Large eddy simulation of non-reacting flow and mixing fields in a rotating detonation engine

Abstract

Large Eddy Simulations (LES) of the non-reacting flow and mixing fields in a Rotating Detonation Engine (RDE) from Air Force Research Laboratory (AFRL) are performed. Effects of the total number of fuel injection orifices and air flow rates on the mixing in the AFRL RDE are studied using a periodic burner sector with five injection orifices. The instantaneous vortex structures and shock wave in the non-reactive AFRL RDE are identified, and the structures are found to be similar to those in jet in crossflow. Also, the compositional non-uniformity in the height and azimuthal directions of the burner is observed. The mixing efficiency, root-mean-square value of the hydrogen mass fraction and mixing area ratios are introduced to quantify the mixing process. The observations from LES qualitatively justify the behaviors of detonation fronts observed in the experiments. Finally, results based on full scale AFRL RDE are briefly discussed.