Investigation of Spray-Bowl Interaction Using Two-Part Analysis in a Direct-Injection Diesel Engine 2010-01-0182

The purpose of this study is to investigate the effect of spray-bowl interaction on combustion, and pollutants formation at one specific high-load point of a single-cylinder small-bore diesel engine through computational analysis. The simulations are performed using Representative Interactive Flamelet (RIF) model with detailed chemical kinetics. Detailed chemistry-based soot model is used for the prediction of soot emissions. The simulations are performed for five different injection timings. Model-predicted cylinder pressure and exhaust emissions are validated against the measured data for all the injection timings. A new method - Two-part analysis - is then applied to investigate the spray-bowl interaction. Two-part analysis splits the volume of the combustion chamber into two, namely the piston bowl and the squish volume. Through analysis, among others the histories of soot, carbon monoxide (CO) and nitric oxide (NO

) emissions inside both volumes are shown. The results show that soot and CO emissions in the exhaust are mainly originated from the piston bowl volume. In case of NO

emissions, both volumes add to net NO

emissions, but the higher amount of NO

comes from the piston bowl volume.