A numerical study on the effect of cavitation erosion in a Diesel injector

The consequences of geometry alterations in a Diesel injector caused by cavitation erosion are inves-tigated with numerical simulations. The differences in the results between the nominal design geometryand the eroded one are analyzed for the internal injector flow and spray formation. The flow in the in-jector is modeled with a 3–phase Eulerian approach using a compressible pressure–based multiphase flowsolver. Cavitation is simulated with a non–equilibrium mass transfer rate model based on the simplifiedform of the Rayleigh–Plesset equation. Slip velocity between the liquid–vapor mixture and the air isincluded in the model by solving two separate momentum conservation equations. The eroded injector isfound to result to a loss in the rate of injection but also lower cavitation volume fraction inside the nozzle.The injected sprays are then simulated with a Lagrangian method considering as initial conditions thepredicted flow characteristics at the exit of the nozzle. The obtained results show wider spray dispersionfor the eroded injector and shorter spray tip penetration