Recent Developments in Swiri Induced Turbulent Mixing for 4-Stroke Cycle Engines

To meet both environmental standards and improved fuel economy emphasis is being stressed on lean-burn technology. An important goal of that technology is to improve the homogeneity of the fuel/gas charge. Swirl flow has been suggested as a possible solution. However, the stable nature of single vortex swirl has not provided the desired mixing but rather tends toward stratification. Blade induced swirl systems are examined and shown to be very effective when multi-swirl vortices of counter-rotation are produced. With net zero angular momentum these vortices merge rapidly and self-destruct with intense mixing. Since multi-swirl mixing can have near zero residual swirl high heat transfer losses are also minimized. Experimental lean-burn limits approach 22 to 1 A/F ratio.