• Journal of Ocean Engineering and Technology
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• v.29 no.3
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• pp.217-223
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• 2015

In order to predict the motions of a planing hull in waves, it is necessary to accurately estimate the force components acting on the hull such as the hydrodynamic force, buoyancy, and friction, as well as the wave exciting force. In particular, based on strip theory, hydrodynamic forces can be estimated by the summation of the forces acting on each cross-section of the hull. A non-linear strip method for planing hulls was mathematically developed by Zarnick, and his formula has been used to predict the vertical motions of prismatic planing hulls in regular waves. In this study, several improvements were added to Zarnick's formula to predict the vertical motions of warped planing hulls. Based on calm water model test results, the buoyancy force and moment correction coefficients were modified. Further improvements were made in the pile-up correction. Pile-up correction factors were changed according to variations of the deadrise angles using the results found in previous research. Using the same hull form, captive model tests were carried out in other recent research, and the results were compared with the present calculation results. The comparison showed reasonably good agreements between the model tests and present calculations.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2017.11a
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• pp.236-237
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• 2017

In this research, experimental seakeeping results of Warped hull form 2 on the regular waves were compared with numerical results of strip method and CFD. In case of ship's speed, there are 3 cases (3.4m/s, 4.6m/s, 5.75m/s) for numerical simulation, and they are belong to semi-planing and planing condition. Consequently, in case of strip method, it is shown that the resonance phenomena occurred from around ${\lambda}/L_{OA}=2$ to 4 and RAO value were significantly higher than that of other. this is different from experimental results. In case of CFD, overall trends were similar with experimental values except there are somewhat excessive RAO values around ${\lambda}/L_{OA}=0.5$ to 2.5. these phenomena is confirmed that it became larger as the ship's speed increased, and it was considered that the error occurred because the number of mesh in vertical direction of wave height at ${\lambda}/L_{OA}=0.5$ to 2.5 were relatively less than those of wave height at ${\lambda}/L_{OA}=2.5$ to 5.2.