Coupled 1D-3D Simulation of Common Rail Injector Flow Using AVL HYDSIM and FIRE

The paper describes a 1D-3D modeling technique for the simulation of the fuel injection systems. The technique is based on the one-dimensional modeling of the fuel flow and the mechanical motion of the injection system with the AVL software HYDSIM (from e.g. the fuel rail up to the nozzle chamber) and three-dimensional modeling of the nozzle flow with AVL-FIRE (from the needle seat through the spray holes up to the combustion chamber). The nozzle mesh, including the nozzle sac region with spray holes and (optionally) the lower part of the nozzle chamber, is created with the FIRE Preprocessor. The interface between the 1D and the 3D simulation regions can be freely chosen within the nozzle chamber at any position between the needle seat and guide.