Prediction of acoustic resonance in a multistage high-speed axial compressor

多级高速轴流压缩机中声共振的预测

• 批准号: 468461660
• 负责人: Professor Dr.-Ing. Jörg Seume
• 金额: --
• 依托单位: Institut für Turbomaschinen und Fluid-Dynamik (TFD)
• 依托单位国家: 德国
• 项目类别: Research Grants
• 资助国家: 德国
• 项目状态: 未结题
• 来源: https://gepris.dfg.de/gepris/projekt/468461660?language=en
• 关键词: Prediction; acoustic; resonance; multistage; speed

Economic and regulatory requirements for high operational flexibility of jet engines and power plants lead to more frequent off-design operation of turbomachinery components. Regarding operating stability, the compressor constitutes the most critical and challenging component in these turbomachines. Besides the well-known and intensely investigated aerodynamic instabilities of surge, rotating stall, and rotating instability, high pressure fluctuations have been identified as acoustic resonance in high-speed and high-pressure axial compressors at specific off-design operating points. Recent research shows that acoustic resonance can excite mechanical vibrations, which might result in severe blade damage or immediately fatal structural failure. In addition, research shows that acoustic resonances can shift the stability limit to higher mass flow rates by triggering rotating stall and surge. As several industrial producers of turbomachinery have experienced acoustic resonances there is considerable need for the understanding and characterization on the physical mechanism of this phenomenon for future design processes. First approaches by the applicant and his coworkers have led to two models to predict and characterize acoustic resonance, but data of these phenomena have rarely been reported in open literature. Therefore, validation of these models is necessary. To this end, improved physical understanding of the formation mechanism of the standing waves and of the excitation mechanisms is essential. The objective of the proposed project is to give further insights into the excitation mechanism and the resonance conditions in multi-stage axial compressors. Extensive simultaneous measurements of the tip leakage flow and the resonant acoustic field are carried out for the first time in a high-speed multistage axial compressor, which approximates realistic machine conditions. Based on the highly accurate measurements and numerical simulations, validation and calibration of the prediction models will be performed, which will lead to an approach to predict the occurrence of acoustic resonance.

喷气发动机和发电厂对高操作灵活性的经济和法规要求导致叶轮机械部件更频繁地进行非设计操作。在运行稳定性方面，压缩机是这些透平机械中最关键和最具挑战性的部件。除了众所周知和深入研究的喘振、旋转失速和旋转不稳定等气动不稳定性外，高压波动还被认为是高速和高压轴流压气机在特定非设计工作点的声学共振。最近的研究表明，声学共振可以激发机械振动，这可能会导致严重的叶片损伤或立即造成致命的结构故障。此外，研究表明，声学共振可以通过触发旋转失速和喘振，将稳定性极限转移到更高的质量流量。由于叶轮机械的几个工业生产者已经经历了声学共振，在未来的设计过程中，有相当大的必要了解和表征这种现象的物理机制。申请人和他的同事的第一个方法导致了两个模型来预测和表征声学共振，但这些现象的数据在公开文献中很少被报道。因此，有必要对这些模型进行验证。为此，改善对驻波形成机制和激发机制的物理理解是至关重要的。该项目的目标是进一步深入了解多级轴流压气机的激振机理和共振条件。在一台高速多级轴流压气机上，首次对叶尖泄漏流动和共振声场进行了广泛的同时测量，接近于实际的机械条件。在高精度测量和数值模拟的基础上，将对预测模型进行验证和校准，这将导致一种预测声学共振发生的方法。