Green hydrogen has the potential to help decarbonize the gas turbine industry. However, hydrogen combustion can result in high NOx emissions, an increased risk of flame flashback, and a higher thermal load on the combustor hardware. CFD studies can help engineers gain insight into the feasibility and operability of hydrogen-fueled burners to address these challenges. In this study, we simulated a dual swirl coaxial injector, called a HYLON (Hydrogen Low NOx) burner, with low fuel and air flow rates which resulted in an attached flame. CONVERGE’s SAGE detailed chemistry solver and LES turbulence modeling allowed us to capture the complex combustion kinetics of hydrogen in the turbulent burner environment. Furthermore, we employed temperature-based Adaptive Mesh Refinement (AMR) to help track the flame with a lower total cell count.

The video begins with a view of the burner geometry, first showing the air swirlers, and then revealing the internal geometry. To visualize the flow inside the burner, streamlines representing air (blue) and hydrogen (turquoise) are shown at 0:17. At 0:25, the view switches to a realistic flame rendering visualized by mole fraction of OH. You can see that the flame is attached to the fuel tip. A volume rendering of the time-averaged mole fraction of OH is shown at 0:39. A split view is displayed at 0:44, with a vertical slice showing OH mole fraction (turquoise=low; red=high) on the left and a vertical slice of hydrogen mole fraction (blue=low; red=high) on the right. You can see that the hydrogen fuel is consumed by the flame. A vertical slice of velocity (dark blue=low; light blue=high) is shown at 0:55, and a vertical slice of temperature (blue=low; red=high) is shown at 1:01. At 1:07, the mesh is overlaid on the slice. The video then zooms in and slows down to better visualize how AMR dynamically adds and removes cells to capture the flame.

Convergent Science's CONVERGE is an innovative computational fluid dynamics (CFD) software that eliminates the grid generation bottleneck from the simulation process through autonomous meshing.