Large-Eddy Simulation of a Swirl-Stabilized, Lean Direct Injection Spray Combustor

Large-eddy simulation (LES) of a lean-direct injection (LDI) combustor is reported in this paper. The full combustor and all the six swirl vanes are resolved and both cold and reacting flow simulations are performed. Cold flow predictions with LES indicate the presence of a broad central recirculation zone due to vortex breakdown phenomenon near the dump plane and two corner recirculation zones at the top and bottom corner of the combustor. These predicted features compare well with the experimental non-reacting data. Reacting case simulated a liquid Jet-A fuel spray using a Lagrangian approach. A three-step kinetics model that included CO and NO is used for the chemistry. Comparison of mean velocity field predicted in the reacting LES with experiments shows reasonable agreement. Comparison with the non-reacting case shows that the centerline recirculation bubble is shorter but more intense in the reacting case.