Go to the main menu
Skip to content
Go to bottom
REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
> Journal Vol & Issue
International Journal of Naval Architecture and Ocean Engineering
Journal Basic Information
Journal DOI :
The Society of Naval Architects of Korea
Editor in Chief :
Volume & Issues
Volume 4, Issue 4 - Dec 2012
Volume 4, Issue 3 - Sep 2012
Volume 4, Issue 2 - Jun 2012
Volume 4, Issue 1 - Mar 2012
Selecting the target year
Experimental study on dynamic buckling phenomena for supercavitating underwater vehicle
Chung, Min-Ho ; Lee, Hee-Jun ; Kang, Yeon-Cheol ; Lim, Woo-Bin ; Kim, Jeong-Ho ; Cho, Jin-Yeon ; Byun, Wan-Il ; Kim, Seung-Jo ; Park, Sung-Han ;
International Journal of Naval Architecture and Ocean Engineering, volume 4, issue 3, 2012, Pages 183~198
DOI : 10.3744/JNAOE.2012.4.3.183
Dynamic buckling, also known as parametric resonance, is one of the dynamic instability phenomena which may lead to catastrophic failure of structures. It occurs when compressive dynamic loading is applied to the structures. Therefore it is essential to establish a reliable procedure to test and evaluate the dynamic buckling behaviors of structures, especially when the structure is designed to be utilized in compressive dynamic loading environment, such as supercavitating underwater vehicle. In the line of thought, a dynamic buckling test system is designed in this work. Using the test system, dynamic buckling tests including beam, plate, and stiffened plate are carried out, and the dynamic buckling characteristics of considered structures are investigated experimentally as well as theoretically and numerically.
A study on ship automatic berthing with assistance of auxiliary devices
Tran, Van Luong ; Im, Nam-Kyun ;
International Journal of Naval Architecture and Ocean Engineering, volume 4, issue 3, 2012, Pages 199~210
DOI : 10.3744/JNAOE.2012.4.3.199
The recent researches on the automatic berthing control problems have used various kinds of tools as a control method such as expert system, fuzzy logic controllers and artificial neural network (ANN). Among them, ANN has proved to be one of the most effective and attractive options. In a marine context, the berthing maneuver is a complicated procedure in which both human experience and intensive control operations are involved. Nowadays, in most cases of berthing operation, auxiliary devices are used to make the schedule safer and faster but none of above researches has taken into account. In this study, ANN is applied to design the controllers for automatic ship berthing using assistant devices such as bow thruster and tug. Using back-propagation algorithm, we trained ANN with set of teaching data to get a minimal error between output values and desired values of four control outputs including rudder, propeller revolution, bow thruster and tug. Then, computer simulations of automatic berthing were carried out to verify the effectiveness of the system. The results of the simulations showed good performance for the proposed berthing control system.
Implementation of the submarine diving simulation in a distributed environment
Ha, Sol ; Cha, Ju-Hwan ; Roh, Myung-Il ; Lee, Kyu-Yeul ;
International Journal of Naval Architecture and Ocean Engineering, volume 4, issue 3, 2012, Pages 211~227
DOI : 10.3744/JNAOE.2012.4.3.211
To implement a combined discrete event and discrete time simulation such as submarine diving simulation in a distributed environment, e.g., in the High Level Architecture (HLA)/Run-Time Infrastructure (RTI), a HLA interface, which can easily connect combined models with the HLA/RTI, was developed in this study. To verify the function and performance of the HLA interface, it was applied to the submarine dive scenario in a distributed environment, and the distributed simulation shows the same results as the stand-alone simulation. Finally, by adding a visualization model to the simulation and by editing this model, we can confirm that the HLA interface can provide user-friendly functions such as adding new model and editing a model.
Application of morphing technique with mesh-merging in rapid hull form generation
Kang, Ju-Young ; Lee, Byung-Suk ;
International Journal of Naval Architecture and Ocean Engineering, volume 4, issue 3, 2012, Pages 228~240
DOI : 10.3744/JNAOE.2012.4.3.228
Morphing is a geometric interpolation technique that is often used by the animation industry to transform one form into another seemingly seamlessly. It does this by producing a large number of 'intermediate' forms between the two 'extreme' or 'parent' forms. It has already been shown that morphing technique can be a powerful tool for form design and as such can be a useful addition to the armoury of product designers. Morphing procedure itself is simple and consists of straightforward linear interpolation. However, establishing the correspondence between vertices of the parent models is one of the most difficult and important tasks during a morphing process. This paper discusses the mesh-merging method employed for this process as against the already established mesh-regularising method. It has been found that the merging method minimises the need for manual manipulation, allowing automation to a large extent.
Numerical and experimental investigation on the performance of three newly designed 100 kW-class tidal current turbines
Song, Mu-Seok ; Kim, Moon-Chan ; Do, In-Rok ; Rhee, Shin-Hyung ; Lee, Ju-Hyun ; Hyun, Beom-Soo ;
International Journal of Naval Architecture and Ocean Engineering, volume 4, issue 3, 2012, Pages 241~255
DOI : 10.3744/JNAOE.2012.4.3.241
Three types of 100 kW-class tidal stream turbines are proposed and their performance is studied both numerically and experimentally. Following a wind turbine design procedure, a base blade is derived and two additional blades are newly designed focusing more on efficiency and cavitation. For the three designed turbines, a CFD is performed by using FLUENT. The calculations predict that the newly designed turbines perform better than the base turbine and the tip vortex can be reduced with additional efficiency increase by adopting a tip rake. The performance of the turbines is tested in a towing tank with 700 mm models. The scale problem is carefully investigated and the measurements are compared with the CFD results. All the prediction from the CFD is supported by the model experiment with some quantitative discrepancy. The maximum efficiencies are 0.49 (CFD) and 0.45 (experiment) at TSR 5.17 for the turbine with a tip rake.
Numerical simulation of cavitating flow past axisymmetric body
Kim, Dong-Hyun ; Park, Warn-Gyu ; Jung, Chul-Min ;
International Journal of Naval Architecture and Ocean Engineering, volume 4, issue 3, 2012, Pages 256~266
DOI : 10.3744/JNAOE.2012.4.3.256
Cavitating flow simulation is of practical importance for many engineering systems, such as marine propellers, pump impellers, nozzles, torpedoes, etc. The present work has developed the base code to solve the cavitating flows past the axisymmetric bodies with several forebody shapes. The governing equation is the Navier-Stokes equation based on homogeneous mixture model. The momentum is in the mixture phase while the continuity equation is solved in liquid and vapor phase, separately. The solver employs an implicit preconditioning algorithm in curvilinear coordinates. The computations have been carried out for the cylinders with hemispherical, 1-caliber, and 0-caliber forebody and, then, compared with experiments and other numerical results. Fairly good agreements with experiments and numerical results have been achieved. It has been concluded that the present numerical code has successfully accounted for the cavitating flows past axisymmetric bodies. The present code has also shown the capability to simulate ventilated cavitation.
Free vibration analysis of rectangular plate with arbitrary edge constraints using characteristic orthogonal polynomials in assumed mode method
Kim, Kook-Hyun ; Kim, Byung-Hee ; Choi, Tae-Muk ; Cho, Dae-Seung ;
International Journal of Naval Architecture and Ocean Engineering, volume 4, issue 3, 2012, Pages 267~280
DOI : 10.3744/JNAOE.2012.4.3.267
An approximate method based on an assumed mode method has been presented for the free vibration analysis of a rectangular plate with arbitrary edge constraints. In the presented method, natural frequencies and their mode shapes of the plate are calculated by solving an eigenvalue problem of a multi-degree-of-freedom system matrix equation derived by using Lagrange's equations of motion. Characteristic orthogonal polynomials having the property of Timoshenko beam functions which satisfies edge constraints corresponding to those of the objective plate are used. In order to examine the accuracy of the proposed method, numerical examples of the rectangular plates with various thicknesses and edge constraints have been presented. The results have shown good agreement with those of other methods such as an analytic solution, an approximate solution, and a finite element analysis.
Hydrodynamic analysis of a floating body with an open chamber using a 2D fully nonlinear numerical wave tank
Uzair, Ahmed Syed ; Koo, Weon-Cheol ;
International Journal of Naval Architecture and Ocean Engineering, volume 4, issue 3, 2012, Pages 281~290
DOI : 10.3744/JNAOE.2012.4.3.281
Hydrodynamic analysis of a surface-piercing body with an open chamber was performed with incident regular waves and forced-heaving body motions. The floating body was simulated in the time domain using a 2D fully nonlinear numerical wave tank (NWT) technique based on potential theory. This paper focuses on the hydrodynamic behavior of the free surfaces inside the chamber for various input conditions, including a two-input system: both incident wave profiles and forced body velocities were implemented in order to calculate the maximum surface elevations for the respective inputs and evaluate their interactions. An appropriate equivalent linear or quadratic viscous damping coefficient, which was selected from experimental data, was employed on the free surface boundary inside the chamber to account for the viscous energy loss on the system. Then a comprehensive parametric study was performed to investigate the nonlinear behavior of the wave-body interaction.
Estimation of geometry-based manufacturing cost of complex offshore structures in early design stage
Nam, Jong-Ho ; Sohn, Se-Hwan ; Singer, David J. ;
International Journal of Naval Architecture and Ocean Engineering, volume 4, issue 3, 2012, Pages 291~301
DOI : 10.3744/JNAOE.2012.4.3.291
A scalar metric for the assessment of hull surface producibility was known to be useful in estimating the complexity of a hull form of ships or large offshore structures by looking at their shape. However, it could not serve as a comprehensive measuring tool due to its lack of important components of the hull form such as longitudinals, stiffeners, and web frames attached to the hull surface. To have a complete metric for cost estimation, these structural members must be included. In this paper, major inner structural members are considered by measuring the complexity of their geometric shape. The final scalar metric thus consists of the classes containing inner members with various curvature magnitudes as well as the classes containing curved plates with single and double curvature distribution. Those two distinct metrics are merged into a complete scalar metric that accounts for the total cost estimation of complex structural bodies.
Study on the pressure self-adaptive water-tight junction box in underwater vehicle
Huang, Haocai ; Ye, Yanying ; Leng, Jianxing ; Yuan, Zhuoli ; Chen, Ying ;
International Journal of Naval Architecture and Ocean Engineering, volume 4, issue 3, 2012, Pages 302~312
DOI : 10.3744/JNAOE.2012.4.3.302
Underwater vehicles play a very important role in underwater engineering. Water-tight junction box (WJB) is one of the key components in underwater vehicle. This paper puts forward a pressure self-adaptive water-tight junction box (PSAWJB) which improves the reliability of the WJB significantly by solving the sealing and pressure problems in conventional WJB design. By redundancy design method, the pressure self-adaptive equalizer (PSAE) is designed in such a way that it consists of a piston pressure-adaptive compensator (PPAC) and a titanium film pressure-adaptive compensator (TFPAC). According to hydro-mechanical simulations, the operating volume of the PSAE is more than or equal to 11.6 % of the volume of WJB liquid system. Furthermore, the required operating volume of the PSAE also increases as the gas content of oil, hydrostatic pressure or temperature difference increases. The reliability of the PSAWJB is proved by hyperbaric chamber tests.
A simplified geometric stiffness in stability analysis of thin-walled structures by the finite element method
Senjanovic, Ivo ; Vladimir, Nikola ; Cho, Dae-Seung ;
International Journal of Naval Architecture and Ocean Engineering, volume 4, issue 3, 2012, Pages 313~321
DOI : 10.3744/JNAOE.2012.4.3.313
Vibration analysis of a thin-walled structure can be performed with a consistent mass matrix determined by the shape functions of all degrees of freedom (d.o.f.) used for construction of conventional stiffness matrix, or with a lumped mass matrix. In similar way stability of a structure can be analysed with consistent geometric stiffness matrix or geometric stiffness matrix with lumped buckling load, related only to the rotational d.o.f. Recently, the simplified mass matrix is constructed employing shape functions of in-plane displacements for plate deflection. In this paper the same approach is used for construction of simplified geometric stiffness matrix. Beam element, and triangular and rectangular plate element are considered. Application of the new geometric stiffness is illustrated in the case of simply supported beam and square plate. The same problems are solved with consistent and lumped geometric stiffness matrix, and the obtained results are compared with the analytical solution. Also, a combination of simplified and lumped geometric stiffness matrix is analysed in order to increase accuracy of stability analysis.
Hydrodynamic characteristics of X-Twisted rudder for large container carriers
Ahn, Kyoung-Soo ; Choi, Gil-Hwan ; Son, Dong-Igk ; Rhee, Key-Pyo ;
International Journal of Naval Architecture and Ocean Engineering, volume 4, issue 3, 2012, Pages 322~334
DOI : 10.3744/JNAOE.2012.4.3.322
This paper shows the numerical and experimental results about the hydrodynamic characteristics of X-Twisted rudders having continuous twist of the leading edge along the span. All the results were compared with those of the semi-balanced rudder. Calculation through the Reynolds-Averaged Navier-Stokes Equation (RANSE) code with propeller sliding meshes shows large inflow angle and fast inflow velocity in the vicinity of
R from the shaft center, so it may cause cavitation. Also, X-Twisted rudder has relatively small inflow angles along the rudder span compared with semi-balanced rudder. For the performance validation, rudders for two large container carriers were designed and tested. Cavitation tests at the medium sized cavitation tunnel with respect to the rudder types and twisted angles showed the effectiveness of twist on cavitation and the tendency according to the twist. And the resistance, self-propulsion and manoeuvring tests were also carried out at the towing tank. As a result, in the case of X-Twisted rudder, ship speed was improved with good manoeuvring performance. Especially, it was found out that manoeuvring performance between port and starboard was well balanced compared with semi-balanced rudders.