The Influence of the Flame Structure on the Combustion Oscillations in a Cylindrical Chamber

Experimental aspects of soot presence in pulsating diffusion flame

“…Yoshida et al (2001) have studied the presence of an acoustic field in turbulent jet diffusion flames, and they observed that at the resonant conditions the transient from laminar to turbulent flow is enhanced, and consequently the turbulent intensity of the flow increases markedly. But the long predominantly diffusive flames are normally not able to auto-excite acoustically the confined combustion, neither to amplify the oscillations in the case of external actuation, as presented by Ferreira et al (2006). However, a previous work of Ferreira et al (2005) shows that flames predominantly diffusive are more susceptible than premixed flames to strong changes in the combustion gases composition when an external acoustic field is applied.…”

“…But the long predominantly diffusive flames are normally not able to auto-excite acoustically the confined combustion, neither to amplify the oscillations in the case of external actuation, as presented by Ferreira et al (2006). However, a previous work of Ferreira et al (2005) shows that flames predominantly diffusive are more susceptible than premixed flames to strong changes in the combustion gases composition when an external acoustic field is applied. When the acoustic oscillation is applied to an originally diffusion flame, the traditional structure of this kind of flame changes to look like a predominant premixed flame, with large quantities of oxygen into the jet fuel side, as the results presented by Rocha et al (2006).…”