动产生的工况位置、频率特征，捕捉到了对转压气机间隙泄漏流的径向迁移、轴向扩展和周向传播的三维时空结构变化规律；（3）发展了一种三维可压缩稳定性数值模型和解析模型，提出了采用奇异值分解(SVD)法对模型矩阵进行求解，克服大型稀疏矩阵条件数巨大而带来的根植不稳定问题，应用该模型预测了NASA Rotor35和双排对转压气机失速流量工况点，证明了所发展的具有较高的预测精度；（4）以项目研究中对复杂流动机理的认识为基础，在国家留学基金项目资助下派一名学生赴Delft大学攻读博士学位，结合Delft理工大学Fokker F29 Propeller的研究工作，双方联合指导博士生开展基于流动控制的叶片优化设计方面的合作研究，联合发表了多篇高质量国际刊物论文，以项目为载体掌握了有关PIV测量技术以及“盲区修补技术”，为非接触光学测量在叶轮机械复杂流动诊断方面奠定了基础。