Experimental investigation of vortical motions in a 2D scaled experimental motor

The detail motions of vortices in a 2D scaled motor of SRM were studied by high speed visualization in this paper. The experimental data indicate that the flow start to separate right after the backward-facing step, which gives birth to periodically-shedding vortices. The scale of vortex increases with their convection downstream along the mean flow. Vortex breaks down due to its impingement on the submerged nozzle head, part of which exits in the motor directly through the nozzle throat while the other part flows into the cavity formed by submerged nozzle. Few of the vortices flow directly into the submerged nozzle cavity without impinging on the submerged nozzle head. The results obtained in this paper could improve the understanding of the flow in SRM and provide experimental validation for numerical simulation.