Go to the main menu
Skip to content
Go to bottom
REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
> Journal Vol & Issue
Journal of Ocean Engineering and Technology
Journal Basic Information
Journal DOI :
Korean Society of Ocean Engineers
Editor in Chief :
Volume & Issues
Volume 27, Issue 6 - Dec 2013
Volume 27, Issue 5 - Oct 2013
Volume 27, Issue 4 - Aug 2013
Volume 27, Issue 3 - Jun 2013
Volume 27, Issue 2 - Apr 2013
Volume 27, Issue 1 - Feb 2013
Selecting the target year
On the Volumetric Balanced Variation of Ship Forms
Kim, Hyun-Cheol ;
Journal of Ocean Engineering and Technology, volume 27, issue 2, 2013, Pages 1~7
DOI : 10.5574/KSOE.2013.27.2.001
This paper aims at contributing to the field of ship design by introducing new systematic variation methods for ship hull forms. Hull form design is generally carried out in two stages. The first is the global variation considering the sectional area curve. Because the geometric properties of a sectional area curve have a decisive effect on the global hydrodynamic properties of ships, the design of a sectional area curve that satisfies various global design conditions, e.g., the displacement, longitudinal center of buoyancy, etc., is important in the initial hull form design stage. The second stage involves the local design of section forms. Section forms affect the local hydrodynamic properties, e.g., the local pressure in the fore- and aftbody. This paper deals with a new method for the systematic variation of sectional area curves. The longitudinal volume distribution of a ship depends on the sectional area curve, which can geometrically be controlled using parametric variation and a variation that uses the modification function. Based on these methods, we suggest a more generalized method in connection with the derivation of the lines for a new design compared to those for similar ships. This is the so-called the volumetric balanced variation (VOB) method for ship forms using a B-spline modification function and an optimization technique. In this paper the global geometric properties of hull forms are totally controlled by the form parameters. We describe the new method and some application examples in detail.
Mechanical Properties of Si
Ceramic Composites with Aligned Whisker Seeds
Kim, Han-Gil ; Bang, Kook-Soo ; Jung, Sang-Jin ; Park, Chan ;
Journal of Ocean Engineering and Technology, volume 27, issue 2, 2013, Pages 8~12
DOI : 10.5574/KSOE.2013.27.2.008
Four kinds of silicon nitride composites with tri-laminate structure were prepared by stacking tapes with aligned
whisker seeds. The composites were fabricated using a modified tape casting method for enhanced alignment of the whisker seeds. The relative densities of all four samples reached 99% at room temperature. The three-point flexural strengths of the samples according to the stacking sequences were measured at both room temperature and 1723 K. The high temperature strength of sample WWW was
MPa. The fracture of sample WWW occurred mainly along the grain boundary. The room temperature strengths of samples OOO, OWO, WOW, and WWW were
Study on Structural Behavior of Pipe Loops Using CAESAR-II
Park, Chi-Mo ; Yoon, Seong-Ryong ;
Journal of Ocean Engineering and Technology, volume 27, issue 2, 2013, Pages 13~18
DOI : 10.5574/KSOE.2013.27.2.013
Most ships and offshore structures are equipped with a variety of pipes, which inevitably contain curved portions. The structural design of these pipes mostly relies on the commercial code, CAESAR-II, which was especially developed for the structural analysis of pipes. This study conducted stress analyses of the same pipe unit, including loops, using both CAESAR-II and MSC/NASTRAN, and compared the results to investigate the characteristics of CAESAR-II. A parametric study was then conducted of the various design variables of pipe loops using CAESAR-II to draw some useful information about the structural characteristics of the loops.
Formulation of Failure Strain according to Average Stress Triaxiality of Low Temperature High Strength Steel (EH36)
Choung, Joonmo ; Nam, Woongshik ;
Journal of Ocean Engineering and Technology, volume 27, issue 2, 2013, Pages 19~26
DOI : 10.5574/KSOE.2013.27.2.019
Stress triaxiality is recognized as one of the most important factors for predicting the failure strain of ductile metals. This study dealt with the effect of the average stress triaxiality on the failure strain of a typical low-temperature high-strength marine structural steel, EH36. Tensile tests were carried out on flat specimens with different notches, from relatively smooth to very sharp levels. Numerical simulations of each specimen were performed by using ABAQUS. The failure initiation points in numerical simulations were identified from a comparison of the engineering stress vs. strain curves obtained from experiments with simulated ones. The failure strain curves for various dimensionless critical energy levels were established in the average stress triaxiality domain and compared with the identified failure strain points. It was observed that most of the failure initiation points were approximated with a 100% dimensionless critical energy curve. It was concluded that the failure strains were well expressed as a function of the average stress triaxiality.
Optimization of Stress and Deformation of Culvert Gate by using RSM and NSGA-II
Kim, Dong Soo ; Lee, Jongsoo ; Choi, Ha-Young ;
Journal of Ocean Engineering and Technology, volume 27, issue 2, 2013, Pages 27~32
DOI : 10.5574/KSOE.2013.27.2.027
A valve is a marine structure that is subjected to multiple seawater loads. Therefore, it is necessary to define the kind of loads applied to it to confirm whether the structure has sufficient strength. In this research, we aimed to find the optimal solution for the stress and deformation of valves under various loads. We first selected design variables and implement a finite element analysis according to changes in the thickness of each component of a valve based on a central composite design. Next we developed a regression model of the response surface. Using this model, we calculated the optimal objective value based on NSGA-II. Finally, to confirm the correspondence between the optimal objective value and the real FEM value, we compared the optimal result and structural analysis result to verify the performance of NSGA-II.
Corrosion Resistance Characteristics of Cold Rolled Steel by Cr-free Green Organic/Inorganic Hybrid Coating Solution
Nam, Ki Woo ; Kim, Jung Ryang ; Choi, Chang Min ;
Journal of Ocean Engineering and Technology, volume 27, issue 2, 2013, Pages 33~38
DOI : 10.5574/KSOE.2013.27.2.033
In the past, a very popular method for reducing the corrosion on zinc involved the use of chemical conversion layer coatings based on
. However, there is an important problem with using chromium salts as a result of restrictive environmental protection legislation. This study investigated the optimum condition for galvanized steel using an organic/inorganic solution with a Ti composition. In the case of a fixed heat treatment time, the corrosion resistance values of LR-0727(1) and LR-0727(2) were improved as the heat treatment temperature increased, and the optimum minimum temperature decreased with the heat treatment time. At the optimum heat treatment condition of two coating solutions, the heat treatment time of the LR-0727(1) solution was shorter than LR-0727(2) for the same heat treatment temperature. LR-0727(1) coated specimens did not show desquamation, and all of the specimens showed a good adhesive property. In contrast, in the case of the LR-0727(2) coated specimens, desquamation arose. Therefore, the adhesive property of LR-0727(1) was superior to that of LR-0727(2). The pencil hardness had a 3H average for all of the coating solutions and heat treatment conditions. In the case of a corrosion resistance test with boiling water, the coated specimens of LR-0727(1) were discolored, but LR-0727(2) was not. Finally, LR-0727(1) was more moisture proof than LR-0727(2).
Applications of Three-Dimensional Multiphase Flow Simulations for Prediction of Wave Impact Pressure
Jeong, Se-Min ; Hwang, Sung-Chul ; Park, Jong-Chun ;
Journal of Ocean Engineering and Technology, volume 27, issue 2, 2013, Pages 39~46
DOI : 10.5574/KSOE.2013.27.2.039
In this study, the impact loads on tank walls by sloshing phenomena and on a tall structure in a three-dimensional rectangular tank were predicted using multiphase flow simulations. The solver was based on the CIP/CCUP (Constraint interpolation CIP/CIP combined unified procedure) method, and the THINC-WLIC (Tangent hyperbola for interface capturing-weighted line interface calculation) scheme was used to capture the air-water interface. For the convection terms of the Navier-Stokes equations, the USCIP (Unsplit semi-lagrangian CIP) method was adopted. The results of simulations were compared with those of experiments. Overall, the comparisons were reasonably good.
Analysis of Risk Control Options for Blockage Treatment
Yoo, Won-Woo ; Park, Min-Sun ; Yang, Young-Soon ;
Journal of Ocean Engineering and Technology, volume 27, issue 2, 2013, Pages 47~52
DOI : 10.5574/KSOE.2013.27.2.047
A subsea chemical injection system treats blockage problems in a subsea production system. It is important to treat problems quickly, because production delays cause fatal profit losses in a subsea production system. Therefore, the subsea industry requires a relatively higher reliability level for a production system compared to other industries. In this study, a subsea chemical injection system (linked to a control system) to inject chemicals into a subsea X-mas tree was analyzed. By using FSA (Formal Safety Assessment), the risk factors were defined and a quantitative risk analysis utilizing FTA (Fault Tree Analysis) and ETA (Event Tree Analysis) was performed. As a result, the effectiveness of a risk reduction option was evaluated.
Development of Particle Simulation Method for Analysis of Fluid-Structure Interaction Problems
Hwang, Sung-Chul ; Park, Jong-Chun ; Song, Chang-Yong ; Kim, Young-Hun ;
Journal of Ocean Engineering and Technology, volume 27, issue 2, 2013, Pages 53~58
DOI : 10.5574/KSOE.2013.27.2.053
Recently, some fluid-structure interaction (FSI) problems involving the fluid impact loads interacting with structures, such as sloshing, slamming, green-water, etc., have been considered, especially in the ocean engineering field. The governing equations for both an elastic solid model and flow model were originally derived from similar continuum mechanics principles. In this study, an elastic model based on a particle method, the MPS method, was developed for simulating the FSI problems. The developed model was first applied to a simple cantilever deflection problem for verification. Then, the model was coupled with the fluid flow model, the PNU (Pusan National University modified)-MPS method, and applied to the numerical investigation of the coupling effects between a cantilever and a mass of water, which has variable density, free-falling to the end of the cantilever.
CFD Simulation of Methane Combustion for Estimation of Fire and Explosion in Offshore Plant
Seok, Jun ; Jeong, Se-Min ; Park, Jong-Chun ; Paik, Jeom-Kee ;
Journal of Ocean Engineering and Technology, volume 27, issue 2, 2013, Pages 59~68
DOI : 10.5574/KSOE.2013.27.2.059
Because of the recent increase in maritime cargo capacity, the production and price of crude oil have been rising. As oil prices have risen, many problems have occurred in the industry. To solve these problems, marine resources are being actively developed, and there has been an increase in the orders for special vessels and marine structures for the development of marine resources. However, consequently, various kinds of accidents have also occurred in these special vessels and structures. One of the major types of accidents involves fire and explosion, which cause many casualties and property damage. Therefore, various studies to estimate and prevent such accidents have been carried out. In this study, as basic research for the prevention of fire and explosion, numerical simulations on combustion were carried out by using a commercial grid generation program, Gridgen, and a CFD program, ANSYS-CFX. The influences of some parameters, such as the grid system, turbulence model, turbulent dissipation rate, and so on, on the simulation results were investigated, and optimum ones were chosen. It was found that the present results adopting these parameters agreed moderately well with other experimental and numerical ones.
Cyclic Crack Healing Effect of Al
Moon, Chang-Kwon ; Kim, Bu-Ahn ;
Journal of Ocean Engineering and Technology, volume 27, issue 2, 2013, Pages 69~74
DOI : 10.5574/KSOE.2013.27.2.069
In this study, the crack healing effects of
ceramics based on the heat treatment conditions were investigated. The influence of the additive amounts of SiC nanoparticles and the cycling process of indentation-heat treatment on the crack healing effect of
ceramics were also examined. Three-point bending tests were carried out and the morphological changes in the fracture surface were observed by using FE-SEM. As a result, heat-treated samples in a vacuum or air atmosphere showed improved bending strengths compared to un-heat treated samples. This means that cracked specimens can be healed by heat treatment in a vacuum or air atmosphere. The crack healing effect of
ceramics that were heat treated in an air atmosphere was much higher than that of those heat treated in a vacuum. After heat treatment, the
ceramics with 30 wt% SiC nanoparticles showed a higher bending strength than those with 15 wt% SiC. The cyclic indentation and heat treatment did not remarkably affect the crack healing effect. The SEM images showed that the median crack, indenter mark on the surface, and pores in the fracture surface of a specimen almost disappeared after being heat treated in an air atmosphere.
Effect of χ Phase on Impact Toughness of 25Cr-7Ni-2Mo-4W Super Duplex Stainless Steel
Namgung, Won ; Kang, Chang-Yong ;
Journal of Ocean Engineering and Technology, volume 27, issue 2, 2013, Pages 75~79
DOI : 10.5574/KSOE.2013.27.2.075
This study was carried out to investigate the precipitation behavior of the
phase and the impact toughness of 25%Cr-7%Ni-2%Mo-4%W super duplex stainless steel. The
phase was precipitated in the early stage of aging, and with the increasing aging time. However, after reaching a maximum value, the number decreased as a result of the gradual transformation of the
phase into the
-phase. It was proved that the
phase was an intermetallic compound, which represented a lower nickel concentration, higher chromium and molybdenum concentrations, and very higher tungsten concentration compared to the matrix phases. It also showed higher molybdenum and tungsten concentrations than the
phase. The decomposition of the ferrite phase into the
phases was retarded by W substitution for Mo. Thus, the number of
phases increased. The impact value was decreased by the substitution of W for Mo. The impact toughness rapidly decreased with time when the
phase began to precipitate in the initial stage of aging. The impact toughness was, therefore, greatly influenced for the precipitation of the
Driving Performance Simulation of Mining Robot for SMS deposits
Lee, Chang-Ho ; Kim, Hyung-Woo ; Hong, Sup ; Kim, Sung-Soo ;
Journal of Ocean Engineering and Technology, volume 27, issue 2, 2013, Pages 80~86
DOI : 10.5574/KSOE.2013.27.2.080
KIOST developed a deep-sea mining robot called "MineRo" to collect manganese nodules in 2007. MineRo operates on flat ground. SMS (seafloor massive sulfide) deposits are shaped like undulating mountains. This paper deals with a numerical analysis model of a mining robot for SMS deposits. The mining robot consists of a tracked vehicle, chassis structure with a turntable, boom arm with 2 articulations, excavation tool, discharging unit, hydro-electric system, and sensing-and-monitoring system. In order to compare and analyze the dynamic responses of the driving mechanism, various tracked vehicles are modeled using commercial software. Straight driving simulations are conducted under undulating ground conditions. A conceptual design of a mining robot with four track systems for SMS deposits is modeled on the basis of these results.
Study on Variation in Ship's Course Keeping Ability under Waves Depending on Rudder Type
Koo, Bonguk ; Lee, Jonghyun ; Kang, Donghoon ;
Journal of Ocean Engineering and Technology, volume 27, issue 2, 2013, Pages 87~92
DOI : 10.5574/KSOE.2013.27.2.087
The variation in the course keeping ability in relation to rudder type is investigated using simulations with 3 different types of rudders (a normal rudder, normal rudder with a plate, and Schilling rudder) under wave conditions. The simulation is developed based on an MMG model with Kijima's regression model, along with the data from Son's experiments and Kose's experiments. A 3-D source distribution method is applied to calculate the source of the external wave forces for the simulation. The coefficients of an autopilot controller that may affect the course keeping ability are also estimated from the simulations with the different rudders. The course keeping ability is evaluated by comparing the forward distances while the ships are simulated with the rudders and autopilot controller.
Development of Integrated Navigation Algorithm for Underwater Vehicle using Velocity Filter
Yoo, Tae-Suk ; Chung, Gyoo-Pil ; Yoon, Seon-Il ;
Journal of Ocean Engineering and Technology, volume 27, issue 2, 2013, Pages 93~99
DOI : 10.5574/KSOE.2013.27.2.093
This paper describes a robust algorithm for an integrated underwater navigation system based on VKF (velocity Kalman filter). The proposed approach relies on a VKF, augmented by the altitude from an echo-sounder-based switching architecture to yield robust performance, even when DVL (Doppler velocity log) exceeds the measurement range and the measured value cannot be valid. The proposed approach relies on three parts: 1) PINS (pure inertial navigation system), 2) VKF design, and 3) VKF-aided integrated navigation filter design. To evaluate the proposed method, we compare the results of the VKF-aided navigation system with the simulation result from a PINS and conventional INS-DVL method.
Design Study on Waterproof 4-axis Manipulator
Choi, Hyeung-Sik ; Jo, Jong-Rae ; Woo, Myoung-Man ; Seo, Jung-Min ; Ju, Young-Do ; Kang, Jung-Suk ;
Journal of Ocean Engineering and Technology, volume 27, issue 2, 2013, Pages 100~106
DOI : 10.5574/KSOE.2013.27.2.100
This paper deals with the design method for a small waterproof 4-axis robot arm. An extensive analysis was performed on the torque applied to the robot joint as a result of the payload, as well as the design of the joint actuator capacity. In addition, a study was undertaken on the design of a waterproof joint actuator that works at depths greater than 10 m and the wiring design for a small waterproof connector to avoid obstructing the robot motion. Finally, a finite element method simulation was carried out to analyze the strength of the designed robot arm link, and its stability was verified through a simulation test.
Experimental Investigation of Local Half-cone Scouring Against Dam under the Effect of Localized Vibrations in the Sediment Layers
Dodaran, Asgar Ahadpour ; Park, Sang Kil ; Mardashti, Asadollah ; Noshadi, Mehrzad ; Afsari, Mohammad ;
Journal of Ocean Engineering and Technology, volume 27, issue 2, 2013, Pages 107~113
DOI : 10.5574/KSOE.2013.27.2.107
Most natural river reach are approximately balanced with respect to sediment inflow and outflow. Dam construction dramatically alters this balance, creating an impounded river reach characterized by extremely low flow velocities and efficient sediment trapping. The impounded reach will accumulate sediment and lose storage capacity until a balance is again achieved, which would normally occur after the impoundment has become "filled up" with sediment and can no longer provide water storage and other benefits. This paper aims to investigate the sediment removal process in dam reservoir using simultaneously pressure flushing operation and vibrator machine. The main objective of this study is to identify the effect of vibrator in flushing cone dimensions. To achieve the objectives of present study, laboratory test have conducted under different hydraulic conditions such as two bottom outlets with diameter equal to 2" and 3", five discharges 0.23, 0.53, 1.21, 1.53 and 2.1 lit/s and only one water depth above the center of bottom outlets. Using the vibrator machine mounted into the reservoir and close to the bottom outlet, different frequency e.g. 20, 35 and 50 HZ, have been introduced to the deposited sediment at the vicinity of outlet. The results indicate that the volume and width of flushing cone are strongly affected by frequency of vibrations. The results indicate that the volume and width of flushing cone are strongly affected by frequency of vibrations.
Superhydrophobic Nano Patterning Techniques for Enhanced Performance of Naval Underwater Vessels
Hong, Soon-Kook ; Lee, Ki-Young ;
Journal of Ocean Engineering and Technology, volume 27, issue 2, 2013, Pages 114~120
DOI : 10.5574/KSOE.2013.27.2.114
A superhydrophobic surface means that the contact angle between the solid surface and a water droplet is more than
. Materials with a superhydrophobic surface have a self-cleaning function because of the Lotus effect, in which water is not absorbed by the material but rolls off of it. If such a Lotus effect can be applied to the surface of underwater vessels, submarines, torpedos, and so on, enhanced vessels can be made based on this lubricant effect reducing the friction coefficient for the liquid. Because polymer composites can be easily applied in various nanotechniques, they are more advantageous than conventional materials like iron in terms of a superhydrophobic surface. Furthermore, a superhydrophobic surface bring enhanced anticorrosion and ecotechnology because no paint is needed on underwater vessels.