Projects

Experimental Study on the Motions and Loads on Catamarans (CATAMARANS)

Duration: 01.01.1997-31.12.1999 (36 months)

Coordination: Canal del Pardo

Partners: Instituto Superior Técnico

Funding Entity: EU - Programme Large Scales Facilities

The catamaran is a very suitable ship for special services, such as fast passenger ferry, oceanographic vessel, supply or rescue ship or even special naval ships. In particular catamarans are the most accepted type of high speed vessel for passenger transportation. Some of the advantages are the large deck area, large transverse stability, low wave resistance at high speed. However, to carry out this mission efficiently the ship must behave with small motions and accelerations, or in other words, the deck area must behave with small motions and accelerations, or in other words, the deck area must behave as a stable platform when the ship travels in a seaway. There are several complex phenomena, which make the study of the seakeeping behaviour of catamarans a quite difficult task, namely the interference effects between the two hulls, the influence of the relatively high speed, and the viscous effects. In fact here are not enough experimental data available in the literature, so one of the objectives of the project is to obtain the necessary experimental data to validate our existing ship motion numerical model and develop and implement the next research step which is the determination of wave induced loads in catamarans. Experiments will be carried out to determine the heave and pitch added mass and damping coefficient for head seas at four different speeds. Experiments will also be carried out to assess the viscous-lift coefficient and the cross-flow drag coefficient of the hydrodynamics forces due to viscous effects. As for the induced motions, fats were proposed in regular waves for tree Froude member and 5 wave heading between head and following waves. Measurements will be obtained of the absolute and relative motions, accelerations, structural loads and impact loads. The structural loads to be measured are the lateral and vertical shear forces and the vertical bending moment at the cross deck at 3 positions along the length of the hull. The impact pressures will be measured bellow the cross decks.

Project Team

Associated Publications