PRoduction of nOise by flaMe-turbulence intEraction and insTabilities in H2 lEan combUStion (PROMETH2EUS)

This project addresses the fundamental problem of combustion noise in hydrogen flames. To reduce CO2 emissions and reach the targets of the European Green Deal agreements, hydrogen combustion is gaining momentum in the aviation and power generation industries.

Controlling noise emissions is as crucial as pollutant emissions for the competitiveness of combustion technologies. Specifically, as hydrogen flames are thinner and more wrinkled with respect to standard hydrocarbons, a different interaction with turbulence is expected, with more flame pockets release and faster flame surface destruction, which are the basic mechanisms known to lead to noise radiation.

Furthermore, to avoid NOx formation, lean hydrogen combustion is usually preferred, which may lead to the onset of intrinsic thermo-diffusive instabilities. Understanding noise generation in hydrogen flames remains challenging: combustion noise is a highly multi-disciplinary subject combining acoustics, reactive fluid mechanics, and chemistry; high-fidelity numerical simulations are necessary to complement experimental observations and gain in understanding.

In the present project, special attention is given to understand the interplay mechanisms of chemistry, turbulence, instabilities, and acoustics, aiming to unveil all direct noise sources in hydrogen combustion and develop tools to simulate such phenomenon, acquiring knowledge for engineering design of potential green combustion systems.