2012 Volume 54 Issue 169 Pages 139-146
Using the detailed numerical simulation approach, the physical mechanisms of spray primary atomization and early group combustion formation are investigated. The grid resolution is made fine enough to capture the final droplet generation by surface tension. In the cold flow simulation of liquid jet primary atomization, the injected liquid is subject to the interaction with the gas phase and atomization occurs both from the jet head umbrella edge and from the liquid core surface. Ligaments are first created, and droplets are finally generated from these ligaments. The interface instability development mechanism and droplet generation mechanism can be physically explained in detail by the simulation results. In the evaporating/reacting simulation, the early stage fuel vapor clustering is captured. The interaction between droplets determines the clustering formation process. In the jet head recirculation region where the droplet number density is relatively high, group combustion is expected to occur when ignition finally starts.
