Study of Two Phase Flow Inside GDI Injectors
The flow inside high pressure swirl injector has been simulated in two different ways. First, the two-dimensional axisymmetric Navier-Stokes equations coupled with the Volume-of-Fluid (VOF) method were employed for simulation of the formation mechanism of the liquid film inside the swirl chamber and the orifice hole of the pressure swirl atomizer. Second by using One Dimensional simulation approach the single phase flow inside GDI has been simulated by considering air cavity as a wall and two important characteristics of the flow has been calculated, discharge coefficient and cone angle. To validate both, the results for base injector were compared in the steady state operation with those of available experiments in the literature. In four different horizontal slices the mean values of swirl velocity, axial velocity and mean pressure has been compared. The cost and benefits are two approaches has been examined Through extensive simulations.
Keywords- GDI Injector, Volume of Fluid, One Dimensional Model, Spray Cone Angle, Discharge Coefficient