Search Results

The disk-type gasoline injector uses a flat disk with a seal ring to control the valve opening and the flow rate. Though the disk-type injectors provide several advantages over the pintle-type injectors, some disk injector drips and produces undesired large droplets after several minutes of operation. High-speed photography shows that the injector dripping problem could be a result of slow droplets coming out of the injector at the end of the injection cycle. Namely, a second slow spray is generated. Purpose of this work is to employ the Computational Fluid Dynamics (CFD) techniques to identify the causes of the slow droplets and to improve the injector design. The CFD analysis thus focuses only on the closing stage of the injection cycle. The computational domain in the valve decreases with the time; the transient grid sizes and locations are determined by a constant valve closing velocity.