A Coupled Tabulated Kinetics and Flame Propagation Model for the Simulation of Fumigated Medium Speed Dual-Fuel Engines 2019-24-0098
The present work describes the numerical modeling of medium-speed marine engines, operating under a fumigated dual-fuel concept, i.e. with the second fuel injected in the ports. Due to the need to reduce engine-out emissions while maintaining engine efficiency, manufacturers are investigating new engine technologies. In the maritime industry, a promising technology to achieve these goals is that of fumigated dual-fuel engines, allowing a large amount of diesel to be replaced by a premixed fuel. To fully optimize the operational parameters of such a large maritime engine, computational fluid dynamics can be very helpful. Accurately describing the combustion process in such an engine is key, as the prediction of the heat release and the pollutant formation is crucial. Auto-ignition of the diesel fuel needs to be captured, followed by the combustion and flame propagation of the premixed fuel. In this work, an approach based on tabulated kinetics has been used, to include detailed chemistry while still maintaining acceptable computation times. To allow for the modeling of a fumigated dual-fuel engine, it has been extending with a Coherent Flame Model (CFM), capable of tracking the premixed flame surface. This methodology has been validated for standard diesel operation, dual-fuel diesel/natural gas and diesel/methanol operation. The model has been applied under a variety of different loads, speeds, diesel substitution ratio’s and equivalence ratio’s to capture and study a large operating range. A comparison between experimental and numerical data has been performed.
Gilles Decan, Tommaso Lucchini, Gianluca D'Errico, Sebastian Verhelst
Ghent University, Politecnico di Milano, Lund University
14th International Conference on Engines & Vehicles