Abstract
For the first time in the history of the Mediterranean Combustion Symposium, during its 13th edition (MCS-13, June 2025, Corfu), a minisymposium dedicated to Thermoacoustic Combustion Instabilities was organized. Thermoacoustic instabilities arise from feedback interactions between unsteady heat release, the flow field, and the acoustics of a combustion system. Beyond their fundamental scientific interest as a multiphysics, multiscale phenomenon in reacting flows, they are also of great practical relevance, as they can strongly affect the reliability, safety, and operational flexibility of gas turbines.
The minisymposium attracted considerable international interest, with 17 papers submitted by research groups predominantly from Europe, but also from Asia, the United States, and Australia. The contributions reflected the breadth and vitality of current research in the field. Topics included the characterization and control of instabilities, stability analysis and uncertainty quantification, and investigations of flame dynamics, including flame transfer and flame describing functions. Additional studies addressed swirling and spray flames, the dynamics of (can-)annular combustors and transverse acoustic modes, and the generation, propagation, and damping of perturbations. Several contributions focused on the development of models, numerical methods, and computational tools, including data-driven approaches, as well as nonlinear and stochastic aspects of combustion dynamics. Further work examined staged combustors and jet-in-crossflow configurations, self-propagating flames, and the impact of hydrogen and other carbon-neutral fuels on combustion dynamics.
The minisymposium comprised four thematic sessions: Development of Models, Methods & Tools (chair: Alessandro Orchini, TU Berlin), Characteristics and Control of Instabilities (chair: Preethi R. Soundararajan, University of Southampton), Combustion Instabilities: Flame Dynamics (chair: Wolfgang Polifke, TU Munich), and Impact of Hydrogen on Combustion Dynamics (chair: Oliver Paschereit, TU Berlin). Although these sessions took place on the final day of the symposium, they were very well attended and stimulated lively and insightful discussions among participants.
The success of this minisymposium underscores the continued vitality of research on thermoacoustic combustion dynamics within the international combustion community. Building on this positive experience, a similar minisymposium is planned for the next Mediterranean Combustion Symposium to be held in Marseille in 2027.
Following the conference, several authors were invited to submit revised or extended versions of their contributions to a special issue of the International Journal of Spray and Combustion Dynamics, based on the outcome of the peer-review process. After further rounds of peer review and revision, seven papers were selected for publication in this volume. Collectively, these contributions illustrate the breadth and ongoing development of research on thermoacoustic combustion instabilities. They highlight how the field continues to integrate concepts and methods from other areas of physics and fluid dynamics, while addressing emerging technological challenges, particularly those associated with the transition to carbon-neutral fuels.