Diesel engine, fuel combustion method for diesel engine and method for designing a diesel engine

摘要

A diesel engine is provided, in which fuel is injected toward a lip portion 11 of a reentrant-type cavity 8. Fuel spray 15 reaches the lip portion 11 in the ignition lag time and forms fuel vapor 16 near the lip portion 11. With the expansive flow of the combustion gas 17 caused by the ignition, the fuel vapor 16 in front of the ignition position hits the surrounding wall of the cavity 8 and is guided toward the bottom of the cavity 8, promoting a vertical vortex. Thus, heat spots do not become large at a certain site and are extinguished quickly. The generation of NO is suppressed, while the vertical vortex promotes the after-burning of soot in the combustion gas 17.