Two-Zone Model for Calculation of Nitrogen-Oxide Formation in Direct-Injection Diesel Engines

A quasi-dimensional, two-zone combustion model was developed for calculating the formation of nitrogen oxides in direct-injection diesel engines. The model was verified by means of measurements obtained with two direct-injection, four-stroke, single-cylinder diesel engines, one of which had a total displacement of 3.96 liters and the other 5.95 liters. The combustion model was used to analyze the thermal dynamics and reaction kinetics of the procedures involved in well-known methods for the engine-internal minimization of nitrogen oxides.