Mixing in Wall-Jets in a Heavy-Duty Diesel Engine: A LES Study
The paper presents a large eddy simulation investigation on the effect of fuel injection pressure on mixing, in an optical heavy-duty diesel engine. Recent investigation on impinging wall jets at constant-volume and quiescent conditions exhibited augmented air entrainment in wall jets with increasing injection pressure, when compared with a free jet. The increased mixing rates were explained as owing to enhanced turbulence and vortex formation in the jet-tip in the recirculation zone. A recent investigation carried out in an optical heavy-duty diesel engine indicated however a negligible effect of injection pressure on the mixing in the engine environment. The effect of enhanced turbulence and vortex formation of the jet-tip in the recirculation zone is believed weaker than the effect of engine confinement, due to the presence of fuel from adjacent jets limiting the mixing the fuel with the ambient gas.