Effect of Injector Nozzle Design on Spray Characteristics for Hydrogen Direct Injection Engine Conditions

Hydrogen has a unique flammability property compared to other fuels. Previous researches proved that direct injection is the most suitable method for this particular fuel. This research aims to study the effect of injector nozzle geometry on mixture and internal combustion efficiency in four stroke automotive engine which operates using hydrogen fuel. The research will concentrate on two aspects, namely the inflow and outflow profile of the injector nozzle. For each flow profile, the effect of geometrical design of the nozzle on the parameter such as flow velocity, fuel penetration distance, average mass fuel consumption and diffusion will be studied in detail. In this study, numerical simulation analysis was done by using the computing fluid dynamics (CFD) software, Star-CCM+. Models comprise of multiple orifice nozzle geometry with single angle orifice and double angle orifice was developed with CAD software. A suitable design for a better mixing nozzle would then be determined. Nozzle which possesses a high number of orifice and a smaller diameter will result in a higher flow velocity in the cavity nozzle channel. Geometry of nozzle with different angle of orifice was found to be the most suitable due to the low flow penetration distance and fuel consumption as well as combustion enhancement by the diffusion rate.