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respectively. The last two are maximum NO2 concentrations on Deckhouse and E/R intake. As for the
name of checking points, reference can be found in Figure 5-(c). The last item ‘Exhaust Performance’
is the gradation of the exhaust performance obtained by summarizing results of all the items. If any of
the first four items is ‘absolutely unsatisfactory’ (X ), the final result becomes ‘absolutely
unsatisfactory’, and the exhaust performance also becomes ‘absolutely unsatisfactory’ if the maximum
NO2 concentration on E/R intake or Deckhouse is higher than 3 ppm, even if there is no ‘absolutely
unsatisfactory’ in the results of the first four items.
When all the evaluation results of the smoke exhaust performance are investigated, dependence of the
smoke exhaust performance on the deckhouse height and the funnel height reveals clearly. The smoke
exhaust performance does not significantly depend on the deckhouse height while it is highly
dependent on the funnel height, i.e., it improves with the increase of the funnel height. From the
inspection of the relation between the funnel height and the exhaust performance it is concluded that
the smoke exhaust performance will be satisfactory if the ratio of funnel height to deckhouse height is
1.3 or larger. When it comes to the funnel position, as mentioned before, it’s beneficial to the smoke
exhaust performance to locate the funnel as far away from the deckhouse as possible.

Figure 6: An Example of Change of NO2 iso-surface according to the deckhouse height

Figure 7: An Example of Change of NO2 iso-surface according to the funnel height
TABLE 2
EXAMPLES OF EVALUATION OF THE SMOKE EXHAUST PERFORMANCE

NO2 on Surface 1 0 0 0 0
NO2 on Surface 2 0 A A 0
I Max.NOzonDeckhouseside I 0.72 I 0.53 I 2.79 I 2.20 I