摘要：The combustion process of diesel engine directlyaffects the whole power output, fuel consumption andemissions level. The in-cylinder air motion, mixture forma-tion and combustion process is closely related with theintake and exhaust ports, valves and combustion chambershape [1, 2]. The in-cylinder turbulence and eddy motionalso depend upon the intake port geometry and combustionchamber profile [3, 4]. Therefore, the trapped mass duringthe intake stroke is an important index that measures theentire engine performance. Besides the challenge of in-creasingly stringent emissions regulations, modern low-emission diesel engine designers still keep high thermalefficiency of engine as a goal. However, the key is how toachieve exact match of the high-pressure fuel injection andin-cylinder swirl intensity. As fuel injector is porous andinjection pressure higher, a relatively lower swirl levelenough to make the fuel spray mix well with air charge.This shows that the in-depth study of the relationship be-tween intake port geometry and its performance is signifi-cantly crucial.
