323 
324 
325 
326 
327 
328 
329 
LF = Pactual — (Yactuat 
Panax Umax 
(0) 
where n is 3. The Ugeruat and Umax are known and correspond to the average ship speed derived 
from AIS data, for the period when each ship passes close to the MS, and the maximum ship speed 
obtained from FleetMon’s public data, respectively. In Equation 10, Pax is defined as the ME 
power installed on the ship, which can be found in FleetMon’s database as well, while Pacruat 18 
the variable that is estimated. Table 5 summarizes the collected information for all those 
parameters described above for the five case studies. 
Table 5: Data for Pax, Umax and Uacwar that were used as estimation parameters for Pactual 
Ship Number 
Yıax Umax UVaectual 
(KW) (kn) (kn) 
Ship! 11200 | 19 92 
Ship2 , 11655 | 097 TS 
er ER I 7 
Ship4 | 9200 | 525 | BB 
ns ll 560 BA 
330 
331 
332 
333 
334 
335 
336 
337 
338 
339 
340 
341 
342 
343 
344 
Moreover, for all cases examined, we considered that Auxiliary Engines (AE) were not 
operational for different reasons in each case. For ships 1, 2 and 3 (container vessels), very limited 
use of AE is expected in cruise conditions and the LF is assumed to be 0% (Grigoriadis, et al., 
2021b). For other vessel types, there is generally little information regarding operation patterns of 
their AEs. Ship 4 corresponds to a hopper dredger vessel and it is expected to significantly use its 
AE for special purposes and specifically to dredge sand from the seabed but not during cruising. 
Finally, no evidence of AE operation was found in FleetMon’s public data for barge ships, such 
as Ship 5. Hence, we assumed no contribution to exhaust from AE operation in all cases. 
The next step concerns the total exhaust mass flow calculation that originates from the ME 
of each ship. Equation 11 defines the ME total mass flow estimation which equals to the sum of 
the fuel and air mass flow. The fuel and air mass flow terms are estimated by Equation 12. This 
procedure includes expressions that require the estimation of Paetuat» and the specific fuel oil 
consumption (SFOC) (Grigoriadis et al., 2021a). Estimations and assumptions were considered for 
LHV and the actual air-to-fuel ratio (AFR,2a1) (Grigoriadis et al., 20213). 
Meotal = Mfuel + Mair 
. SFOC +P . . 
Mrfuel — En Mair = AFRr/2a1l " Mfuel 
345 The exhaust gas exit velocity is calculated by the application of the mass continuity formula 
346 (Equation 13), where p is the exhaust gas density computed for ideal gases and A is the total surface 
15