Comparison of Large Eddy Simulation with Local Species, Temperature and Velocity Measurements in Dual Swirl Confined Hydrogen Flames

Developing new injection systems and combustion chambers for hydrogen is a central topic for the new generation of engines. In this effort, simulations take a central role, but methods developed for conventional hydrocarbons (methane, kerosene) must be revisited for hydrogen. Validation then becomes an essential part and clean, well documented experiments are needed to guaranty that computational fluid dynamics solvers are as predictive and accurate as expected. In this framework, the HYLON case is a swirled hydrogen/air burner used by multiple groups worldwide to validate simulation methods for hydrogen combustion in configurations close to gas turbine burners, with experimental data available through the TNF web site. The present study compares recent Raman spectroscopy and Particle Image Velocimetry measurements and Large Eddy Simulations (LES). The LES results are evaluated against a dataset comprising mean and RMS measurements of H2 , N2 , O2 , H2O molar fractions, temperature, and velocity fields, offering new insights into flame stabilization mechanisms. The simulations incorporate conjugate heat transfer to predict the combustor wall temperatures and are conducted for two atmospheric-pressure operating conditions, each representing distinct combustion regimes, diffusion and partially premixed. Novelty and significance statement Data on confined hydrogen flames in burner similar as industrial ones are limited. This work aims to fill this gap, by performing multiple and simultaneous diagnostics on the swirled hydrogen-air flame called HYLON. For the first time in such a swirled configuration, mean and RMS fields of temperature, main species and velocities are compared to LES, allowing new insight into the potential and limits of the models as well as the physics of these flames. These experimental results will be made available on TNF, as over 30 research groups worldwide have expressed interest in using them.