Influence of Injection Angle and Valve Opening Manner on Mixing Performance in a Large Bore Port Fuel Injection Compressed Natural Gas Fueled Engine

Abstract

One new kind of gas injection devices (GIDs), with movingcoil electromagnetic linear actuator (MCELA) and mushroomtype poppet valve, was projected to inject sufficient compressed natural gas (CNG) to a largebore port fuel injection (PFI) engine. It had larger mass flow rate and better controllability than conventional GID. And the transient computational fluid dynamics (CFD) engine model incorporating the GID's motion was established to analyze the effects of the GID injection angle and poppet valve opening manner on the mixing homogeneity in the intake port, and finally, the incylinder mixing performance and gas movement intensity were compared. The results indicate that with the increasing of injection angle, the mixing homogeneity in the nearfield injection location of intake port will be better, and the time when fuel starts to get into cylinder will be later. At ignition time, the injection angles 60 deg, 90 deg, and 120 deg show better incylinder mixing performance, while 150 deg has the worst. The pullopen GID injects more momentum to the intake port than the pushopen one, and the mixing degree both in the intake port and cylinder is higher.