The qualitative structure of linear thermoacoustic modes in gas turbine combustors скачать в хорошем качестве

The qualitative structure of linear thermoacoustic modes in gas turbine combustors

Combustion Webinar 10/9/2021, Speaker: Jonas Moeck Unsteady combustion phenomena arising from the interaction of the flame's heat release with acoustic resonances of its enclosure are ubiquitous in energy conversion devices. In most cases, self-excited combustion oscillations observed in laboratory experiments or full- scale applications originate from a linear instability of the steady operating state. Although a challenging task for complex industrial systems, the onset and characteristics of this undesirable dynamic phenomenon can, in principle, be predicted based on concepts from traditional linear stability analysis, in other words, by solving an eigenvalue problem. Today's power generation gas turbines are predominantly equipped with annular or can-annular combustion chambers. These systems nominally exhibit a high degree of spatial symmetry, and this has strong consequences on the general spectral properties of the thermoacoustic dynamics. I will discuss key features associated with thermoacoustic modes in annular and can-annular configurations, and illustrate their relevance and how they manifest in systems with these combustor architectures. Jonas Moeck is an Associate Professor in the Department of Energy and Process Engineering at the Norwegian University of Science and Technology (NTNU). He received engineering degrees from the University of Michigan and the Technical University Berlin, a PhD from the latter institution and was a postdoctoral scholar at Laboratoire EM2C, Ecole Centrale Paris. His research interests include combustion of carbon- free fuels, flame dynamics, low-order modeling and stability analysis, combustion control, and plasma-assisted combustion. He has received three best paper awards from the ASME related to thermoacoustic modeling.