Energy & Fuels, Vol.33, No.4, 3565-3575, 2019
Application of an Equilibrium-Phase Spray Model to Multicomponent Gasoline Direct Injection
An equilibrium-phase (EP) spray model for simulating high-pressure diesel fuel injection has recently been proposed, which is based on a local phase equilibrium assumption and jet theory. In this model, spray vaporization is assumed to be a mixing-controlled equilibrium process, while the nonequilibrium processes of droplet breakup, collision, and surface vaporization are neglected. The model shows a good grid independency by introducing a liquid-jet model and a gas-jet model. In this study, the EP model is applied in simulations of multihole gasoline direct injection (GDI). The model validation is performed for two different GDI injectors, that is, the Engine Combustion Network Spray G injector and a GM injector, operated at ambient temperatures from 400 to 900 K and ambient densities from 3 to 9 kg/m(3), with the fuel isooctane. Good agreement is found between simulation and available experimental data in terms of liquid/vapor penetrations, shape of the vapor envelope, and the axial velocity evolution along the injector centerline for no or slight spray collapse conditions. In addition, a 10-component gasoline surrogate fuel is employed to demonstrate the capability of this model to simulate a multicomponent spray. The results reveal considerable dependency of vapor distribution on fuel properties and ambient temperature, which is essential for predictions of engine combustion and emissions.