Ki-Su Kim, "Assessment Method of the Fitness of Initial Arrangement Design of a Naval Ship", Ph.D. Thesis, Seoul National University, 2019.08.29
김기수, "침수를 고려한 함정의 초기 배치 설계의 적합성 평가 방법", 박사학위, 서울대학교, 2019년 8월 29일
Ph.D. Thesis
2020.03.05 12:59
Ki-Su Kim, "Assessment Method of the Fitness of Initial Arrangement Design of a Naval Ship", Ph.D. Thesis, Seoul National University, 2019.08.29
조회 수 138
| 첨부 '1' |
|---|
| Abstract | The initial design of the ship follows several stages to meet the design requirements. Generally, it is based on the design requirements and the information of the buses, and it goes through the steps of selecting the main specifications, selecting the line, selecting the main engine, arranging the layout, calculating the ship, and analyzing the performance. The layout design in the above process depends on the information of the mother ship and the experience of the designer. Accordingly, arrangement design was performed according to qualitative evaluation rather than traditionally quantitative evaluation. Because a person manually manages the layout design and evaluates multiple plans, it takes a lot of time to design the layout. Therefore, in this study, we aimed to automate and optimize quantitative evaluation and review of several for the initial arrangement design of a naval ship. In addition, after the arrangement design, ship calculation process can be done to ensure that the ship has adequate stability during operation. Ship stability is evaluated as intact stability and damage stability. Damage stability is traditionally evaluated considering only the final stage after damage, and there is a lack of evaluation of damage and progress of flooding. In addition, the stability calculation for various things must be carried out through the ship calculation program, which is a process in which many designers take a lot of work like the layout design. In order to overcome the limitations of the existing ship calculation, this study proposes a method to evaluate the stability of the ship by applying intermediate flood analysis as well as intact and damage stability evaluation and applying it to the arrangement design evaluation process. In this study, we considered three aspects of stability, vulnerability, and operability for initial arrangement design of naval ships. To evaluate the stability, the intact stability of the water was investigated. In addition, the damage stability evaluation was carried out considering the recovery of the damage in the general final condition and the intermediate flooding. Intermediate flooding uses PBD (Position Based Dynamics) to calculate the flow rate through the openings in the damaged part and trap, thereby updating the weight and center of gravity of the modified trap. Then, the changed information is substituted into the 6-DOF motion equation to track the behavior of the ship every time step. Through this, it is possible to evaluate the progress of the ship 's flooding through the damage and the damage stability in the process. In order to improve the static stability and damage stability, GZ curve calculation is accompanied. In this study, trim is considered in addition to GZ value calculation considering existing heave motion. The vulnerability assessment of the naval ship considers both the vulnerability of the bulkhead and the vulnerability of the rooms. Vulnerability of the bulkhead was considered as the sum of the bursting pressure on the bulkhead with various damage, and the vulnerability of the compartment was taken into account by multiplying the severity of the compartment with the probability that various damage would affect the compartment. In addition, for the two vulnerabilities, we considered the length, width, and height direction damage probability of the five types of damage (ASMs (Anti-Ship Missiles), torpedoes, mines, collisions, and grounding) In order to quantitatively evaluate the operability of the naval ship, the movement of the crew and cargos between the compartments of the naval ship was considered. For this, the relation between the shortest distance between each rooms and the compartment was considered. The relationship between the compartments was considered through proximity considering both intimacy assessing the affinity of rooms to be close and antagonism between rooms to be far apart. The three evaluations described above have been formulated as a problem for the initial layout design of a ship. The optimization problem design variables were set to the location of the bulkhead and deck, the location of the compartment and the location of the corridor, and the objective function was set to minimize the vulnerability of the naval ship and maximize operability. In order to improve stability, we considered maximizing initial GM as an objective function. In this process, constraints on the positions of the bulkheads and decks, the lengths required by the engine, and the constraints on the extent that each compartment has to be minimized are considered, and the location of the compartment is considered as a constraint in the optimization problem. The optimal design of the initial arrangement design of the naval ship was obtained through this, and it was evaluated whether the optimized arrangement design satisfies the damage stability including the intermediate flooding stage. The initial arrangement design and the ship calculation process described above were developed as one program, and the applicability of this study was confirmed by applying it to the U.S. Navy Destroyer. |
|---|---|
| Publication Date | 2019-08-29 |
