Investigation of Gasoline Compression Ignition in a Heavy-Duty Diesel Engine Using Computational Fluid Dynamics

A computational fluid dynamics (CFD) model was developed to explore gasoline compression ignition (GCI) combustion. Results were validated with single-cylinder engine (SCE) experiments. It was shown that the CFD model captured experimental results well. Cylinder pressure, heat release and emissions from the CFD model were also used to analyze the performance of GCI combustion with a current heavy-duty diesel engine platform. This work also provides detailed analysis on in-cylinder combustion and emissions using CFD. It was found that multiple injection strategy can deliver desirable fuel stratification profile that benefits both engine and emissions performance. A wave contoured piston was compared with a stepped-lip type piston for both GCI and Diesel combustion scenarios on the same engine platform. Stepped-lip pistons offer an opportunity to use multiple injection strategies to overcome high UHC emissions of GCI combustion when compared to wave pistons. On the other hand, wave pistons, offer more mixing enhanced combustion in traditional diesel combustion systems. Emphasis on these different combustion concepts show that simultaneous optimization of engine and fuel property could really overcome the efficiency and emissions trade-off that conventional diesel combustion performance has been known for.