Large Eddy Simulation of a Bluff Body–Stabilized Flame With Close Coupled Liquid Fuel Injection

Abstract

Large eddy simulations (LES) are performed of a bluffbody–stabilized flame with discrete liquid fuel injectors located just upstream of the bluffbody trailing edge in a socalled “closecoupledâ€‌ configuration. Nonreacting and reacting simulations of the Georgia Tech single flameholder test rig [Cross et al., 2010, “Dynamics of Nonpremixed Bluff BodyStabilized Flames in Heated Air Flow,â€‌ Proceedings of ASME Turbo Expo, Paper No. GT201023059] are conducted using an Eulerian–Lagrangian approach with a finite volume solver. Experimental data is first used to characterize the boundary conditions under nonreacting conditions before simulating reacting test cases at two different fuel mass flow rates. The two fuel mass flow rates not only result in different global equivalence ratios but different spatial distributions of fuel, especially in the nearfield wake of the bluff body. The differing spatial distribution of fuel results in two distinct flame dynamics; at the highfuel flow rate, largescale sinusoidal Bأ©rnard/vonKأ،rmأ،n (BVK) oscillations are observed, whereas a symmetric flame is seen under the lowfuel flow rate condition.