A Preliminary Numerical Study of a Medium Speed Marine Engine Fueled by Methanol

The work presents a study of a marine four-stroke medium speed engine fueled by methanol. This study arises from the current interest in developing marine engines with alternative fuels, such as methanol, verifying performance and polluting emissions, in particular CO
2
which also represents a cause of concern in the naval sector. Methanol is considered as a renewable energy source which features some better physicochemical properties compared to the traditional fossil fuels. In fact, methanol has higher laminar flame speed and wide lean-burn limitation, potentially reducing nitrogen oxides, carbon monoxide and unburned hydrocarbon emissions with a higher combustion efficiency. The used approach is based initially on a zero-dimensional model developed in Matlab©-Simulink© language and subsequently on a one-dimensional model through a commercial code that allows the entire engine to be simulated. The results provide the initial conditions for an in-cylinder CFD calculation, via the ANSYS FORTE® code, to study combustion in detail using an alternative fuel such as methanol and introducing adequate kinetic mechanisms. The obtained outcomes are compared with data referring to the same engine fueled by natural gas, available in the engine project guide.