• Journal of the Society of Naval Architects of Korea
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• v.42 no.1 s.139
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• pp.34-42
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• 2005

An overview of 30 feet sailing yacht design is presented, with an emphasis on the factors contributing to start-up popularization. After prescribing the configurations of the purposed yacht, the design of the hull form with a rudder and a keel, are schematically described. Also the determinations of the dimensions of the sail and rig are performed. Finally this paper is associated with the state-of-the-art of calculating sailing yacht performance as this is performed in velocity prediction program (VPP). The VPP results shows a typical shape of a sailing yacht and the designed yacht has the best performance at 120 degree angle of true wind with 20 knots.

• Journal of the Society of Naval Architects of Korea
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• v.42 no.1 s.139
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• pp.24-33
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• 2005

It is important to understand the flow characteristics around two sails of a sloop yacht. In this paper a computational aerodynamic investigation is performed over sail-like airfoils similar to the main and iIb sails of a 30 feet sailing yacht. Lift and drag are calculated for various conditions of slit distance between the two sails and overlapped length of the jib sail. The thrust and CE(center of effort) of the sail system are obtained. It is found that the combination of two sails produces the thrust force larger than the sum of the thrust force of each sail standing separately and the slit distance of the two sails are important factor to increase lift force.

• Journal of the Society of Naval Architects of Korea
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• v.43 no.4 s.148
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• pp.431-439
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• 2006

Due to the limitation of size of the test section, blockage effects could not be avoided in the model test of yacht sails for common wind tunnels. In this paper, a numerical analysis is performed to investigate the blockage effects on the lift and drag forces measured from wind tunnel experiments for a 30 feet sloop yacht sail. Complex airflows around the jib and main sails including three-dimensional flow separations are calculated for various close-hauled conditions. It is found that the blockage of a wind tunnel changes the flow separation and consequently the lift and drag forces of the sails, especially the main sail, reduce and increase, respectively, due to the blockage effects.

• Journal of the Society of Naval Architects of Korea
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• v.48 no.5
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• pp.445-450
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• 2011

In order to estimate a yacht sail performance, measuring system of aerodynamic forces acting on the yacht sail is constructed and experiments of flexible model sail are carried out at the medium-size subsonic wind tunnel of Chungnam National University. Experimental results for a flexible sail are compared with experimental and numerical results of fixed shape sail. In case of a fixed shape sail, lift and drag coefficients are rarely changed at all velocity conditions. However, those of the flexible sail are decreased as the incoming velocity is increased. These are understandably resulted from shape variations due to the flexible material. Therefore aero-elastic similarity should be more carefully considered in the model test rather than other similarities.

• Journal of the Society of Naval Architects of Korea
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• v.47 no.4
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• pp.477-486
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• 2010

During sailing by wind-driven thrust on the sail, a catamaran sailing yacht generates leeway and heeling. For predicting sail force, a model test was carried out according to running attitude. Through the model test, drag and side force of the real ship was predicted. A purpose of this study is to find sail force to C.E from changed attitude during running direction. By balance of hull and sail, a heeling force of designed sail is predicted. Also through heeling force and driving force, total sail force and direction from C.E are considered with changed mast including leeway and heeling.

• Journal of the Society of Naval Architects of Korea
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• v.48 no.4
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• pp.308-316
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• 2011

Although a yacht sails operate with large displacement due to very thin thickness, many studies for flow around yacht sails have not considered the sail deformation. The sail deformation not only caused a change in the center of effect(CE) on the sail but also a change in the thrust of the sail. The change of the CE and thrust affects the center of lateral resistance(CLR) and side forces of the hull, and the balance of the yacht. These changes affect the motion of the yacht which changes the velocity of the yacht. Thus, when analyzing the flow around yacht sails, the sail deformation should be considered. In the present study, fluid-structure-interaction(FSI) analysis of a two dimensional section of yacht sails was performed to consider the effects of sail deformation on the lift and drag performance. FSI and moving mesh methods were studied. Computational methods were verified using benchmark test cases such as the flow around horizontal and vertical cantilever beams. Shape deformation, pressure distribution, lift forces and separation flow were compared for both rigid and deformable sail.

• Journal of the Society of Naval Architects of Korea
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• v.44 no.3 s.153
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• pp.248-257
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• 2007

Turbulent flows around a sailing yacht hull were calculated using CFD technique. Grid system was generated by using Gridgen package and Fluent package was used to calculate flows around a 30ft-class yacht hull designed by MOERI. The drafts at starboard and port sides of a yacht. when the hull was heeled, were determined by adjusting the same displacement in the generated grid system. Pressure distribution on the sailing yacht hull was obtained and the changes of drag and side force by heel and leeway variation were shown. The flow calculations have been carried out both with and without free surface, and keel and rudder were included for both cases. It was found that the calculated results with free surface gives better agreement with experiments than those without free surface, although there are still a room for the improvement in correct prediction of forces.

• Journal of the Society of Naval Architects of Korea
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• v.44 no.4
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• pp.451-458
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• 2007

A preliminary design approach for superyachts is introduced. The state-of-the-arts of superyachts is investigated and their characteristics are indirectly examined by analyzing the data collected from built vessels. The analysis of data provides a guideline for the establishment of an preliminary hull form of a superyacht. The rules and regulations governing the design and construction of superyachts are collected and considered. A modeling approach for prompt and efficient design is also introduced. A sample hull form of a selected superyacht is constructed using commercial design packages not only to produce a hull form but to analyze the hydrostatic and hydrodynamic performances of the constructed vessel. Various visualization techniques are considered as an efficient tool for design verification.

• Journal of Ocean Engineering and Technology
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• v.18 no.4 s.59
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• pp.71-76
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• 2004

A Study of the traditional Korean fishing boat is based on a report on an investigation of the Korean fishing boats, conducted in 1921. The report was completed in 1927 with the conclusion of the Southern Sea region and West Sea region studies, which included the investigation oj the entire region. It was a very thorough and scientific investigation of Korean fishing boats, which has been published in three volumes. Based on this report, this paper surveys the characteristics and the hull form of the traditional Korean fishing boats. As a result, we find ${\cdot}out$ that the hull form of the traditional Korean fishing boat is very similar to that of modern sailing boat. Thus, it is a good candidate for the development of the modern sailing boats for the Korean Sea.

• Korean Institute of Interior Design Journal
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• v.16 no.6
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• pp.224-231
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• 2007

Superyachts are passenger vessels whose hull exceeds 24m. They are a kind of luxurious leisure ships. Interior designers can contribute in the field of space design of superyachts. This study is intended to investigate the space elements and their organization of superyachts for putting the base of superyachts interior design. Especially it is focused on the interior space division by structural elements such as the watertight bulkheads and decks. In this study we analyze general arrangements, floor plans of decks, of 31 superyachts and extract space elements and their disposition in three dimension. On the basis of the space arrangement we classify the types of space organization of superyachts. And then we inquire the interior space division of superyachts, which is characterized by the structural elements of the ship. The watertight compartments made by the bulkheads and decks have a great effect on interior space design in super yachts. The results of this study are summed up as follows: At first, the small-size superyacht has 3 decks and the midium or large-size superyachts has 4decks. Secondly, depending on the number of decks the superyachts has several typical patterns of space organization. Thirdly, in general there are 5-6 watertight compartments on a deck depending on the superyachts scale. Finally, there are distinct separation between the passenger's movement and the crew's movement on the ship.