Traditional ship design practices suggest that the optimum hull shape minimizes the beam
of a vessel. However, recent studies on coaster tankers and typical west coast fishing
vessels show that the addition of parabolic bulbs to a vessel's parallel mid body can
significantly reduce the wave making resistance. These parabolic bulbs are added at the
waterline and create their own wave pattern. The waves created by these bulbs can
interact with the shoulder wave system of the base hull in a beneficial manner for certain
speed ranges. Previous parabolization studies have been primarily experimental in nature,
and have focused on vessels with small length to beam ratios, typical of workboats. This
thesis uses both numeric tools and experimental approaches to alter the waterlines of a
slender, high speed trimaran.
A Michell's integral based solver and a Rankine source panel method were used to
predict the wave making characteristics of the trimaran. A parametric study, varying the
size and location of bulbs, was performed first on only the centre hull to identify
beneficial arrangements. The study has then been extended to the trimaran to evaluate
the additional wave interactions from the outriggers.
Calculations done by both numeric methods predicted reductions in wave resistance due
to the increase of the trimaran's beam at the waterline. Experimental work confirmed the
differing wave interactions seen as a result of hull form parabolization, and a new
trimaran form was designed that reduced the total resistance of the vessel by up to 6%. / Applied Science, Faculty of / Mechanical Engineering, Department of / Graduate
| Identifer | oai:union.ndltd.org:UBC/oai:circle.library.ubc.ca:2429/17808 |
| Date | 05 1900 |
| Creators | Vyselaar, Daniel P. |
| Source Sets | University of British Columbia |
| Language | English |
| Detected Language | English |
| Type | Text, Thesis/Dissertation |
| Rights | For non-commercial purposes only, such as research, private study and education. Additional conditions apply, see Terms of Use https://open.library.ubc.ca/terms_of_use. |
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