• Journal of Ocean Engineering and Technology
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• v.22 no.4
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• pp.84-89
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• 2008

It is hard to find experimental data for a model test of small high-speed planning boats. It is difficult to verify the performance seen in a model test for a high-speed boat because the ship-model scale-ratio is very small and the flow velocity of the circulating water channel and the X-carriage speed of the towing tank are restricted. Therefore most hull-form designs for high-speed small boats depend on the sea-trial test result for similar boats or evaluation through numerical calculations. This study investigated the anti-rolling effect of the stern sub-body in a 50-knot doss planning boat. To carry out this work, new model test procedures were set up in the actual sea. Using this method, the anti-rolling effect of the stern sub-body was investigated. A stern sub-body attached to a planning boat was proved to be effective in reducing the roll and pitch angle.

• Journal of Mechanical Science and Technology
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• v.14 no.4
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• pp.448-455
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• 2000

The bow wave breaking and the viscous interaction of stern wave are studied by simulating the free-surface flows. The Navier-Stokes equation is solved by a finite difference method in which the body-fitted coordinate system, the wall function and the triple-grid system are invoked. After validation, the calculations are extended to turbulent flows. The wave elevation at the Reynolds number of $10^4$ is much less than that at $10^6$ although the Froude number is the same. The numerical appearance of the sub-breaking waves is qualitatively supported by experimental observation. They are also applied to study the stern flow of S-103 for which extensive experimental data are available. Although the interaction between separation and the stern wave generation are not yet clear, the effects of the bow wave on the development of the boundary layer flows are concluded to be significant.

• Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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• 2003.10a
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• pp.226-231
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• 2003

The viscous interaction of stern wave is studied by simulating the free-surface flows, including sub-breaking phenomena around a high speed catamaran hull advancing on calm water. The Navier-Stokes equation is solved by a finite difference method where the body-fitted coordinate system, the wall function and the triple-grid system are invoked. The numerical appearance of the sub-breaking waves is qualitatively supported by the experimental observation They are also applied to study precisely on the stern flow of S-103 as to which extensive experimental data are available. For the catamaran, computations are carried out for the mono ana twin hulls.

• Journal of Navigation and Port Research
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• v.31 no.10
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• pp.813-818
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• 2007

There are the C.W.C and Towing Tank to the model-test equipments of the boat. A model testing of the high speed boat have a difficult in the performance verification because of very a small the scale-ratio of the ship-model and restricted by flow-velocity of the C.W.C and X-carriage velocity of the T.T. In general, the stepped hull boat is a high of fuel-efficiency because of the resistance reduction by a small wetted surface-area in correspond without stepped-hull boat. But It have a tendency to be bad the rolling performance by reduced stern wetted-area In this paper, the high speed stepped planning-boats with & without attached a stern body were performed to compare the effect of resistance and rolling performance by using sea model-test method.