Probing into the Effects of Fuel Injection Pressure and Nozzle Hole Diameter on Spray Characteristics under Ultra-high Injection Pressures Using Advanced Breakup Model

Abstract

In this article, non-evaporating and non-reacting diesel spray is modeled under ultra-high injection pressure using an Eulerian-Lagrangian scheme. This is accomplished in order to probe into the effects of injection pressure, nozzle diameter, and ambient density on spray characteristics. An advanced hybrid breakup model that takes into consideration the transient processes during spray injection has been added to the open source code OpenFOAM. Reynolds-Average Navier-Stokes (RANS) equations are solved using standard turbulence model and fuel droplet is tracked by a Lagrangian scheme. Published experimental data have been used for validation of spray characteristics at 15 kg/m3 ambient density and injection pressures of 100, 200 and 300MPa. Also, three nozzle diameters of 0.08, 0.12 and 0.16mm have been implemented for investigating the effect of this parameter on spray formation. Computed spray shape, jet penetration, spray volume, equivalent ratio along the injector axis and Sauter Mean Diameter (SMD) illustrate good agreement with experimental data of single hole nozzle and symmetric spray. The effects of fuel injection pressure, nozzle hole diameter and ambient density on main spray parameters are presented. It is concluded that numerical model presented here is quite suitable for accurately predicting diesel spray shapes under ultra-high injection pressures.