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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 28, Issue 6 - Dec 2014
Volume 28, Issue 5 - Oct 2014
Volume 28, Issue 4 - Aug 2014
Volume 28, Issue 3 - Jun 2014
Volume 28, Issue 2 - Apr 2014
Volume 28, Issue 1 - Feb 2014
Selecting the target year
Comparative Study between Results of Theoretical Calculation and Model Test for Performance Confirmation of "Crown Duct"
Lee, Kwi-Joo ; An, Jung-Sun ; Kwak, Han-Joung ;
Journal of Ocean Engineering and Technology, volume 28, issue 1, 2014, Pages 1~5
DOI : 10.5574/KSOE.2014.28.1.001
Chosun University, in cooperation with SPP shipyard, has developed an energy saving device based on a new concept: "Crown Duct." Crown Duct is composed of a semi-duct with short struts inside and outside the duct. Theoretical calculations for two different designs were carried out using the CFD code "Ship Flow." The design selected from these two different forms by the CFD code analysis was tested in a towing tank at SSPA. The results showed about 4% efficiency gain under a full-load condition and about 7% gain under a ballast condition in the towing tank test.
Experimental Study of Wave Run-up on Semi-submersible Offshore Structures in Regular Waves
Kim, Namwoo ; Nam, Bo Woo ; Cho, Yoonsang ; Sung, Hong Gun ; Hong, Sa Young ;
Journal of Ocean Engineering and Technology, volume 28, issue 1, 2014, Pages 6~11
DOI : 10.5574/KSOE.2014.28.1.006
This paper presents the results of an experimental study of wave run-ups on a semi-submersible offshore structure. A series of model tests with a 1:80 scale ratio were carried out in the two-dimensional wave basin of MOERI/KIOST. The experimental model had two columns and one pontoon. The model was fixed and wave elevations were measured at five points per column. Two different draft (operational & survival) conditions and three wave heights were considered under regular wave conditions. First, the nonlinear characteristics of wave run-ups are discussed by using the time series data. Then, the wave heights are compared with numerical results based on the potential flow model. The comparison shows fairly good correlation between the experiments and computations. Finally, wave run-ups under the operational and survival conditions are suggested.
Two-Dimensional Particle Simulation for Behaviors of Floating Body near Quaywall during Tsunami
Park, Ji-In ; Park, Jong-Chun ; Hwang, Sung-Chul ; Heo, Jae-Kyung ;
Journal of Ocean Engineering and Technology, volume 28, issue 1, 2014, Pages 12~19
DOI : 10.5574/KSOE.2014.28.1.012
Tsunamis are ocean waves generated by movements of the Earth's crust. Several geophysical events can lead to this kind of catastrophe: earthquakes, landslides, volcanic eruptions, and other mechanisms such as underwater explosions. Most of the damage associated with tsunamis are related to their run-up onto the shoreline. Therefore, effectively predicting the run-up process is an important aspect of any seismic sea wave mitigation effort. In this paper, a numerical simulation of the behaviors of a floating body near a quaywall during a tsunami is conducted by using a particle method. First, a solitary wave traveling over shallow water with a slope is numerically simulated, and the results are compared with experiments and other numerical results. Then, the behaviors of floating bodies with different drafts are investigated numerically.
Development of Slender Doubler Plate Hybrid Design System for Ship Structure Subjected to Longitudinal In-plane Compression
Ham, Juh-Hyeok ;
Journal of Ocean Engineering and Technology, volume 28, issue 1, 2014, Pages 20~27
DOI : 10.5574/KSOE.2014.28.1.020
In view of the importance of material reduction and rational structural design due to the rapid increase in oil and steel prices, an optimized structural hybrid design system for the doubler plate of a ship's hull structure was developed. A direct design process by a structural designer was added to this developed optimized system to increase the design efficiency and provide a way of directly inserting a designer's decisions into the design system process. As the first step of the doubler design system development, the design formulas used in doubler design system were introduced. Based on the introduction of influence coefficients
according to the variations in the doubler length, breadth, doubler thickness, and average corrosion thickness of the main plate, the design formulas for an equivalent plate thickness were developed, and a hybrid design system using these formulas was suggested for the slender doubler plate of a ship structure subjected to a longitudinal in-plane compression load. By using this developed design system, a more rational doubler plate design can be expected considering the efficient reinforcement of the plate members of ship structures. Additionally, a more detailed structural analysis through local strength evaluations will be performed to verify the efficiency of the optimum structural design for the doubler plate.
Comparative Study of Ice Breaking Performance according to Scale of Sea Ice on Ice Field
Lee, Chun-Ju ; Kim, Hyun Soo ; Choi, Kyungsik ;
Journal of Ocean Engineering and Technology, volume 28, issue 1, 2014, Pages 28~33
DOI : 10.5574/KSOE.2014.28.1.028
The Korean icebreaking research vessel "Araon" performed four sea trials in the Arctic and Antarctic Seas. The ice properties, such as the ice thickness, floe size, ice strength, and power of the vessel were quite different in these trials. To compare the speeds of ship with the same ice strength and power, the AARC (Arker Arctic Research Center) method is used with a vessel power of 10 MW and an ice strength of 630 Pa in this paper. Based on the analysis results, the speed of the ship was 1.62 knots (0.83 m/s) with a 1.02-m ice thickness and 2.5-km floe size, 5.3 knots (2.73 m/s) with a 1.2-m ice thickness and 1.0-km floe size, and 13.8 knots (7.10 m/s) with a 1.1-m ice thickness and 200-m floe size. The analysis results showed that the ship speed and floe size have an inversely proportional relationship. Two reasonable reasons are given in this paper for the final result. One is an ice breaking phenomenon, and the other is the effect of the ice floe mass. For the breaking phenomenon, the ice breaking force is very small because the ice floe is not breaking but tearing when a ship is passing through a small ice floe. Regarding the effect of the ice floe mass, it is impossible for a ship to push and tear an ice floe if the mass of the ice floe is too large compared to the mass of the ship. The velocity of the ship decreases when the ice floe has a large mass and a large size because the ship has to break the ice floe to move forward.
Fracture Simulation of Low-Temperature High-Strength Steel (EH36) using User-Subroutine of Commercial Finite Element Code
Choung, Joonmo ; Nam, Woongshik ; Kim, Younghun ;
Journal of Ocean Engineering and Technology, volume 28, issue 1, 2014, Pages 34~46
DOI : 10.5574/KSOE.2014.28.1.034
This paper discusses a new formulation for the failure strain in the average stress triaxiaility domain for a low-temperature high-strength steel (EH36). The new formula available at a low average stress triaxiality zone is proposed based on the comparison of two results from tensile tests of flat type specimens and their numerical simulations. In order to confirm the validity of the failure strain formulation, a user-subroutine was developed using Abaqus/Explicit, which is known to be one of the most popular commercial finite element analysis codes. Numerical fracture simulations with the user-subroutine were conducted for all the tensile tests. A comparison of the engineering stress-strain curves and engineering failure strain obtained from the numerical simulation with the user-subroutine for the tensile tests revealed that the newly developed user-subroutine effectively predicts the initiation of failure.
Evaluation of Behaviors on Mooring Line Embedded in Sand Using Centrifuge Test
Lee, Hoon Yong ; Kim, Surin ; Kim, Jaehyun ; Kim, Dong-Soo ; Choo, Yun Wook ; Kwo, Osoon ;
Journal of Ocean Engineering and Technology, volume 28, issue 1, 2014, Pages 47~54
DOI : 10.5574/KSOE.2014.28.1.047
When an anchor penetrates and is installed under a seabed, a portion of the mooring line connected to the anchor is also embedded under the seabed. This embedded mooring line affects the capacity of the anchor in two ways. First, the frictional resistance that occurs between the mooring line and the seabed reduces the pulling force acting on the anchor. Second, the embedded part of the mooring line forms a reverse catenary shape due to the bearing resistance of the soil, so that an inclined pulling force is applied to the anchor. To evaluate the mooring line's effect on the capacity of an anchor in sand, centrifuge model tests were performed using two relative sand densities of 76% and 51% while changing the anchor depths. The test results showed that the load is reduced much more in deep and dense sand, and the inclination angle of the load is lower in shallow and loose sand.
Sub-bottom Profiling Algorithm using Parametric Array
Lee, Chong Hyun ; Lee, Jaeil ; Bae, Jinho ;
Journal of Ocean Engineering and Technology, volume 28, issue 1, 2014, Pages 55~63
DOI : 10.5574/KSOE.2014.28.1.055
In this paper, we propose an threshold-based Schur algorithm for estimating the media characteristics of sub-bottom multi-layers by using the signal generated by a parametric array transducer. We use the KZK model to generate a parametric array signal, and use the proposed threshold-based Schur algorithm for estimating the reflection coefficients of multiple sea bottom layers. Using computer simulation, we verify that the difference frequency component generated by the KZK model prevails over the signals of primary frequencies at long range. For the simulation, we use the transmit signal generated by the KZK and the reflected signal obtained from a lattice filter model for the seawater and sub-bottom of multi-level non-homogeneous layers. Through the simulation, we verify that the proposed threshold-based Schur algorithm can give much more accurate and efficient estimates of the reflection coefficients than methods using received signal, matched filter output signal, and normal Schur algorithm output.
Nanoparticle Effect on Durability of Carbon fiber/Epoxy Composites in Saline Water Environment
Kim, Bu-Ahn ; Moon, Chang-Kwon ;
Journal of Ocean Engineering and Technology, volume 28, issue 1, 2014, Pages 64~68
DOI : 10.5574/KSOE.2014.28.1.064
This study was conducted to investigate the durability of carbon fiber/epoxy composites (CFRP) in a saline water environment. The carbon fiber/epoxy composites were modified to use nanoparticles such as carbon nanotubes and titanum oxide. These hybrid composites were exposed to a saline water environment for a certain period. The weight gain according to the immersion time, a quasi-static tensile test, and micro-graphic characterization were used to investigate the samples exposed to the saline water environment. The weight gains increased with increasing immersion time. The weight gains of the hybrid composites were lower than that for pure CFRP throughout the entire immersion time. The tensile strengths decreased with increasing immersion time. The tensile strengths of the hybrid composites were higher than that of the pure CFRP throughout the entire immersion time. The pure CFRP was observed to be more degraded than the hybrid composites in the saline water environment. Therefore, it was concluded that the addition of nanoparticles to CFRP could lead to improved durability in a saline water environment.
Integrated survivability assessment given multiple penetration hits
Kim, Kwang-Sik ; Lee, Jang-Hyun ;
Journal of Ocean Engineering and Technology, volume 28, issue 1, 2014, Pages 69~76
DOI : 10.5574/KSOE.2014.28.1.069
Survivability assessments and vulnerability reductions are required in warship design. A warship's survivability is assessed by its susceptibility, vulnerability, and recoverability. In this paper, an integrated survivability assessment for a warship subjected to multiple hits is introduced. The methodology aims at integrating a survivability assessment into an early stage of warship design. The hull surface is idealized using typical geometries for RCS (Radar Cross Section) detection probability and susceptibility. The Vulnerability is evaluated by using the shot-line. The recoverability is estimated using a survival time analysis. This enables the variation of survivability to be assessed. Several parameters may be varied to determine their effects on the survivability. The susceptibility is assessed by the probability of detecting the radar cross section of the subject and the probability of being hit based on a probability density function. The vulnerability is assessed by the kill probability based on the vulnerable area of critical components, according to the component's layout and redundancy. Recoverability is assessed by the recovery time for damaged critical components.
Comparative Study of Rules of ISO 12215 and International Classification Society for Structural Design of CFRP Cruise Boat
Oh, Dae-Kyun ; Lee, Dong-Kun ; Kang, Gi-Moon ; Ryu, Cheol-Ho ; Noh, Jackyou ;
Journal of Ocean Engineering and Technology, volume 28, issue 1, 2014, Pages 77~84
DOI : 10.5574/KSOE.2014.28.1.077
Recently, CFRP composites have often been used as the materials for lightweight pleasure yacht hulls. Because CFRP composites not only make the hull light but also have good physical characteristics, in the leading countries of the marine industries, CFRP yachts are being sold at a higher price. The design and construction of FRP composite yachts, including those made of CFRP, have to follow rules based on ISO 12215, such as the hull structure rules of the international classification societies. On the other hand, there are no rules related to CFRP composites in the Guidance for Recreational Crafts, which was newly revised by the Korean Register of Shipping. In this paper, ISO 12215-5 and Part B, RINA Pleasure Yacht (REGISTRO ITALIANO NAVALE) on the design pressure and scantling of CFRP hull structures are compared and analyzed. Through a comparative study and the application to a cruise yacht design, we try to understand how to design CFRP hull structures using the international standards, ISO 12215, and the rules of the international classification society, RINA.
Trend and Review of Corrosion Resistant Alloy (CRA) for Offshore Pipeline Engineering
Yu, Su-Young ; Choi, Han-Suk ; Lee, Seung-Keon ; Kim, Do-Kyun ;
Journal of Ocean Engineering and Technology, volume 28, issue 1, 2014, Pages 85~92
DOI : 10.5574/KSOE.2014.28.1.085
Offshore fields are increasingly important for the development of offshore resources due to the growing energy needs. However, an offshore field for oil and gas production has difficult development conditions, e.g., high temperature, high pressure, sweet/sour compositions of fluids, etc. Corrosion is one of the biggest issues for offshore pipeline engineering. In this study, a Corrosion Resistant Alloy (CRA) pipe for corrosion prevention was investigated through its global demand and trends, and three types of CRA pipelines were introduced with detailed explanations. The usefulness of CRA was also evaluated in comparison to a carbon steel pipeline in terms of the structural strength, cost, and other factors. Offshore pipeline engineering, including mechanical design and verification of the results through an installation analysis based on numerical software, was performed for the carbon steel type and solid CRA type. The results obtained from this study will be useful data for CRA pipeline designers and researchers.