Applicability of LP Gas Jet to MPI System

Abstract

This paper deals with LPG and CNG jets, which will be used for gas fuel supply system of automobile engine. Variation of tip penetration and vortex radius at the front of jets with injection time of the fuel are numerically calculated with a modified transient jet model based on original WITZE's model. Following conclusions were derived : (1) No significant difference was found in the variation of the tip penetration of fuel jet between LPG and CNG jets. (2) Growing speed of the front vortex of the LPG jet is slightly slower than that of the CNG jet. (3) When the same amount of LPG or CNG fuel is injected into a fuel supply tube, the more the number of injection holes is and the less of each injection hole radius is, the penetration of the jet and the radius of front vortex are decreased. The tip penetration is decreased with decrease in injection pressure.