Three-Dimensional Modeling of Horseshoe Vortex Flows

AVCO Lycoming’s circumferentially stirred combustor employs a well-established vortex, in the shape of a horseshoe with fuel injection at the apex, to promote mixing in each sector of the annulus. This paper presents the results of a three-dimensional viscous flow analysis of this horseshoe vortex flow field. The results agree well with flow visualization tests. Analytical results were also obtained for some variations of the basic configuration in which the horseshoe vortex fails to become well-established. These results highlight certain critical aspects of circumferentially stirred combustor designs. Thus the overall study has illustrated the substantial engineering contribution that can be made by three-dimensional modeling of the underlying flow fields in combustors employing highly structured, swirling flows.