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 2, Issue 4 - Dec 2010
Volume 2, Issue 3 - Sep 2010
Volume 2, Issue 2 - Jun 2010
Volume 2, Issue 1 - Mar 2010
Selecting the target year
Performance evaluation of an underwater body and pumpjet by model testing in cavitation tunnel
Suryanarayana, Ch. ; Satyanarayana, B. ; Ramji, K. ;
International Journal of Naval Architecture and Ocean Engineering, volume 2, issue 2, 2010, Pages 57~67
DOI : 10.3744/JNAOE.2010.2.2.057
Experimental investigations were carried out on an Axi-symmetric Body Model fitted with Pump-jet Propulsor (PJP) in the Cavitation Tunnel at Naval Science and Technological Laboratory (NSTL). The tests were intended for evaluating the propulsion characteristics of the body and propulsor. The self propulsion point of the model for two configurations was determined after finding the corrections for tunnel blockage effects and differences in model length at zero trim. The results were found to match closely with the towing tank results. The rotor and stator torques also matched closely over full range of experiment. Further experiments were carried out on the body at
angle of trim to investigate the propulsive performance and assess the operational difficulties in the sea. The results indicated an increase in resistance and decrease in rotor thrust; but the balance of torques between the rotor and stator was undisturbed, causing no concern to vehicle roll.
Predictive model for wave-induced currents and 3D beach evolution based on FAVOR Method
Kuroiwa, Masamitsu ; Abualtayef, Mazen ; Takada, Tetsushi ; Sief, Ahmed Khaled ; Matsubara, Yuehi ;
International Journal of Naval Architecture and Ocean Engineering, volume 2, issue 2, 2010, Pages 68~74
DOI : 10.3744/JNAOE.2010.2.2.068
The development of a numerical model using the fractional area/volume obstacle representation (FAVOR) method for predicting a nearshore current field bounded by complicated geometric shapes, and a three-dimensional (3D) beach evolution was described in this article. The 3D model was first tested against three cases to simulate the nearshore current fields around coastal structures, a river mouth, and a large scale cusp bathymetry. Then, the morphodynamic model tests, which are adopting the nearshore current model, were applied for the computations of beach evolution around a detached breakwater and two groins. It was confirmed that the presented model associated with the FAVOR method was useful to predict the nearshore current field in the vicinity of the complicated geometric shapes. Finally, the model was applied to a tombolo formation in a field site of Kunnui fishery port, which is located in Hokkaido, Japan.
Analytic study of a new conceptual propulsion device for ships
Muscia, Roberto ; Sciuto, Giacomo ;
International Journal of Naval Architecture and Ocean Engineering, volume 2, issue 2, 2010, Pages 75~86
DOI : 10.3744/JNAOE.2010.2.2.075
In this work the possibility of obtaining a rectilinear motion of bodies partially or totally submerged without using propellers is evaluated. The system propulsion is based on a pair of counter rotating masses that generate the thrust. The fluid-body system has been schematized in order to carry out a very simple model. Using this model an evaluation of the body motion along a longitudinal direction was performed. The motion equations of the system were written and integrated. The external forces applied to the body depend on its velocity in relation to the water. These forces were obtained by fluid dynamic simulations. Regarding the mechanical configuration suggested, the results obtained show that a certain displacement of the body along a fixed direction is obtainable.
Structural intensity analysis of a large container carrier under harmonic excitations of propulsion system
Cho, Dae-Seung ; Kim, Kyung-Soo ; Kim, Byung-Hwa ;
International Journal of Naval Architecture and Ocean Engineering, volume 2, issue 2, 2010, Pages 87~95
DOI : 10.3744/JNAOE.2010.2.2.087
The structural intensity analysis, which calculates the magnitude and direction of vibrational energy flow from vibratory velocity and internal force at any point of a structure, can give information on dominant transmission paths, positions of sources and sinks of vibration energy. This paper presents a numerical simulation system for structural intensity analysis and visualization to apply for ship structures based on the finite element method. The system consists of a general purpose finite element analysis program MSC/Nastran, its pre- and post-processors and an in-house program module to calculate structural intensity using the model data and its forced vibration analysis results. Using the system, the structural intensity analysis for a 4,100 TEU container carrier is carried out to visualize structural intensity fields on the global ship structure and to investigate dominant energy flow paths from harmonic excitation sources to superstructure at resonant hull girder and superstructure modes.
An approach to computerized preliminary design procedure of mid-size superyachts from hull modeling to interior space arrangement
Nam, Jong-Ho ; Kim, Dong-Ham ; Lee, Ho-Jin ;
International Journal of Naval Architecture and Ocean Engineering, volume 2, issue 2, 2010, Pages 96~103
DOI : 10.3744/JNAOE.2010.2.2.096
A concept of preliminary design for mid-size superyachts is explored. First, the profile of a superyacht is interactively designed with the help of freeform curve functionality and graphical user interface (GUI) based interaction. The hull form is then constructed using major characteristic curves such as design waterline, deck sideline, and sections in addition to the predefined profile curve. After exterior hull modeling is done, the arrangement of significant interior spaces of all decks is carried out. A genetic algorithm is exploited to find a space arrangement by considering space fitness values, space proximity, and stairs connectivity of relevant spaces. A goal of the paper is to offer a step-by-step procedure for superyacht design from scratch or when initial information is not sufficient for complete design. For this purpose, a GUI based superyacht design system is developed. This design approach is expected to help users interactively design mid-size superyachts.
A Numerical study for the efficacy of flow injection on the diminution of rudder cavitation
Seo, Dae-Won ; Lee, Seung-Hee ; Kim, Hyo-Chul ; Oh, Jung-Keun ;
International Journal of Naval Architecture and Ocean Engineering, volume 2, issue 2, 2010, Pages 104~111
DOI : 10.3744/JNAOE.2010.2.2.104
The complete avoidance of cavitation, as a result of gap flow between the fixed and movable portion of a horn type rudder system, is difficult. To reduce gap flow, it is a common practice to attach a half round prismatic bar that protrudes beyond the concave surface of the horn facing the gap and laid along the centerplane of the rudder. However the employment of such a device does not always yield satisfactory results. Previously, the authors have shown that a pair of blocking bars, attached on the convex surface of the movable portion, better enhance the blocking ability of gap flow to that of a single centre bar installed on the concave surface. This also circumvents difficulties that might occur in practical applications. In the present study, a series of numerical computations show that flow injected into the gap of a rudder may also block the flow within, without employment of any physical devices, such as a half circular bar. This study also shows that the combination of flow injection and blocking bars may result in the synergic augmentation of blocking efficiency of gap flow, as demonstrated in computations for a three dimensional rudder system.
Numerical investigation of vortex shedding and vortex-induced vibration for flexible riser models
Chen, Zheng-Shou ; Kim, Wu-Joan ;
International Journal of Naval Architecture and Ocean Engineering, volume 2, issue 2, 2010, Pages 112~118
DOI : 10.3744/JNAOE.2010.2.2.112
The numerical study about the vortex-induced vibration and vortex shedding in the wake has been presented. Prior to the numerical simulation of flexible riser systems concerning engineering conditions, efficiency validating of the proposed FSI solution method have been performed. The comparison between numerical simulation and published experimental data shows that the CFD method designed for FSI solution could give acceptable result for the VIV prediction of flexible riser/pipe system. As meaningful study on VIV and vortex shedding mode with the focus on flexible riser model systems, two kinds of typical simulation cases have been carried out. One was related to the simulation of vortex visualization in the wake for a riser model subject to forced oscillation, and another was related to the simulation of fluid-structure interaction between the pipes of coupled multi-assembled riser system. The result from forced oscillation simulation shows that the vortex-induced vibration with high response frequency but small instantaneous vibration amplitude contributes to vortex conformation as much as the forced oscillation with large normalized amplitude does, when the frequency of forced oscillation was relatively high. In the multi-assembled riser systems, it has been found that the external current velocity and the distance between two pipes are the critical factors to determine the vibration state and the steady vibration state emerging in quad-pipe system may be destroyed more easily than dual-pipe system.