• Journal of Ocean Engineering and Technology
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• v.20 no.1 s.68
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• pp.26-31
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• 2006

Experimental research was undertaken to develop a domestic spray nozzle used on equipment for desalination. First, we made a test set-up in order to confirm nozzle efficiency of spray and distribution under different pressure conditions. Then, we found a maximum spray condition after verifying reliability of this facility. An optimum arrangement of the nozzle, based on the test result, was made using CATIA V5 and EXCEL.

• Journal of the Korea Society of Computer and Information
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• v.24 no.7
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• pp.101-108
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• 2019

In this paper, we propose a new scalable and reliable combat system software in battleship which was developed procedurally in the past. Recently, combat system software is required to change frequently due to addition of new equipment and change of function. To solve those problems, this paper propose how to change combat system software into scalable software using class structure change and design pattern. Simulation results show that our scheme provides better performances and reliability than conventional scheme. Therefore proposed scheme can be efficiently used in Naval combat system.

• Journal of Aerospace System Engineering
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• v.10 no.4
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• pp.67-74
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• 2016

The primary aim for using a Korean Condition Based Maintenance (CBM) system is to maintain military operational readiness using Interactive Collection Analysis Systems (ICAS) installed on naval vessels. Other aims are to preemptively provision maintenance and supply functions, to guarantee economical management of logistical assets, and to implement data driven equipment life cycle management. In order to accomplish these aims, it is necessary to establish standard system conditions. However, because manufacturers do not provide the technology necessary for maintenance management, it is required to retain component performance maps for each piece of equipment, and to accumulate data about frequently occurring fault patterns. This study confirms the validity of component performance maps using micro gas turbines and provides accumulated data on machine break downs. This would allow real time equipment performance checks and present performance trends. Then analysis would provide solutions for maintaining the best machine operating conditions with detailed maintenance manuals for operators. This study is a basis for further research to investigate additional ways to develop CBM using data obtained from naval vessels used in actual military operations.

• Journal of Navigation and Port Research
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• v.45 no.1
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• pp.16-25
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• 2021

Hydrodynamic coefficients should be accurately estimated to predict the maneuverability of underwater vehicles. Various captive model tests have been performed as part of estimation methods for these coefficients. Estimating hydrodynamic coefficients related to roll motion is important because underwater vehicles are sensitive to changes of roll moment. In this research, a pure roll motion equipment was newly designed to simply estimate hydrodynamic coefficients with respect to roll motion. Roll motion was implemented through a brief mechanical mechanism. The principle of operation, application process, and system identification of the equipment are described. An analysis method of the pure roll test is also suggested. Repeated tests of the newly equipment were carried out to check its reproducibility.

• International Journal of Naval Architecture and Ocean Engineering
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• v.10 no.3
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• pp.318-328
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• 2018

Disk type underwater gliders are a new type of underwater gliders and they could glide in various directions by adjusting the internal structures, making a turnaround like conventional gliders unnecessary. This characteristic of disk type underwater gliders makes them have great potential application in virtual mooring. Considering dynamic models of conventional underwater gliders could not adequately satisfy the motion characteristic of disk type underwater gliders, a nonlinear dynamic model for the motion simulation of disk type underwater glider is developed in this paper. In the model, the effect of internal masses movement is taken into consideration and a viscous hydrodynamic calculation method satisfying the motion characteristic of disk type underwater gliders is proposed. Through simulating typical motions of a disk type underwater glider, the feasibility of the dynamic model is validated and the disk type underwater glider shows good maneuverability.

• Journal of the Society of Naval Architects of Korea
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• v.47 no.3
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• pp.321-327
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• 2010

During sailing by wind-driven thrust on the sail, a catamaran sailing yacht generates leeway and heeling. For estimating resistance and moment prediction of a real ship by changing of running attitude, a model test of the ship has to be carried out. This study aims at establishing experimental techniques for a catamaran sailing yacht by changed attitude during running direction. Through the model test, drag and side force of the real ship are predicted. Also through experiment, rolling and yawing moments were considered.

• 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.

• International Journal of Naval Architecture and Ocean Engineering
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• v.7 no.1
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• pp.142-156
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• 2015

A new method for ship Inner Shell optimization, which is called Parametric Inner Shell Optimization Method (PISOM), is presented in this paper in order to improve both hull performance and design efficiency of transport ship. The foundation of PISOM is the parametric Inner Shell Plate (ISP) model, which is a fully-associative model driven by dimensions. A method to create parametric ISP model is proposed, including geometric primitives, geometric constraints, geometric constraint solving etc. The standard optimization procedure of ship ISP optimization based on parametric ISP model is put forward, and an efficient optimization approach for typical transport ship is developed based on this procedure. This approach takes the section area of ISP and the other dominant parameters as variables, while all the design requirements such as propeller immersion, fore bottom wave slap, bridge visibility, longitudinal strength etc, are made constraints. The optimization objective is maximum volume of cargo oil tanker/cargo hold, and the genetic algorithm is used to solve this optimization model. This method is applied to the optimization of a product oil tanker and a bulk carrier, and it is proved to be effective, highly efficient, and engineering practical.

• Journal of the Society of Naval Architects of Korea
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• v.54 no.6
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• pp.447-452
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• 2017

A rigid body supported by 4 linear springs has been analyzed, to investigate the effects of eccentricities on the vibration responses for naval shipboard equipments supported by elastic mounts. Considering mount eccentricity (the location of the center of spring reaction forces relative to the mass center) and excitation force eccentricity (the location of the center of the excitation force relative to the mass center), the vibration phenomena have been formulated and discussed. Also, the effects of the eccentricities have been evaluated and discussed for the elastically mounted naval shipboard equipment. Results show that the mount eccentricity has little effects on the structure-borne noise above the natural frequency of the system, however the excitation force eccentricity has significant effects all over the frequency range.

• Journal of Computational Design and Engineering
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• v.1 no.4
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• pp.266-271
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• 2014

The survivability of the naval ship is the capability of a warship to avoid or withstand a hostile environment. The survivability of the naval ship assessed by three categories (susceptibility, vulnerability and recoverability). The magnitude of susceptibility of a warship encountering with threat is dependent upon the attributes of detection equipment and weapon system. In this paper, as a part of a naval ship's survivability analysis, an assessment process model for the ship's susceptibility analysis technique is developed. Naval ship's survivability emphasizing the susceptibility is assessed by the probability of detection, and the probability of hit. Considering the radar cross section (RCS), the assessment procedure for the susceptibility is described. It's emphasizing the simplified calculation model based on the probability density function for probability of hit. Assuming the probability of hit given a both single-hit and multiple-hit, the susceptibility is accessed for a RCS and the hit probability for a rectangular target is applied for a given threat.