Original articles
Systematic study on the hull form design and resistance prediction of displacement-type super-high-Speed ships
KEH-SIK MIN and SEON-HYUNG KANG
Hyundai Maritime Research Institute, Hyundai Heavy Industries co., Ltd., 1 Cheonha-Dong, Dong-Gu, Ulsan 682-792, Korea
Abstract： Systematic theoretical and experimental studies were carried out to establish methods for hull form design, optimum dimension selection, and resistance estimation for displacement-type super-high-speed ships. In this study, a theoretical hull form design method for displacement-type super-high-speed ships was first developed using the minimum resistance theory and a sectionally varying hull form equation. Using an established hull form design method, a series of 60 hull forms were prepared with systematic variations of the most important design variables, and model tests were conducted for these ship models. Finally, regression analyses were performed for the results of the model tests. The study was very successful, and the prepared computer programs are now being actively used as efficient tools for the design of the displacement-type super-high-speed ships.
Key words： hull form design, super-high-speed ships, regression analysis, resistance prediction
Address correspondence to： K.-S. Min
Received for publication on Jan. 23, 1998; accepted on May 15, 1998
Introduction
In 1990, reflecting a world trend and international environmental changes, we prepared a 3-stage R&D program for super-high-speed ships, and actively carried out the R&D work following the plan established. However, the ultimate goal of the research is the development of super-high-speed ships with a deadweight over 10000 tonnes. Therefore, the 1st- and 2nd-stage programs for the development of small-size and medium-size super-high-speed ships are regarded as intermediate steps toward achieving this goal, and decisions on ship type and main characteristics have been
made with this in mind.
In order to increase a ship's speed significantly, it is necessary to prevent a rapid increase in wave resistance. This can be achieved in several ways. One way is to use dynamic or static lift effects, and another is to design the hull form of displacement-type ships to be very narrow.
Hydrofoil boats and traditional planing-hull ships are typical examples of dynamic-effect ships, and the aircushion vehicle and the surface-effect ship resemble
static-effect ships. However, dynamic- and static-effect ships have their own shortcomings. In general, they have very poor seakeeping qualities. Furthermore, it is extremely difficult to increase ship size beyond a certain limit, and this can be regarded as a fatal disadvantage of such ships.
On the other hand, the hull form of displacement-type catamarans could be very narrow in order to achieve the goal of high speed by preventing a rapid increase in wave resistance. In fact, catamarans have many practical advantages such as a large deck area, high stability, superior maneuverability, easy operation and maintenance, etc. However, their most important merit is the fact that ship size can be easily increased without any limitations and without sacrificing any other characteristics. The general advantages of catamarans could be improved still further by properly combining the buoyancy of the hull and the hydrofoil system which produces dynamic lift. Research on the hydrofoil system design has been carried out separately. In this paper, discussions are restricted to the study of the hull form itself.
The hull form design method and the dimension optimization procedure developed in this study could be utilized for both high-speed displacement-type mono-hull ships and catamarans. In the resistance characteristics of catamarans, however, interaction between the two demi-hulls decreases with increased ship speed. In particular, the interaction effect becomes less after the final hump of the residual resistance curve. Therefore, it is quite acceptable to adopt the mono-hull form
