On the Propagation of Turbulent Jet-Flame in a Closed Vessel

In the stratified charge engine with an auxiliary chamber, the time required for combustion in the main chamber is considered to depend upon the characteristics of the turbulent jet-flame propagating in it. This study has been conducted to explore the controllability of the time required for combustion by changing the characteristics of the turbulent jet-flame. Experiments were performed by using a constant volume combustion chamber which was divided into a primary and a secondary chamber by an orifice plate. The characteristics of the turbulent jet-flame were changed by changing fuel, mixture strength and hole size of the orifice plate.

The experimental results indicate that the time τ required for combustion in the secondary chamber mainly depends upon the jet-flame velocity V_F (propagation velocity of the leading front of the jet-flame) and the mixture strength Φ. It is shown that a unique relation exists between V_F and (τ S_L)⁻¹, were S_L is the laminar burning velocity of the mixture, except for rich mixtures of propane-air and n-butane-air.