Reacting and Nonreacting Flowfields of a V-Gutter Stabilized Flame

Abstract

Particle image velocimetry measurements have been performed to determine the flowfield around a confined V-gutter bluff body in both nonreacting and reacting environments. The incoming flow to the V-gutter bluff body is a vitiated mixture with secondary liquid fuel being injected upstream through a fuel spray bar to mimic realistic conditions. The measurements capture instantaneous and mean flow structures formed in the wake region of a three-dimensional bluff body. In addition to the flow structures, the mean velocity components, mean out-of-plane vorticity, and the turbulent kinetic energy have been compared between the nonreacting and reacting test cases. The results show significant differences in the instantaneous flow structures. The nonreacting case results in asymmetric shedding of large-scale vortical structures which span the entire wake region, whereas the reacting case results in both symmetric and asymmetric shedding of smaller scale vortical structures which are flattened out within the shear layer. A comparison of the mean velocity components clearly shows that the reacting case results in a larger region of reversed flow, experiences an acceleration of the freestream flow due to combustion, and results in a slower dissipation of the wake region.