Ship drag in confined sections: Effect of depth, asymmetry and flow criticality
In: Ocean Engineering. Pergamon: Elmsford. ISSN 0029-8018; e-ISSN 1873-5258, more
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| Keywords |
Harbours and waterways > Manoeuvring behaviour > Bank effects
Harbours and waterways > Manoeuvring behaviour > Influence under keel clearance
Harbours and waterways > Resistance and propulsion > Bank effects
Harbours and waterways > Resistance and propulsion > Influence under keel clearance
Physical modelling
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| Authors | | Top |
- Delefortrie, G., more
- Candries, M., more
- Van Zwijnsvoorde, T., more
- Lataire, E., more
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| Abstract |
The present paper proposes a qualitative prediction of the drag increase felt by a displacement ship when sailing in a confined cross section. Resistance computations for ships are usually limited to deep open water and focus on the classical breakdown of the resistance into friction, form and wave making resistance. Previous attempts, in open literature, to include confinement effects mostly focussed on adapting one or more of these resistance components to shallow water, where the effect of lateral restrictions is usually omitted. Inspiration was taken from the Raven method for the shallow water correction of the resistance, recommended by the ITTC. The present article extends this method towards shallower water depths and lower under keel clearances, including the effects of sailing closer to a bank or in (near) transcritical flow conditions. The method is applied satisfactorily to measurements carried out in the Towing Tank for Manoeuvres in Confined Water, covering a range of complex cross sections and multiple ship types. |
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