Technical Paper
Simulation of a Diesel Jet Assumed Fully Atomized at the Nozzle Exit
1998-02-23
981067
The KIVA-II code is probably the most advanced CFD code for simulating diesel engine fuel spray, but the atomization sub model remains imperfect. For this reason, several break-up models exist in published literature. The poor physical understanding of liquid break-up prevents it from being modeled faithfully. In our 1997 SAE Paper, a new approach was proposed, based on a jet fully atomized when leaving the nozzle. It avoids the break-up description by fixing some fictional initial conditions for droplet velocity, average diameter and size distribution. The originality lies in the choice of droplet injection velocity. The proposed initial velocity is roughly twice that normally used, i.e. the value found using the Bernoulli equation with a discharge coefficient of around 0.75.
