Seasickness prediction in passenger ships at the design stage     

F.L. Prez Arribas  A. Lpez Pieiro 《Ocean Engineering》2007,34(14-15):2086-2092

Seakeeping qualities are one of the most important aspects for passenger ships, since a collateral effect of seakeeping, the seasickness, can avoid the use of ships and ferries among passengers who can choose a different way of transport. Therefore, it is important for ship designers and ship owners to predict and evaluate the seasickness effects at the design stage.In this paper, a review of the seasickness causes and effects is made, and a mathematical model that includes several human factors is proposed. This model is applicable especially in big passenger ships where different kind of spaces or activities for the passengers can be found inside the ship.The way to present the large amount of information obtained in seakeeping calculations is important, and it is useful to detect the most conflictive parts of the ship's general arrangement. Calculations for an example ferry are presented.  相似文献   

Energy conservation during grounding with rigid slopes     

A. Glykas  P. K. Das 《Ocean Engineering》2001,28(4)

In this paper a numerical approach to the grounding problem takes place. It aims to show the contribution of the energy dissipated in the structure due to elasto-plastic deformation. The analytical methods developed until now, neglect this amount of energy, since they are simulating the vessel as a rigid beam. A tanker vessel is modelled with the Finite Element Package ABAQUS and energy conservation during a grounding scenario on rigid slope takes place. The results are presented both analytically and numerically and comparison in the energy quantities is shown and discussed.  相似文献   

Energy conservation during a tanker collision     

A. Glykas  P. K. Das 《Ocean Engineering》2001,28(4):2

The energy dissipation on the bow structure is calculated during a “head-on” collision with a rigid body, using finite element analysis. Gerard's method (Gerard, G., 1958. The crippling strength of compression elements. Journal of the Aeronautical Sciences), an empirical approach, is compared with the results produced by ABAQUS in terms of velocity, energy and penetrating distance. The energy conservation theorem is applied and the contribution of all individual structural members in terms of elastic and plastic energy is calculated. The strain distribution is shown for those members responsible for the water tightness and structural integrity of the structure. The global bending of the upper part of the bow is shown as well as the effect of the total ship mass inertia, phenomena which have not been incorporated into Gerard's approach ( Gerard, 1958). The final time of rest predicted from both methods is compatible and this validates the reliability of the numerical approach.  相似文献   

Dynamic analysis of vehicle–deck interactions     

Junbo Jia  Anders Ulfvarson 《Ocean Engineering》2006,33(13):1765-1795

This paper presents the review and studies at various levels of problems concerning the authors’ previous research on the dynamics of vehicle–deck interactions. The various levels of study include the dynamic structural behavior of vehicle–deck systems, vehicle vibrations, damping effects of vehicles on structural systems, dynamic interactions between tire and deck surface, and vehicle securing on decks during ship motions, etc. The study includes analytical, numerical and experimental analysis. Practical problems encountered by Ro–Ro ship designers are addressed by discussing those analysis. It is shown that influences from the dynamics of vehicle–deck interactions are relevant to a number of aspects of issues, such as the excitation frequency range, how detailed information of the structural system response is required, the structure characteristics, and positions and orientations of vehicles on decks, etc. The study contributes to the knowledge for the naval architect and vehicle engineer on how significant the dynamics of vehicle–deck interactions are when dealing with relevant problems.  相似文献   

Three-dimensional hydrodynamic model, study cases for quarter annular and idealized ship channel problems     

W. W. Pandoe  B. L. Edge 《Ocean Engineering》2003,30(9):1117-1135

An extended version of the three-dimensional hydrodynamic model, ADCIRC 3D-DSS, was utilized to simulate both horizontal and vertical flows in a (quarter) annular harbor (QATP and ATP) and rectangular basin with an idealized ship channel (RBSC). Comparison of horizontal and vertical solutions to the analytical solution and results of other researchers are in good agreement. The vertical velocity solution is highly sensitive to the horizontal velocity solutions. The presence of the sidewall boundary may also affect the vertical solutions. Around the sloping bank of RBSC channel with one-third gradient, the vertical velocity becomes important. The maximum vertical velocity approaches ±50% of the sediment fall velocity of fine sand.  相似文献   

On unstable ship motions resulting from strong non-linear coupling   总被引：1，自引：0，他引：1  

Marcelo A.S. Neves  Claudio A. Rodríguez 《Ocean Engineering》2006,33(14-15):1853-1883

In this paper, the modelling of strong parametric resonance in head seas is investigated. Non-linear equations of ship motions in waves describing the couplings between heave, roll and pitch are contemplated. A third-order mathematical model is introduced, aimed at describing strong parametric excitation associated with cyclic changes of the ship restoring characteristics. A derivative model is employed to describe the coupled restoring actions up to third order. Non-linear coupling coefficients are analytically derived in terms of hull form characteristics.The main theoretical aspects of the new model are discussed. Numerical simulations obtained from the derived third-order non-linear mathematical model are compared to experimental results, corresponding to excessive motions of the model of a transom stern fishing vessel in head seas. It is shown that this enhanced model gives very realistic results and a much better comparison with the experiments than a second-order model.  相似文献   

Modification of ship hydrodynamic interaction forces and moment by underwater ship geometry   总被引：1，自引：0，他引：1  

K.S. Varyani  P. Krishnankutty 《Ocean Engineering》2006,33(8-9):1090-1104

The hydrodynamic interaction forces/moments acting on a moored ship due to the passage of another ship in its proximity is researched by considering the influence of ship form against the idealized approach of the use of parabolic sectional area distribution. Comparisons with experimental results show that the interaction effects are predicted better by inclusion of ship's form.  相似文献   

Theoretical and experimental study on dynamic behavior of a damaged ship in waves     

Dongkon Lee  S.Y. Hong  G.-J. Lee 《Ocean Engineering》2007,34(1):21-31

Most of the large scaled casualties are caused by loss of structural strength and stability due to the progressive flooding and the effect of waves and wind. To prevent foundering and structural failure, it is necessary to predict the motion of the damaged ship in waves.This paper describes the motion of damaged ship in waves resulting from a theoretical and experimental study. A time domain theoretical model, which can be applied to any type of ship or arrangement, for the prediction of damaged ship motion and accidental flooding has been developed considering the effects of flooding of compartments. To evaluate the accuracy of the model, model tests are carried out in ship motion basin for three different damaged conditions: engine room bottom damage, side shell damage and bow visor damage of Ro–Ro ship in regular and irregular waves with different wave heights and directions.  相似文献   

Application of wave model for weather routing of ships in the North Indian Ocean   总被引：1，自引：1，他引：0  

Chinmaya Prasad Padhy  Debabrata Sen  Prasad Kumar Bhaskaran 《Natural Hazards》2008,44(3):373-385

Weather routing of ships is used to establish the shortest time route or the most economical route from a departure to arrival point by applying available information of the weather condition viz. wind, wave and current. Information on ship speed loss due to these effects is pre-computed using sea-keeping computing tools, which are then suitably employed in the optimum ship routing algorithm. This developed algorithm was investigated using the wave height information from GEOSAT altimeter records. Dijkstra’s path optimization scheme, which employs optimal control theory and dynamic programming technique, is used to obtain reliable optimum route in a given random sea-state.  相似文献   

适应南海开发与保护需求的船舶装备思考          下载免费PDF全文

张铮铮  石亚军 《海洋开发与管理》2016,33(2):43-47

三沙市设立以来,其建设与发展迎来了前所未有的新契机。由于其特殊的自然环境,船舶装备建设无疑是"建设三沙、发展三沙"的核心环节之一。文章对三沙市船舶装备的发展需求进行了分析,介绍了其发展现状,并给出其建设的体系图,旨为三沙市船舶装备建设提供参考。  相似文献