Example Patch Boundaries

The first example shows patching of an aft end. The boundaries that are used for the patches are shown in the diagram below. Plines have been constructed from the stern profile to the FOS. These plines follow inflection points in the surface. They intersect the FOS at the same position as specific stations, allowing patches to use the FOS as a common boundary. The plines were generated by intersecting a cline in buttock view with all orthogonal curves.

Figure 3:163. The FOS, Stations, Waterlines and Plines to be used for Patching.

The following figure shows the same aft end with patches fitted to the previously defined boundaries. It can be seen that all patches have common boundaries and corner positions.

Figure 3:164. The Fitted Patch Boundaries.

The second example shows a fore end with bulb. Plines have been constructed which follow zones of similar curvature from the stem profile aft. These plines continue to the bilge and finally to the stern profile. A vertical pline is needed to create a patch boundary aft of the knuckle. A vertical pline has also been constructed on the bulb. A single large patch would not be able to accurately model the full bulb, so splitting the bulb into two smaller patches enables closer fitting of the patches to the surface mesh.

It can be seen how smaller patches have been used in the stem region and larger patches used towards midships.

Figure 3:165. The FOS, Stations, Knuckles and Plines to be used for Patching.

The diagram below displays the patch boundaries after fitting.

Figure 3:166. The Fitted Patch Boundaries.