|Longitudinally directed bank effects|
Lataire, E.; Vantorre, M.; Delefortrie, G. (2015). Longitudinally directed bank effects, in: MARSIM 2015, International Conference On Ship Manoeuvrability And Maritime Simulation, 8th – 11th September 2015, Newcastle University, United Kingdom: proceedings. pp. [1-14]
In: (2015). MARSIM 2015, International Conference On Ship Manoeuvrability And Maritime Simulation, 8th – 11th September 2015, Newcastle University, United Kingdom: proceedings. Newcastle University. School of Marine Science and Technology: Newcastle. , more
In confined waterways , the water displaced by a ship is squeezed both under and along the hull. The resulting pressure distribution on the hull causes a combination of forces and moments on the vessel. If the presence of one or more banks generate extra hydrodynamic pressures, this combination of forces and moment is known as bank effects. Based upon the model tests carried out in the fully automated towing tank for manoeuvres in shallow water (cooperation Flanders Hydraulics Research - Ghent University, at Flanders Hydraulics Research in Antwerp, Belgium) , a mathematical model for the increased resistance because of the presence of banks is proposed. The increase in resistance is not only caused by a more confined blockage ratio but also by the relative lateral position of the ship in the cross section. The proposed mathematical model takes into account the shape of the cross section without overestimating the influence of the bathymetry at a larger distance, nor by underestimating the impact of the bathymetry closer to the vessel. This is obtained by defining an equivalent blockage, as well as a tuck number that takes into account the increased return flow along a ship in confined waters.