Numerical Investigation of Influence of injector nozzle geometry on Formation of Direct Injection Gaseous Fuel Jet in a Constant Volume Chamber

The development of a direct injection natural gas engines has been undertaken to improve the engine performance of a spark ignited CNG fuelled engine. Design of injector is the most important challenge for development of gaseous direct injection engines. In this article the effect of injector nozzle geometry on the mixing and penetration of gaseous fuel (CNG) and air downstream of the nozzle will be investigated. The fuel distribution in the constant volume chamber for different nozzle geometries including cylindrical and converging nozzles with different diameters and different injection pressures will be determined with CFD simulations. The design of injector in this project will be performed for spray guided direct injection CNG fueled SI engines and the focus will be on the stratified method of mixture preparation. The model results were shown to be in a reasonable agreement with experimental results when the penetration of jet was compared with the previous experimental investigations.

Keywords:

injector , injector nozzle , CNG direct injection , engine , mixture formation