JET MIXING IN A MODEL DIRECT-INJECTION DIESEL-ENGINE WITH SWIRL

Computational and experimental results are reported of an investigatio n into jet mixing, using the hydraulic analogue technique to simulate the diesel injection process. Steady state and impulsive injections in to both quiescent and swirling flow fields are considered. A compariso n between predictions and experimental results shows a deficiency in t he turbulence model's capability to predict recirculation zones downst ream of the point of injection. The relative effect of swirl on jet pe netration is examined and it is argued that a non-uniform injection ch aracteristic leads to a more rapid formation of a combustible mixture, thereby reducing the ignition delay period and the pressure gradient during combustion.