Numerical Simulation on Spray Characteristics in Direct Injection Gasoline Engine

In this paper, a simulation model was built for in cylinder stratified charged and lean combustion GDI engine, and the spray model was validated. Based on this, numerical simulation of mixture stratified combustion was performed in a gasoline direct injection (GDI) engine with AVL FIRE. The effects of different injection timings on the mixture quality near the spark plug were analyzed and the results showed that injection timings would significantly influence the fuel stratification pattern and the combustion characteristics. Improper injection timings would make the mixture too lean or too rich near the spark plug, resulting in a poor combustion. For a GDI engine, injection timing will play an important role in the success of stratified combustion.