Numerical Investigation of Multiple-Injection Strategies of Methanol in a DICI HD Optical Engine
Methanol fuel is a genuine candidate on the alternative fuel market for internal combustion engines within heavy-duty transportation sector. The thermo-physical properties of methanol allow to achieve high thermodynamic efficiency and low emission levels with a good margin below the EURO VI standard using compression ignition (CI) engines with advanced injection strategies. However, due to a low stoichiometric air/fuel ratio and a high latent heat of vaporization there are two challenges that can be mentioned; (a) the tendency to a high pressure rise rate due to the rapid chemical kinetic driven ignition process and, (b) the required high inlet temperature to initiate compression ignition event. These challenges can be tackled for instance by employing multiple-injection strategies, which reduces both the maximal pressure rise rate and the demand on the high inlet temperature.