**2. Materials and Methods**

The Wärtsilä 6L 46 is a four-stroke marine diesel engine, turbocharged and intercooled with direct fuel injection. It has 6 in-line cylinders and each cylinder has 2 inlet and 2 exhaust valves. The standard engine employed in the present work does not implement any NOx reduction system such as water injection, EGR, SCR, etc. It incorporates a fast and e fficient turbocharging system called single pipe exhaust (SPEX). The cooling system is split into high-temperature and low-temperature stages. Other specifications are provided in Table 1.


**Table 1.** Characteristics of the engine at 100% load.

A CFD analysis previously validated with experimental results [28–34] was carried out using the open software OpenFOAM. The simulation was based on the equations of conservation of mass, momentum, and energy and the numerical details are listed in Table 2.


**Table 2.** Numerical details.

A comparison between the numerical and experimental results is illustrated in Figure 1 and Figure 2. Figure 1 shows the emissions and SFC obtained numerically and experimentally at several loads, and Figure 2 shows the in-cylinder pressure and heat release rate obtained numerically and experimentally at 100% load. As can be seen, both figures show a reasonable correspondence between numerical and experimental results.

**Figure 1.** Specific fuel consumption (SFC) and emissions numerically and experimentally obtained at di fferent loads.

**Figure 2.** In-cylinder pressure numerically and experimentally obtained at 100% load.
