Study on the near-wake flow behind EBMC flameholder

The detailed near-wake flow behind the Edge Blowing Mixture Curtain flameholder (EBMC flameholder) and the V-gutter flameholder were investigated by using 2D cross-correlation on-line PIV in a low speed wind tunnel. Experiments were conducted at the main flow velocity of 10m/s and 20m/s, the jet velocity of 10m/s and 20m/s respectively. Results show that near-wake flow structure of both flameholders is governed mainly by large-scale vortices in the form of vortex street, and the jet increases the size of the vortices. But symmetrical large-scale vortices appear when the momentum ratio of the jet to the main flow is high, which is disadvantage to combustion. Based on the research on the instantaneous flow, the instantaneous viewpoint of the flame stability mechanism was brought forward. Important effect of alternate formation and shedding of vortices on the flame stability was discussed. All of these offer important theoretic basis for further studying combustion performance of the novel flameholder.