• Journal of the Society of Naval Architects of Korea
• /
• v.45 no.6
• /
• pp.601-610
• /
• 2008

This paper deals with a new geometrical surface modeling method of forebody's hull form which is fully defined by form parameters. The complex hull form in the forebody can be modeled by the combination of three parts: bare hull, bulbous bow and blending part which connects a bare hull and a bulbous bow. All these subdomain parts are characterized by each own form parameters and constructed with simple surface model. For this, we need only 2-dimensional hull form data and then the form parameters are calculated automatically from these data. Finally, the smooth hull form surfaces are generated by parametric design and fair-skinning. In the practical point of view, we show that this new method can be useful and efficient modeling tool by applying to the hull form surface modeling of Panamax container's forebody.

• Journal of Ocean Engineering and Technology
• /
• v.14 no.2
• /
• pp.112-116
• /
• 2000

To determine a preliminary hull form with a minimum viscous resistance this study considers the systematic variations of full form and calculations of the viscous resistance for varied hull forms. A preliminary hull form can be determined from a parametric study of viscous resistance.

• Korean Journal of Computational Design and Engineering
• /
• v.13 no.6
• /
• pp.440-449
• /
• 2008

This paper deals with a method calculating various hull form parameters which are required in numerical analysis for ship performance such as motion, maneuverability, resistance and propulsion, etc. After the hull form is designed, before the model tests the ship's performances are evaluated by various analysis tools in which the hull form parameters are used with many kinds of forms aside from offset data. Here, The hull form parameters characterize the properties of hull form and contain positional, differential and integral information implicitly. Generally, the commercial CAD-system has not functions enough for supporting these form parameters and therefore each shipyard uses its own in-house analysis program as well as commercial analysis software. To overcome these limitations, modules for supporting these analysis programs have developed. The modules contain cubic composite spline cure using local curve fairing, intersect algorithm, Gaussian integral, and other geometric techniques needed in calculating hull form parameters. Using our analysis-supporting modules, a complex hull form can be remodeled exactly to the hull form designed by CAD-system and any hull form parameter required in various performance analyses can be calculated.

• Journal of the Society of Naval Architects of Korea
• /
• v.41 no.3
• /
• pp.1-12
• /
• 2004

In order to prepare the fuel-economic hull form design method for fine higher-speed ships, systematic theoretical and experimental study has been performed on the relation between hull form characteristics and ship's resistance and on the effect of the optimization of main hull form characteristics. The results of this study provide not only a great insight into the relation between ship's resistance and hull form characteristics, but also a proper direction of the optimization of main hull form characteristics for the improvement of ship's resistance characteristics.

• Journal of the Society of Naval Architects of Korea
• /
• v.49 no.5
• /
• pp.391-399
• /
• 2012

This paper presents a method of hull form design for the assistant vessel which is used both as a lighting boat and a fish carrying boat for the fleet of newly formated purse seiner vessels. The optimum hull form parameters are searched by the Sequential Quadratic Programing(SQP) method with the power estimation method of Van Oortmerssen. The prismatic curve is redesigned from that of the reference hull by the Lackenby method. Through the modification of the hull form by using a CAD system, the design procedure is completed. The resistance performances of the reference and the modified hull forms are estimated by using a numerical simulation method. Also, the estimation of seakeeping ability and stability for the modified hull forms are carried out. And then, an optimum hull form is proposed for the designed hull form. Ship model tests for the reference and the designed hull forms are carried out at ship model basin. The results of the experiments show that the effective horse power of the designed hull form is about 22% smaller than that of the reference hull form at design speed. The designed hull form proposed in this study will contribute to the development of the hull form for Korean large purse seiner vessels.

• Journal of the Society of Naval Architects of Korea
• /
• v.41 no.3
• /
• pp.60-71
• /
• 2004

Nowadays, We have had a growing interest in high-speed vessels' because it is very important to save time and cost in marine transportation. The development of hull form for high-speed vessels is high priority to secure the competitive power for the transportation of cargos. Therefore, the demand of the high-speed vessels is gradually increased, but the conventional hull forms are limited by rapidly increasing resistance upon the increase of ship speed in high-speed region. Therefore, new concepts for the hull form of high-speed vessels have been requested. One of the derived hull forms for that demand is the hull form of trimaran type. Trimaran has a very slender main hull as compared with conventional single hull so that is reduced in wave resistance. The slender main hull has the undesirable characteristics of stability, but two side hulls make up for the week points in the stability. That is, trimaran is able to have desirable performances for the resistance and stability. In this paper, for the design of 200TEU class container vessel with trimaran type, which will be cruised in Yellow-Sea region, firstly a preliminary hull is designed, and the model test is carried out with the variation of side hull position. From the experience of the preliminary hull form design, an improved hull form for the 200TEU container are designed, and the model tests are carried out. Also, a numerical computation technique is adopted for the simulation of flow phenomena around the designed hull forms. The final hull form is compared with existing ships for the resistance performance from the computation with computer and ship model tests.

• Journal of Ocean Engineering and Technology
• /
• v.13 no.4 s.35
• /
• pp.174-181
• /
• 1999

A form parameter method compounds the form parameters which define the hull geometric characteristics. This method can transform a hull form by changing the form parameters. The form parameter method is a hull define method without utilization of mother ships. However it is difficult to determine these form parameters. Thus, we are complemented the form parameter method using the neural networks. It is found that the form parameter method using the neural networks is efficient in hull form design by consideration of application examples.

• Journal of the Society of Naval Architects of Korea
• /
• v.29 no.2
• /
• pp.8-17
• /
• 1992

There has been considerable reseach on the representation of a hull form which is a 3-dimensional free surface. A form parameter method to describe the hull form by means of form parameters which represent the characteristics of the given hull form geometry has been recently paid special attention with the advent of powerful computer. However, there have been reported many problems to the conventional form parameter for the practical hull form generation. In the present paper, an attempt has been made to creak hull form by combining the form parameter method with the B-spline curve which can be best fitted to free surfaces. In an application, the present method is used to generates a Bulk carrier hull form and compared with the existing hull form to prove its applicability for the hull form generation.

• Journal of the Korean Society of Fisheries and Ocean Technology
• /
• v.44 no.1
• /
• pp.68-74
• /
• 2008

This study is concerned with the development of the basic planing hull form of small fishing boat in 25 knots high speed. A series of model test to determine the optimum performance hull form of actual fishing boat with 10 gross tonnage was carried out for 5 models made available planing hull form in the circulation water channel. Model test was performed with the resistance test to study the hydrodynamic characteristics of model ships and the sinkage and trim measurement to investigate the stability of model ships and also the wave pattern observation to analyze the effectiveness of model ships. As the result, the planing hull form of P-4 with deep V type bow can be derived as the best hull form with good performance especially in ship's resistance efficiency showing less residual resistance and sinkage and trim and the spray effect, etc..

• Journal of Ocean Engineering and Technology
• /
• v.12 no.3 s.29
• /
• pp.103-111
• /
• 1998

This paper describes the initial hull form design process which generate a hull form using a neurofuzzy modeling. Neurofuzzy system is to combine the merits of fuzzy inference system and neural networks. Therefore it has structured knowledge representations as well as adaptive capacities. Initial hull form design stage is the process which generate an adoptable hull form from the limited design information and multi-decidions condidering correlations with design factors. It can be assidted efficiently by neurofuzzy system. This paper suggests two methods of an initial hull form generation using the neurofuzzy modeling and B-spline theory. and examines the usefulness of suggested method through its application examples.