Karman 와류 흘림과 층류 예혼합화염의 상호작용

Flame oscillation and self-induced noise via interaction with a Karman vortex street have been investigated using a slot burner. The wrinkled flame surface showed the same pattern and frequency to those produced by Karman vortex street at the downstream of a circular cylinder. The measured flame oscillation frequency is very similar to the twice of estimated Karman vortex shedding frequency with Strouhal number of 0.2. This result could be a clear evidence of the interaction between laminar pre-mixed flame and a Karman vortex street. As Reynolds number increases with the increase of cylinder diameter from 1.67 ㎜ to 3.01 ㎜, the measured. oscillation frequency decreases from 334 ㎐ down to 175 ㎐ and the self-induced noise level increases from 64 ㏈ to 68 ㏈. The flame is more severely wrinkled with 3.01 ㎜ cylinder. The increased sound level and more severly wrinkled flame suggest that the flame/vortex interaction becomes more intense with the increase of Reynolds number.