View non-flash version
www.sname.org/sname/mt January 2013 demonstrate that the IQSD is more eective and exible than previous ship domains, and the intelligent SCR based on the GIQSD is rea- sonable and dependable. Near-Field Hydrodynamics of a Surface-Eect Ship BY LAWRENCE J. DOCTORS PUBLISHED IN THE SEPTEMBER JOURNAL OF SHIP RESEARCHA consistent near-eld linearized potential- ow analysis of a surface-eect ship traveling at a steady speed in laterally restricted water of nite depth is described. Additionally, the inuence of seals, in terms of their drag and lift on the vessel, is included in the theory. e predicted results include the sinkage and trim, the resistance components, and the pro- le of the free surface of the water along the sidehulls. ese predictions are compared with the corresponding results measured on a towing tank model. It is demonstrated that the inclusion of the inuence of the seals sub- stantially improves the numerical predictions for the sinkage and trim. Good agreement is achieved for the total resistance provided a frictional form factor of 1.306 is used. e cor- relation between theory and experiment for the prole of the free surface is high, except in the vicinity close to the bow, where the non- linear eects in that region are strong. Prediction of Plate Bending by Multi Divisional Analysis in Induction Heating BY YOUNG HWA LEE PUBLISHED IN THE SEPTEMBER JOURNAL OF SHIP RESEARCHInduction heating is more ecient for plate bending because of its easy operation and control of working parameters compared with heating by a torch. In this study, a more ecient method was proposed for the pre- diction of plate bending. e conventional analysis method using the axis symmet- ric coil model could not handle the varying temperature during the heating and form- ing process for curved plates with a convex, a concave, or a twisted curvature. e pro- posed method using some discrete divisions and steps in this study could overcome these diculties and show more accurate, reason -able results of temperatures and deections in at or curved plates. is method is com- posed of multidisciplinary analyses such as an electro-magnetic analysis, a heat transfer analysis, and a deformation analysis based on inherent strain method and elastic defor- mation analysis. Validation of Potential-Flow Estimation of Interaction Forces Acting upon Ship Hulls in Parallel Motion BY SERGE SUTULO, C. GUEDES SOARES, AND JANNE F. OTZEN PUBLISHED IN THE SEPTEMBER JOURNAL OF SHIP RESEARCHThe hydrodynamic interaction problem is of great importance for numerical ship handling simulators. At present, only a rel- atively simple potential double-body panel method can be expected to supply esti- mates of interaction forces and moments in real time on commonly used hardware, without limitations on the hull shape, and on the mutual position and motion of the interacting bodies. Such a code was devel- oped on the basis of the classic Hess and Smith method and proved to be fast enough to model interaction in real time when a moderate number of panels is used. In the present paper, results obtained with the potential code are validated against experimental data obtained in deep- and shallow-water towing tanks for the case of a tug operating near a larger vessel. All the tests corresponded to the steady regime and only cases with parallel center planes were considered here. The comparisons carried out for various discretization of the hulls provide useful information about natural limitations in breaking at too close lateral distances and about acceptable trade-o between the computational speed and accuracy. In addition, inuence of the nonzero sway and yaw velocities is investi- gated numerically. Addressing Complexity Aspects in Conceptual Ship Design: A Systems Engineering Approach BY HENRIQUE M. GASPAR, DONNA H. RHODES, ADAM M. ROSS, AND STEIN OVE ERIKSTAD PUBLISHED IN THE NOVEMBER JOURNAL OF SHIP PRODUCTION AND DESIGN This article approaches the complexity aspects of conceptual ship design from a sys- tems engineering point of view. We introduce the issue by dening the term complexity in systems engineering, placing the conceptual ship design task as a complex system problem and creating analogies between generic com- plex systems and a ship. Five main aspects of complexity are presented, linking challenges of the conceptual phase to each of the aspects. e structural aspect is related to the arrange- ment and interrelationship of the physical objects in the ship. The behavioral aspect derives from the form-function mapping. e external circumstances to which the ship is subjected are approached through the con- textual aspect. Uncertainties in the scenarios and changes over time are related to the tem- poral aspect. e perceptual aspect relates to how stakeholders perceive the value that they receive from a chosen design. A theo- retical study to address these ve aspects is presented, applying the responsive systems comparison method in the conceptual design of an anchor handling a tug supply vessel. e last section discusses why decomposing the complexities of the ship design task in ve aspects is a benet. MTGO DEEPER Both the Journal of Ship Production and Design and the Journal of Ship Research are available by subscription. Go to www.sname.org/SNAME/Pubs/Journals1/ and ?nd out why these technical journals are indispensable to naval architects and marine engineers around the world.