Self-excited instabilities in aero- and thermoacoustics

由流-声或流-火焰-声反馈机制产生的自激振荡可以在诸如发电厂或气体输送系统的应用中产生非常高水平的脉动。这种脉动可能导致相当大的环境、可靠性和安全问题，因为它们增加了噪音或污染物的排放，以及振动和结构疲劳。相反，热声发动机和制冷机明智地诱导和利用自持振荡发电或冷却。SelfiXs项目将利用非厄米特系统物理学的最新成果。从一个原始的角度来看，重点是扰动能量的产生和消除，该项目将研究一般的流动（火焰）声耦合，特别是最近发现的局部模式。SelfiXs致力于探索和开发新的空气声学和热声学设计原理和工具，这将促进安全、可靠的能量转换和分配技术的发展，降低有害的自激不稳定性的风险。此外，研究结果将支持热声装置的设计，在低温下将废热转化为电能，提高性能和效率。

Self-excited oscillations resulting from flow-acoustic or flow-flame-acoustic feedback mechanisms can generate very high levels of pulsations in applications such as power plants or gas transportation systems. Such pulsations can lead to considerable environmental, reliability and safety problems, as they increase emissions of noise or pollutants, as well as vibrations and structural fatigue. Conversely, thermoacoustic engines and refrigerators judiciously induce and exploit self-sustained oscillations for power generation or cooling.The SelfiXs project will exploit recent results obtained in the physics of non-Hermitian systems. From an original perspective, which focuses on the generation and annihiliation of perturbation energy, the project will study flow-(flame-)acoustic coupling in general and recently discovered localized modes in particular. Analytical models as well as simulation tools will be developed and validated against new experimental data.SelfiXs strives to explore and develop novel design principles and tools for aero- and thermo-acoustics, which will foster the development of secure, reliable technologies for energy conversion and distribution with reduced risk of detrimental self-excited instabilities. Furthermore, the results will support the design of thermoacoustic devices that convert waste heat at low temperature into electrical power with increased performance and efficiency.