Effects of injector parameters on mixture formation for multi-hole nozzles in a spray-guided gasoline di engine

摘要: This paper focuses on ways of improving the spray formation from spray-guided multi-hole gasoline direct injection injectors. Work has been done both experimentally using laser diagnostic tools and numerically Computational Fluid Dynamics. Laser Induced Exciplex Fluorescence (LIEF) measurements in a constant pressure chamber optical engine have shown that injectors with 6-hole nozzles 50-degree umbrella angles are unsuitable for stratified combustion because they produce steep air-fuel ratio gradients create overly-deep liquid fuel penetration as well presence around spark plug. In order to study injector performance, numerical calculations AVL FIRE™ CFD code were performed. The results indicate by increasing angle, extent piston wall wetting can be decreased. Also, changing pattern holes nozzle changes pattern, enabling its optimization respect ignition flame propagation. Furthermore, PDA Direct Imaging experiments showed l/d reducing hole diameter resulted decrease mean droplet sizes (D32). angle was found increase decreasing ratios. It also choosing suitable it is possible control local AFR cross-flow velocity at Copyright © 2005 SAE International.