Investigation of Multi-Hole Impinging Jet High Pressure Spray Characteristics under Gasoline Engine-Like Conditions

Impingement of jet-to-jet has been found to give improved spray penetration characteristics and higher vaporization rates when compared to multi-hole outwardly injecting fuel injectors which are commonly used in the gasoline engine. The current work studies a non-reacting spray by using a 5-hole impinging-jet style direct-injection injector. The jet-to-jet collision induced by the inwardly opening nozzles of the multi-hole injector produces rapid and short jet breakup which is fundamentally different from how conventional fuel injectors operate. A non-reacting spray study is performed using a 5-hole impinging jet injector and a traditional 6-hole Bosch Hochdruck-Einspritzventil (HDEV)-5 gasoline direct-injection (GDI) injector with gasoline as a fuel injected at 172 bar pressure with ambient temperature of 653 K and 490 K and ambient pressure of 37.4 bar and 12.4 bar. The engine-like thermodynamic conditions were generated in a constant-volume high pressure-temperature preburn type combustion vessel for the two corresponding SI engine conditions. In addition, Computational fluid dynamics (CFD) work has been performed using an Eulerian-Lagrangian modelling approach. Iso-octane was used as a fuel in simulation for both injectors. Experimentally validated simulations provided detailed information about spray structure and spray related phenomena like atomization, vaporization, and fuel mass distribution. It was found that the 5-hole impinging jet injector shows better vaporization, has longer vapor penetration than traditional GDI injector.