Experimental Study on the Effect of Velocity gradient on Propagation speed of Ttribrachial flame in Laminar Coflow Jets

삼지화염의 전파속도에 대한 속도구배의 영향에 관한 실험적 연구

The tribrachial flame in laminar coflow jet has been investigated experimentally with unsteady propagating condition. In this experiment, we found that the tribrachial point has an angle of flame surface because the location of tribrachial point is not on the base point of flame but on the inclined surface of flame. This angle of Flame surface at tribrachial point are increasing when the flame is approaching to the nozzle exit. With considering this angle of flame surface, the radial velocity gradient can affect flame propagation speed by increasing flow-stretch effect. The propagation speed of tribrachial flame was calculated with including above stretch effect. The speed decreases with increasing velocity gradient due to the increment of stretch effect.