Impact of Change in Atomization on Lean Blow Out for Sustainable Aviation Fuels in Gas Turbine Combustors

Sustainable Aviation Fuels (SAF) or alternative jet fuels have fuel properties different from conventional jet fuel. Changes in fuel properties can change the atomization behavior and hence droplet sizes. To understand these effects on spray and flame behavior, Large-Eddy Simulations of the Referee Rig are performed for baseline fuel A-2 and ±5% and ±10% change in the droplet sizes. Increasing droplet sizes result in greater flame spread and upstream flame anchoring compared to the baseline A-2 case, with noticeable differences in droplet distributions within the central recirculation zone but not in the shear layer regions. Conversely, decreasing droplet sizes reduces flame spread and leads to downstream flame anchoring, with differences in droplet distributions observed in the shear layer regions but not in the central recirculation zone. Despite these changes, global combustion behavior such as heat release rate remains largely unaffected, and all five cases blow out within the same range of the global equivalence ratio.