The computation referred to the towing tank tests performed by MOERI on the KCS.

The length between perpendiculars is 7.2786 m (scale factor = 31.6) and the body draft is 0.3418 m. The water density considered is 999.1 kg/m³. The position of the center of gravity along the X-axis has been estimated using the tool “domhydro” resulting in a location (X=-11.7, Y=0, Z=-0.115 ) in the global reference frame. The model contains the hull and the rudder of the KCS.

The first case referred to case 2_1 of the 2010 Gothenburg workshop. The vessel is moving with a speed of 2.196 m/s (corresponding to a Froude number of 0.26). In these cases, the trim and the sinkage are blocked. The geometry contains only the hull. The output of the first calculation will be:

• Wave elevation along a longitudinal section
• Wave elevation along the hull
• Wave elevation contours
• Axial velocity and cross-flow near the engine shaft

The second calculation referred to the cases 2_2a of the Gothenburg workshop. it concerns the resistance calculation of the KCS while it is moving with a speed of 2.196 m/s. The trim and the sinkage are still blocked. The only difference with the previous case is the rudder which is present for the second case and not for the first. The output of this calculation will be:

• Drag comparison with experimental data
• Visualization of the free surface
• Wetted area
• Hydrodynamic pressure on the hull                      

The third case referred to case 2_2b of the Gothenburg workshop. It concerns the resistance calculation of the KCS at different speeds from 0.92 m/s to 2.38 m/s (corresponding to a variation of the Froude number from 0.1083 to 0.2816). In this case, the trim and the sinkage are solved. In terms of output, the following will be presented:

• Drag, Trim, and Sinkage comparison with experimental data
• Visualization of the free surface
• Wetted area
• Hydrodynamic pressure on the hull

As the conditions of all cases are symmetric only half of the geometry is simulated.

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Posted by Benoit Mallol

Benoit holds a master's degree in Mechanical and Numerical modeling from the University of Bordeaux (France) with a specialization in CFD dedicated to free surface flows. For more than 10 years, he has been working on unstructured meshing strategies and marine applications. As head of the marine group and head of the unstructured meshing group, Benoit drives the product roadmaps, acts as the CFD technical expert to support all our offices around the world, and makes sure that the software remains the reference on the different markets.