Page 490 - Practical Design Ships and Floating Structures

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Level Judging Rule
SI Absolutely Satisfactory, Smoke is hardly disturbed, No possibility of pollution
0 Marginally Satisfactory, Smoke is disturbed a little, No possibility of pollution
Marginally Unsatisfactory, Smoke is disturbed significantly, a little possibility
A
of pollution
x Absolutely Unsatisfactory, Smoke is severely disturbed, Pollution occurs surely

4 CONCLUSIONS
Before the main calculation, influence of the hull and other appendages on the flow around the funnel
was investigated through several calculations. It was concluded that the hull must be modeled, but the
radar mast and on-deck pipe system need not to be modeled due to their minor effects on the flow field
around the funnel.
The smoke exhaust performance is not directly influenced by the deckhouse height but it improves
with the increase of the funnel height. In practical design, the funnel would show a satisfactory smoke
exhaust performance when the ratio of funnel height to deckhouse height is 1.3 or larger. The effect of
the funnel position on the smoke behavior did not appear obviously when the calculation results were
inspected with individual measures because the range of the variation was somewhat small. But when
all the estimation results were taken into consideration, it could be concluded that it’s beneficial to the
smoke exhaust performance to locate the funnel as far away from the deckhouse as possible.
The quantitative accuracy of the results in this study is not guaranteed, so caution is required when this
paper is referred to. The quantitative validity of the analysis of the smoke exhaust performance using
CFD needs to be verified for the direct use of the results, and this verification work can be executed in
the near future.

References
[ 11 (1986). A Method to Predict Stack Performance. Naval Engineering Journal. 35-46
[2] (1 998). Fluent User h Guide, Fluent Inc.
[3] Gary J. Baham and Donald McCallum. (1977). Stack Design Technology for Naval and
Merchant Ships. SNAME Transactions 85,324-349
[4] Jaedon Yoon, Eunseok Jin and Yongsoo Kim. (2000). Design of the Accommodation and
Funnel in a Merchant Ship for Favorable Smoke Emission Performance. The 5th Korean Fluent
Users’ Group Meeting.
[SI (2000). Occupational Exposure Limits 2000. Health andSafety Executive.
[6] (1998 - 2000). Internal R&D Reports, Duewoo Shipbuilding andMarine Engineering Co., Ltd.