Self-excited instabilities in aero- and thermoacoustics

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.