Numerical simulation of fuel dribbling and nozzle wall wetting

The present work describes a numerical methodology and its experimental validation of the flow development inside outside orifices during pilot injection, dwelt time subsequent start injection cycle. compressible Navier-Stokes equations are numerically solved in six-hole injector imposing realistic conditions needle valve movement considering addition time-dependent eccentric motion. motion is simulated using immersed boundary method; this allows for simulations to be performed at zero lift between successive injections, where remains closed. Moreover, model utilises fully two-phase (liquid, vapour) two-component (fuel, air) barotropic model. air’s with an additional transport equation coupled VOF interface capturing method able resolve near-nozzle atomisation resulting impact injected liquid on oleophilic nozzle wall surfaces. found responsible formation strong swirling flows orifices, which not only contributes breakup jet into ligaments but also their backwards towards external surface injector. Model predictions suggest that such wetting phenomena more pronounced closing period re-opening nozzle, due residual gases trapped contribute poor fluid upon events.