ALBERT

Description:    Cost is perhaps the most influential factor in the outcome of a product or service within many of today’s industries. Cost assessment during the early stage of ship design is crucial. It influences the go, no-go decision concerning a new development. Cost assessment occurs at various stages of ship design development. Economic evaluation as early as possible, in the design phase, is therefore vital to find the best pricefunction compromise for the ship projects. The authors have developed a feature-based costing model for cost effectiveness measurements intended to be used by ship designers for the real time control of cost process. The outcome is that corrective actions can be taken by management in a rather short time to actually improve or overcome predicted unfavourable performance. Content Type Journal Article Category Original article Pages 1-15 DOI 10.1007/s00773-012-0163-4 Authors J.-D. Caprace, ANAST, University of Liège, 1 Chemin des chevreuils, 4000 Liège, Belgium P. Rigo, ANAST, University of Liège, 1 Chemin des chevreuils, 4000 Liège, Belgium Journal Journal of Marine Science and Technology Online ISSN 1437-8213 Print ISSN 0948-4280

Description:    In the present study a novel modeling approach is presented to solve the combined internal sloshing and sea-keeping problem. The model deals with interesting effects arising due to the coupled interaction between the sloshing in partially filled containers of several geometries and the ship motion. The study is very important for the liquid cargo carrier operating in rough sea or under different environmental conditions. The resulting slosh characteristics that include transient pressure variation, free surface profiles and hydrodynamic pressure over the container walls have been reported in this study. In addition, the effects of coupled ship response and sloshing on ship motion parameters have also been investigated. The equations of motion of fluid, considered inviscid, irrotational, and partially compressible, are expressed in terms of the pressure variable alone. A finite difference-based iterative time-stepping technique is employed to advance the coupled solution in the time domain. Several parameters of interest, including the container parameters, level of liquid, thrusters modeling and some important environmental factors are investigated. Content Type Journal Article Category Original article Pages 1-15 DOI 10.1007/s00773-012-0157-2 Authors S. Mitra, Department of Mechanical Engineering, National University of Singapore, 1 Engineering Drive 2, Singapore, 117576 Singapore L. V. Hai, Department of Civil Engineering, Ho Chi Minh City University of Technology, 268 Ly Thuong Kiet Street, District 10, Ho Chi Minh City, Vietnam L. Jing, Institute of High Performance Computing, A STAR, Singapore, Singapore B. C. Khoo, Department of Mechanical Engineering, National University of Singapore, 1 Engineering Drive 2, Singapore, 117576 Singapore Journal Journal of Marine Science and Technology Online ISSN 1437-8213 Print ISSN 0948-4280

Description:    Hydrodynamic optimizations of ship hull forms have been carried out employing parametric curves generated by fairness-optimized B-Spline form parameter curves, labeled as F-Spline. Two functionalities of the parametric geometry models are used in the present study: a constrained transformation function to account for hull form variations and a geometric entity used in full parametric hull form design. The present F-Spline based optimization procedure is applied to two distinct hydrodynamic hull form optimizations: the global shape optimization of an ultra-large container ship and the forebody hull form for the hydrodynamic optimization of an LPG carrier. Improvements of ship performance achieved by the proposed F-Spline procedure are demonstrated through numerical experiments and through correlations with experimental data. The ultra-large containership was built and delivered to the ship owner. The present study validates the effectiveness of the proposed hydrodynamic optimization procedure, ushering in process automation and performance improvement in practical ship design practices. Content Type Journal Article Category Review Article Pages 1-17 DOI 10.1007/s00773-011-0148-8 Authors Soonhung Han, Department of Ocean System Engineering, KAIST, 291 Daehak-ro, Yuseong-gu, Daejeon, 305-701 Republic of Korea Yeon-Seung Lee, Department of Ocean System Engineering, KAIST, 291 Daehak-ro, Yuseong-gu, Daejeon, 305-701 Republic of Korea Young Bok Choi, Hydrodynamics R&D Group, Ship and Ocean R&D Institute, Daewoo Shipbuilding and Marine Engineering Co., Ltd. (DSME), 85, Da-dong, Jung-gu, Seoul, 100-180 Republic of Korea Journal Journal of Marine Science and Technology Online ISSN 1437-8213 Print ISSN 0948-4280

Description:    The Caspian Sea has a unique ecosystem that consists of endemic species. The deterioration of the unique ecosystem has become increasingly worrisome since a wide variety of pollutants have been released into the water. Water circulation plays a key role in advection and diffusion of these pollutants. In the present study, water circulation and thermohaline structures in the Caspian Sea were analyzed by means of a three dimensional numerical simulation. The effects of meteorological changes, river inflow, and an icing event were taken into account as boundary conditions. Numerical simulation was carried out for 20 years to achieve stable seasonal variations in model variables. As a result, the horizontal distributions of water temperature and salinity could be reproduced; the gradient of water temperature in the north–south direction, the decrease in water temperature along the east coast of the middle Caspian Sea due to coastal upwelling, and low salinity in the northern Caspian Sea. The icing event kept the water temperature in the northern Caspian Sea from decreasing to an unrealistic value. The observed cyclonic gyres were basically formed by the density-driven current due to thermohaline structure. Content Type Journal Article Category Original article Pages 1-13 DOI 10.1007/s00773-012-0159-0 Authors Daisuke Kitazawa, Underwater Technology Research Center, Institute of Industrial Science, The University of Tokyo, De-207, 4-6-1 Komaba, Meguro-ku, Tokyo, 153-8505 Japan Jing Yang, Graduate School of Engineering, The University of Tokyo, Tokyo, Japan Journal Journal of Marine Science and Technology Online ISSN 1437-8213 Print ISSN 0948-4280

Description:    A dissipative free-surface approach is applied to the potential flow problem with respect to a hydrofoil in a two-dimensional uniform stream. A dissipative source-based panel method is developed for a NACA foil problem with its trailing edge being a stagnation point, and also for a symmetric Joukowski foil problem with its trailing edge being a non-stagnation point. To facilitate the understanding of the further application of the dissipative free-surface approach, an underwater mathematical body model is presented. Numerical simulation with respect to the body in a three-dimensional uniform stream is provided from an analytic formulation obtained by the dissipative free-surface technique. Content Type Journal Article Category Original article Pages 1-10 DOI 10.1007/s00773-012-0199-5 Authors Zhi-Min Chen, Ship Science, University of Southampton, Southampton, SO17 1BJ UK Journal Journal of Marine Science and Technology Online ISSN 1437-8213 Print ISSN 0948-4280

Description:    Unsteady Reynolds averaged Navier–Stokes (URANS) computations of standard maneuvers are performed for a surface combatant at model and full scale. The computations are performed using CFDShip-Iowa v4, a free surface solver designed for 6DOF motions in free and semi-captive problems. Overset grids and a hierarchy of bodies allow the deflection of the rudders while the ship undergoes 6DOF motions. Two types of maneuvers are simulated: steady turn and zigzag. Simulations of steady turn at 35° rudder deflection and zigzag 20/20 maneuvers for Fr  = 0.25 and 0.41 using constant RPM propulsion are benchmarked against experimental time histories of yaw, yaw rate and roll, and trajectories, and also compared against available integral variables. Differences between CFD and experiments are mostly within 10 % for both maneuvers, highly satisfactory given the degree of complexity of these computations. Simulations are performed also with waves, and with propulsion at either constant RPM or torque. 20/20 zigzag maneuvers are simulated at model and full scale for Fr  = 0.41. The full scale case produces a thinner boundary layer profile compared to the model scale with different reaction times and handling needed for maneuvering. Results indicate that URANS computations of maneuvers are feasible, though issues regarding adequate modeling of propellers remain to be solved. Content Type Journal Article Category Original article Pages 1-16 DOI 10.1007/s00773-012-0196-8 Authors Pablo M. Carrica, IIHR Hydroscience and Engineering, The University of Iowa, Iowa City, IA 52242, USA Farzad Ismail, School of Aerospace Engineering, Universiti Sains Malaysia, 14300 Penang, Malaysia Mark Hyman, Naval Surface Warfare Center Panama City, Panama City, FL 32407-7001, USA Shanti Bhushan, Center for Advanced Vehicular Systems, Mississippi State University, Starkville, MS 39762, USA Frederick Stern, IIHR Hydroscience and Engineering, The University of Iowa, Iowa City, IA 52242, USA Journal Journal of Marine Science and Technology Online ISSN 1437-8213 Print ISSN 0948-4280

Description:    The inception of porpoising is theoretically predicted for planing vessels. Two different approaches are presented. First, a linear stability analysis is applied to find the porpoising limits while the hydrodynamic coefficients, i.e. added mass and damping coefficients, are determined by either a simplified method or a numerical method. Another approach is to seek the porpoising limits by performing nonlinear time domain simulations. Either the simplified method or the numerical method is used in the simulations. In the numerical method, a 2D+t theory together with a boundary element method is employed. The trim angle limits for porpoising are determined by changing the longitudinal position of the centre of gravity (COG) of the vessel and keeping the forward speed constant. The predicted porpoising limits are compared with Day and Haag’s (Planing boat porpoising, Thesis, Webb Institute of Naval Architecture, 1952 ) experimental results. The influences of parameters such as the load coefficient, the vertical position of COG and the radius of gyration of the ship are investigated by varying those parameters in the linear stability analysis. In the nonlinear time-domain simulations, by trying different longitudinal position of COG, one can find the critical trim angle when the porpoising commences. The obtained trim limits agree generally with those predicted by the linear stability analysis. Bounded oscillations for the unstable cases near the critical trim angle can be seen in the time-domain simulations due to the nonlinear effects. Content Type Journal Article Category Original Article Pages 270-282 DOI 10.1007/s00773-011-0125-2 Authors Hui Sun, Centre for Ships and Ocean Structures, Department of Marine Technology, Norwegian University of Science and Technology, 7491 Trondheim, Norway Odd M. Faltinsen, Centre for Ships and Ocean Structures, Department of Marine Technology, Norwegian University of Science and Technology, 7491 Trondheim, Norway Journal Journal of Marine Science and Technology Online ISSN 1437-8213 Print ISSN 0948-4280 Journal Volume Volume 16 Journal Issue Volume 16, Number 3

Description:    This paper details the CFD validation studies carried out as a prerequisite for multi-fidelity CFD-based design optimization of high-speed passenger-only ferries aimed at reducing far-field wake energy that causes beach erosion. A potential flow program (WARP) and a URANS program (CFDSHIP) were validated using full-scale measurements of resistance, sinkage, trim, and far-field wake train obtained over a wide range of speeds for two high-speed semi-planing foil-assisted catamarans: Spirit (LOA-22 m) and 1060 (LOA-17 m). This study posed a unique combination of challenges for CFD modeling: the foil appended geometry required complicated surface overset grids, the effect of the waterjet and wind resistance had to be modeled, and a method had to be devised to extrapolate the calculated near-field elevation to get the far-field wake train using Havelock sources. A more concentrated effort was applied to the URANS verification and validation which forms the focus of this paper. The results show that URANS is able to accurately predict the resistance and motions for both vessels when coupled with models that account for the propulsors and air resistance. The overall accuracy of URANS for the performance analysis of the foil-assisted, semi-planing catamarans was adequate to warrant its use as a tool for subsequent design and optimization of a new vessel with significantly reduced wakes. Content Type Journal Article Category Original Article Pages 157-167 DOI 10.1007/s00773-011-0120-7 Authors Manivannan Kandasamy, University of Iowa, Iowa City, IA, USA Seng Keat Ooi, University of Iowa, Iowa City, IA, USA Pablo Carrica, University of Iowa, Iowa City, IA, USA Frederick Stern, University of Iowa, Iowa City, IA, USA Emilio F. Campana, INSEAN, Rome, Italy Daniele Peri, INSEAN, Rome, Italy Philip Osborne, Golder Associates Inc., 18300 NE Union Hill Road, Suite 200, Redmond, WA 98052, USA Jessica Cote, Golder Associates Inc., 18300 NE Union Hill Road, Suite 200, Redmond, WA 98052, USA Neil Macdonald, Coldwater Consulting, Gloucester, ON, Canada Nic de Waal, Technicraft Ltd., Birkenhead, Auckland, New Zealand Journal Journal of Marine Science and Technology Online ISSN 1437-8213 Print ISSN 0948-4280 Journal Volume Volume 16 Journal Issue Volume 16, Number 2

Description:    We investigated the difference in fatigue behaviour between the aluminium alloys A5083-O and A5083-H321, which are used as structural components in ships and high speed craft. We obtained S–N curves for the base materials and the welded joints made of A5083-O. The relationships between the fatigue crack propagation rates and the stress intensity factor ranges Δ K , Δ K eff and Δ K RPG (Toyosada et al. in Int J Fatigue 26(9):983–992, 2004 ) were determined. Additionally, the evolution of fatigue crack growth for the base materials and the welded joints made of A5083-O was measured. We also carried out numerical simulations of fatigue crack growth for both base metals and their welded joints made of A5083-O. The difference in fatigue crack growth behaviour for each alloy and the validity of the numerical simulations of fatigue crack growth based on the RPG stress criterion (Toyosada et al. 2004 ) in the base materials and their welded joints was investigated. Content Type Journal Article Category Original Article Pages 343-353 DOI 10.1007/s00773-011-0124-3 Authors Koji Gotoh, Department of Marine Systems Engineering, Faculty of Engineering, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka, 819-0395 Japan Koji Murakami, Department of Civil and Structural Engineering, Graduate School of Engineering, Kyushu University, Fukuoka, Japan Yasuo Noda, Department of Civil and Structural Engineering, Graduate School of Engineering, Kyushu University, Fukuoka, Japan Journal Journal of Marine Science and Technology Online ISSN 1437-8213 Print ISSN 0948-4280 Journal Volume Volume 16 Journal Issue Volume 16, Number 3

Description:    In recent years there have been reports of serious accidents of parametric rolling for modern container ships and car carriers. For avoiding such accidents, a prediction method of parametric rolling in irregular seas is required. Since parametric rolling is practically non-ergodic, repetitions of numerical simulations or experiments could be not feasible to ascertain the behaviour. Therefore, in this paper, a method combining a stochastic approach with a deterministic approach in order to estimate the probabilistic index without such simple repetitions is developed. The ship's response in regular seas is estimated by solving an averaged system of the original 1-DoF roll model, and random waves necessary for occurrence of parametric rolling is achieved by using Longuet-Higgins’s or Kimura’s wave group theory. As a result, a fast and robust computation method of the probabilistic index is established. Finally, it is concluded that the proposed method is considered to be one of the useful tools for discussing the new IMO Intact Stability Code. Content Type Journal Article Category Original Article Pages 294-310 DOI 10.1007/s00773-011-0133-2 Authors Atsuo Maki, Graduate School of Maritime Sciences, Kobe University, 5-1-1 Fukae-Minami, Higashinada, Kobe, 658-0022 Japan Naoya Umeda, Department of Naval Architecture and Ocean Engineering, Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0971, Japan Shigeaki Shiotani, Graduate School of Maritime Sciences, Kobe University, 5-1-1 Fukae-Minami, Higashinada, Kobe, 658-0022 Japan Eiichi Kobayashi, Graduate School of Maritime Sciences, Kobe University, 5-1-1 Fukae-Minami, Higashinada, Kobe, 658-0022 Japan Journal Journal of Marine Science and Technology Online ISSN 1437-8213 Print ISSN 0948-4280 Journal Volume Volume 16 Journal Issue Volume 16, Number 3