Reacting Flow Over a Non-Traditional Flame Stabilizer

Abstract

The flow dynamics and flame configurations of a ν-shaped flame holder with a slit have been investigated with LDA, a fine-wire thermocouple, a gas analyzer, and a high-speed video camera. The main objectives were to explore the dominant mechanism of the stabilized wake flames and the structural alterations of the wake flow under the influence of the diverted jet

The experimental results show that the flow patterns and flame structures of the slit ν-gutters were determined by interactions between the diverted jet and the recirculated vortices. The slit ν-gutter brought about jet-dominated wake flames, whereas the wake flames of a regular ν-gutter were generally unsteady and shrank periodically into a small heart-shaped flame kernel. Because of the effect of the diverted jet, the slit ν-gutters generated several maxima of turbulence intensity and a greater fuel concentration in the core region of the near-wake. The roll-up of the wake flame behind the ν-gutter with a 2-mm slit was significantly suppressed by the effect of both the diverted jet flame and the jet-induced recirculated vortex. Hence, the wake flames became more stable than the traditional one. As the slit width was further increased to 4 mm, the wake flames became unstable and were typically locally quenched because of the larger velocity of the penetrating jet and the small turbulence intensity in the near wake.

Key words:

• Stabilizer
• diverted Jet
• recirculated vortex
• wake flame