Abstract
This paper presents simulations of Diesel spray atomisation, obtained by a quasi-direct CFD method which employs a combination of Large-Eddy-Simulation (LES) to calculate the turbulence and a Volume of Fluid (VOF) technique to track the gas-liquid interface. The simulations are for an idealised injector nozzle with both short (LID = 5) and long (LID > 40) holes, with the results for the latter taken, for comparison purposes, from a previous study. It is found that the short nozzle produces more rapid atomisation, leading to shorter jet breakup length, larger spray angle and smaller droplet sizes, all of which are in reasonable correspondence with experimental observations. The difference in the performance of the two geometries is explained in terms of the nozzle-generated turbulence and its initial perturbation of the jet surface, which are more intense for the short-hole case.
