Combined effects of combustion chamber geometry and injection strategy on combustion and emissions of a diesel engine

Abstract

For a certain type of direct injection diesel engine, a three-dimensional model of a single-cylinder complete combustion chamber and in-take/exhaust port was established. Three-dimensional Computational Fluid Dynamics (CFD) analysis software CONVERGE was used for simulation. The effects of fuel injection strategy and combustion chamber geometry on combustion emissions of diesel engine were studied while the combustion chamber volume, engine compression ratio, total fuel injection quantity and total injection duration were kept unchanged. The results show that the strategy of multiple injection and reasonable shape of combustion chamber can effectively increase the turbulent kinetic energy in cylinder, improve the uniformity of oil-gas mixing, reduce the emission of pollutants, and increase the quality of after injection can further reduce the emissions of NOx and soot.