Possibilities of Diesel Exhaust Purification by the Aid of Induction Swirl.

Abstract

The effect of induction swirl on the combustion of a D. I. diesel engine with deep bowl chamber was studied for both standard and retarded fuel injection timings by the analysis of exhaust gas and engine output characteristics as well as the composition distribution of burnt gas along the exhaust procedure. As a result, the following was revealed: The burning characteristics of the engine are principally controlled by the swirl velocity. The optimum swirl velocity for combustion increases with retarding of the fuel injection timing. Under the optimum swirl velocity, the distribution patterns of fuel and burnt products in the cylinder hardly change irrespective of a remarkable change in the fuel injection timing. This assures that without any increase in soot and imperfect combustion products, a significant reduction of the exhaust Nox is possible, provided that the swirl velocity is optimized for the retarded phase of the burning period.