Detached Eddy Simulation of High Pressure Diesel Injectors

The internal flows of high pressure diesel injectors are simulated numerically in order to investigate the complex transient flow structures and the unsteady forces imparted to the injector needle that result. The gas-liquid two phase flow is modeled using a mixture schematic with the cavitation numerically modeled using the Zwart-Gerber-Belamri model. Both the k-ε model and the detached eddy simulation (DES) model are used and the numerical results are compared. Our study shows that the DES model is able to capture the important unsteady flow features missed by the k-ε model. Our simulation also shows that the injector geometry, specifically the gain orifice, plays an important role in the forces developed on the injector needle.