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.

对喷气发动机和发电厂高运营灵活性的经济和监管要求导致涡轮机械组件的外部设计更频繁。关于操作稳定性，压缩机构成了这些涡轮机中最关键和最具挑战性的组成部分。除了众所周知且经过深入研究的潮流，旋转摊位和旋转不稳定性的空气动力学不稳定性外，在特定的外部设计工作点上，在高速和高压轴向压缩机中，高压波动被确定为高速和高压轴向压缩机中的声音共振。最近的研究表明，声共振可以激发机械振动，这可能会导致严重的刀片损伤或立即致命的结构性衰竭。此外，研究表明，声音共振可以通过触发旋转失速和激增来将稳定性限制转移到更高的质量流速。由于涡轮机械的几个工业生产者经历了声音共振，因此需要对这种现象的物理机理的理解和表征，以实现未来的设计过程。申请人及其同事的首先方法导致了两个模型来预测和表征声学共振，但是在开放文献中很少报道这些现象的数据。因此，必须验证这些模型。为此，必须改善对驻波和激发机制的形成机制的物理理解。拟议项目的目的是进一步了解多阶段轴向压缩机中的激发机制和共振条件。在高速多级轴向压缩机中，首次对尖端泄漏流和谐振的声场进行了广泛的同时测量，该测量值近似于现实的机器条件。基于高度准确的测量和数值模拟，将对预测模型进行验证和校准，这将导致预测声学共振发生的方法。