• Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
• /
• 2001.05a
• /
• pp.53-59
• /
• 2001

In this Paper, the resistance performances of twin hull forms, which are simplified as two-dimensional wedge shape, are experimentally investigated in low and middle speed ranges to find out the effect of distance between two hulls and fore-body shape for the future hull form development of catamaran type sweeping vessel. The model tests are performed for seven different cases for three models in the circulating water channel(CWC) of Inha Technical College. The free surface flows are observed together to investigate the relation between resistance performance and free surface characteristics. A conceptual design for the modification of bow hull form is presented and the efficiency is discussed.

• Journal of the Korea Institute of Military Science and Technology
• /
• v.6 no.2
• /
• pp.20-34
• /
• 2003

The good sea-keeping capability of the SWATH(Small Waterplane Area Twin Hull) ship has been attractive for research or surveillance vessels. Especially, for the naval ships accomplishing the underwater acoustic missions, it is necessary to access and minimize the underwater radiated noise level generated by the ships. Therefore, acoustic signature management and control are very important topics for these vessels. Underwater radiation pattern in the low frequency range is dominated by the tonals from the vibration of onboard machinery. In this work, the radiated noise level generated by the propulsion machine in the submerged hull is predicted using the transfer function technique and the hull transfer function for the submerged hull is determined by analyzing the longitudinal/circumferential stiffened infinitely long cylindrical shell and considering the empirical database of the previous vessels. It is confirmed that the transfer function technique can give useful information for identifying the noise source and estimating its contribution to the total radiatied noise level.

• Journal of the Society of Naval Architects of Korea
• /
• v.44 no.4
• /
• pp.370-378
• /
• 2007

In this study. a numerical analysis has been performed for the turbulent flow around a 15,000TEU twin-skeg container ship using a commercial CFD code. FLUENT. The computed results have been compared with the model test data from MOERI. We investigated viscous resistance coefficient. wake distribution and characteristics of the shear flow according to the grid numbers. Although the free surface is approximated by the plane of symmetry in this work. the calculated axial velocity and transverse vector show a good agreement with the MOERI experimental data except for the region of 0.9 level of axial velocity at the propeller plane. The numerical analysis show that commercial CFD code is useful tool for the evaluation of complex hull form with twin-skegs.

• Journal of Ocean Engineering and Technology
• /
• v.18 no.5
• /
• pp.57-63
• /
• 2004

Various propulsion systems, applicable for a G/T 47,000 class mid-size cruise ship, are discussed and a comparative study on stern forms and hull resistance characteristics is carried out, in relation to these propulsion systems. Based on shipyard production logs on similar cruise ships, a reference hull form of a single shaft propulsion system with center-skeg, is generated. Then two new stern hull forms are derived by using a hull transform technique: consisting of one stern form using a twin-skeg system and the other using the Azipod system. Using a CFD-based commercial flaw analysis program, WAVIS (WAve and VIScous flaw analysis system for hull form development), various hydrodynamic characteristics, including wave profiles and ship hull resistance, are compared for three hull forms.

• Bulletin of the Society of Naval Architects of Korea
• /
• v.24 no.4
• /
• pp.53-70
• /
• 1987

The world's largest twin skeg VLBC developed at Samsung shipyard for BHP, Austrailian owner, has been proven as a successful vessel through 1 year's operation record in view of the superior propulsion performances, maneouverability in extremely shallow water and all ship's systems, especially, ship's vibration. The principal technical matter during the design development from the initial design stage to the sea trial has been summarized on this report.

• Journal of the Korean Society of Marine Environment & Safety
• /
• v.23 no.5
• /
• pp.532-540
• /
• 2017

This paper suggests study of basic structure design and structural analysis for the twin car-ferries. The rules and methodology for the strength analysis of medium and small sized high speed vessels with a length of more than 50m and a length/width ratio of more than 12, such as car-ferries, have not been clarified yet. Therefore, in this paper, the members scantling were carried out using the KR Rule, and the car-ferry exclusive vessel standard were further applied to verify the structural strength the design. The scantling of the members is based on the Korea Classification standards, and the car-ferries standards were additionally applied to verify the structural strength of the design. Especially, the ultimate strength of hull girder was additionally carried out by using car-ferry exclusive vessel standard, and proposed to overcome ambiguity of design by existing standard. The results of this study are expected to be useful as basic data related to structural design and structural analysis of high speed twin-hull car-ferries. The present car-ferry design has a sufficient safety margin in strength point of view according to the KR rule.

• 한국기계연구소 소보
• /
• s.17
• /
• pp.145-156
• /
• 1987

A PSWATH is a computer program for the determination of principal particulars of Small Waterplane Area Twin Hull (SWATH) Ship design at the preliminary design stage. This paper describes the PSWATH system and the underlying theory. The major calculation modules are hull definition, resistance and propulsion, weight estimation and pitch stability analysis. Use of the model is illustrated by input, output and means of examples.

• Proceedings of KOSOMES biannual meeting
• /
• 2017.11a
• /
• pp.187-187
• /
• 2017

• Journal of Navigation and Port Research
• /
• v.32 no.8
• /
• pp.583-588
• /
• 2008

The planing craft is designed specifically to achieve comparatively high speed on the surface of the water. In general, the stepped hull craft has effect improvement in speed and fuel-efficiency because of the reduction of total resistance by a small wetted surface area without corresponding stepped hull craft. In this paper, the high speed stepped hull crafts with respect to the number of bottom steps were performed to compare the effect of resistance performance using at-sea model-test method. In conclusion, the stepped hull craft with twin-step was proved to be effective to reduce the total resistance.

• Journal of the Korean Society of Marine Environment & Safety
• /
• v.26 no.4
• /
• pp.403-411
• /
• 2020

This paper discusses the main findings of the development of the twin-hull Car ferry for island freight and passenger transport. The final model had a 19 m wide beam to create enough space for cars on the deck area and thus, enhance the economic feasibility in the market. The vessel had a V-shape with a bulbous bow to minimize the wave-making resistance and the hydrodynamic performance of the ship was verified through computational fluid dynamics. Multi-objective optimization problems of Pareto simulated annealing were used to achieve a weight reduction of approximately 3.9 % and reduce the manufacturing cost. The main results obtained in this study are expected to be useful to engineers and professionals in related industries interested in research on twin catamaran.