Numerical Investigation of Hydrogen Flame Shape and Structure

Hydrogen combustion is a promising alternative to fossil
fuels, aiding decarbonization and pollution reduction.
However, its unique properties pose challenges in flame
stability, flashback, and NOx emissions. This study
examines swirl-stabilized non-premixed hydrogen flames
using Large Eddy Simulation (LES) to understand flame
dynamics, stabilization, and emissions. Using the
Hydrogen Low NOx (HYLON) burner from IMFT, the
study analyzes attached and lifted flames under turbulent
conditions at an equivalence ratio of 0.45. Fuel flow rates
are 0.032 g/s and 0.08 g/s, and air flow rates are 2.41 g/s
and 6.03 g/s for the attached (case A) and lifted (case L)
flames, respectively. Simulations validated against
Particle Image Velocimetry (PIV) data show strong
agreement in velocity distribution and flow structures.
The central and outer recirculation zones play key roles
in flame stability and NOx formation. Results reveal that
lifted flames emit less NOx due to better mixing, while
attached flames produce more NOx due to prolonged
high-temperature exposure. This research advances
hydrogen combustion knowledge, supporting the
transition to clean energy solutions by addressing key
challenges in combustion modeling, emission control,
and flame stability