The Effect of Hull Form Parameters on the Hydrodynamic Performance of a Bulk Carrier

In this study, the effect of joint optimization of the principal dimensions and hull form on the hydrodynamic performance of a bulk carrier was studied. In the first part of the joint optimization process, fast principal-dimension optimization of the origin parent ship considering the integrated performance of ship resistance, seakeeping, and maneuverability, as well as their relationships with the principal dimensions were analyzed in detail based on the ship resistance, seakeeping qualities, and maneuverability empirical methods of Holtrop and Mennen, Bales, and K and T indices, respectively. A new parent ship was chosen from 496 sets of hulls after comprehensive consideration. In the remaining part, a further hull form optimization was performed on the new parent ship according to the minimum wave-making resistance. The obtained results demonstrate that: (a) For the case in which the principal dimension of the original parent-type ship is different from that of the owner’s target ship, within the bounds of the relevant constraints from the owner, an excellent parent ship can be obtained by principal-dimension optimization; (b) the joint optimization method considering the principal dimension and hull form optimization can further explore the optimization space and provide a better hull.

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An evolutionary optimization technique applied to resistance reduction of the ship hull form

Journal of Naval Architecture and Marine Engineering ◽

10.3329/jname.v10i1.12927 ◽

2013 ◽

Vol 10 (1) ◽

pp. 1-12 ◽

Cited By ~ 1

Author(s):

Hassan Zakerdoost ◽

Hassan Ghassemi ◽

Mahmoud Ghiasi

Keyword(s):

Optimization Technique ◽

Ship Hull ◽

Point Of View ◽

Computational Method ◽

Hydrodynamic Performance ◽

Optimization Process ◽

Design Constraint ◽

Hull Form ◽

Performance Point ◽

Wigley Hull

Hull form optimization from a hydrodynamic performance point of view is an important aspect of ship design. This paper presents a computational method to estimate the ship resistance (viscous & wave) in calm-water. In the optimization process the evolution strategy (ES) technique is linked to the computational method to obtain an optimum hull form by taking into account the displacement as design constraint. For allowing the large variation of hull form during optimization process the hull surface is represented by NURBS. New hull forms are obtained from the well-known S60 hull and the classical Wigley hull taken as initial hulls in the optimization process at Fn=0.316. The optimization variables are a combination of ship hull offsets and main dimensions. The benchmark results for two test cases indicate that the total resistance of optimized hulls is reduced significantly.DOI: http://dx.doi.org/10.3329/jname.v10i1.12927

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Hull form optimization in the conceptual design stage considering operational efficiency in waves

Proceedings of the Institution of Mechanical Engineers Part M Journal of Engineering for the Maritime Environment ◽

10.1177/1475090218781115 ◽

2018 ◽

Vol 233 (3) ◽

pp. 745-759 ◽

Cited By ~ 2

Author(s):

Yoo-Won Jung ◽

Yonghwan Kim

Keyword(s):

Optimization Method ◽

Operational Efficiency ◽

Hydrodynamic Performance ◽

Design Stage ◽

Total Resistance ◽

Added Resistance ◽

Slender Body Theory ◽

Hull Form ◽

Weather Factor ◽

Calm Water

This study focuses on the optimization of ship dimensions by considering hydrodynamic performance in waves. In actual seaways, a ship experiences speed loss due to environmental loads by waves and wind. Therefore, along with calm water resistance, speed loss in waves should be considered in the hull form design in order to improve operational efficiency in waves. However, a trade-off may be needed between total resistance on the ship and the speed loss in waves. To address this problem, Non-dominated Sorting Genetic Algorithm II, which is a multi-objective optimization method, is used to minimize the total resistance on a ship in seaways and the speed loss by additional resistance. In the optimization process, added resistance is predicted using a numerical method based on slender-body theory, Maruo’s far-field formulation, and an empirical formula for added resistance in short waves. The speed loss in waves, which can be expressed by a weather factor ( fw), is estimated using power–speed curves. This article introduces some examples of the sensitivity analysis of added resistance and speed loss in waves to the variations of ship dimensions. Finally, the optimization solutions on a Pareto front set are compared to a basis ship in terms of hull form, and the corresponding hydrodynamic performances are evaluated.

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A Novel Joint Optimization Method Based on Mobile Data Collection for Wireless Rechargeable Sensor Networks

IEEE Transactions on Green Communications and Networking ◽

10.1109/tgcn.2021.3080918 ◽

2021 ◽

pp. 1-1

Author(s):

Azzedine Boukerche ◽

Qiyue Wu ◽

Peng Sun

Keyword(s):

Sensor Networks ◽

Data Collection ◽

Optimization Method ◽

Joint Optimization ◽

Mobile Data ◽

Mobile Data Collection ◽

Wireless Rechargeable Sensor Networks

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Shape-design optimization of hull structures considering thermal deformation

Proceedings of the Institution of Mechanical Engineers Part C Journal of Mechanical Engineering Science ◽

10.1177/0954406213517489 ◽

2013 ◽

Vol 228 (13) ◽

pp. 2266-2277

Author(s):

Myung-Jin Choi ◽

Min-Geun Kim ◽

Seonho Cho

Keyword(s):

Optimal Design ◽

Design Optimization ◽

Thermal Deformation ◽

Parametric Design ◽

Optimization Method ◽

Optimization Process ◽

Design Parameters ◽

Shape Design ◽

Shape Design Optimization ◽

Modified Method

We developed a shape-design optimization method for the thermo-elastoplasticity problems that are applicable to the welding or thermal deformation of hull structures. The point is to determine the shape-design parameters such that the deformed shape after welding fits very well to a desired design. The geometric parameters of curved surfaces are selected as the design parameters. The shell finite elements, forward finite difference sensitivity, modified method of feasible direction algorithm and a programming language ANSYS Parametric Design Language in the established code ANSYS are employed in the shape optimization. The objective function is the weighted summation of differences between the deformed and the target geometries. The proposed method is effective even though new design variables are added to the design space during the optimization process since the multiple steps of design optimization are used during the whole optimization process. To obtain the better optimal design, the weights are determined for the next design optimization, based on the previous optimal results. Numerical examples demonstrate that the localized severe deviations from the target design are effectively prevented in the optimal design.

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Simulation-Based Hybrid Optimization Method for the Digital Twin of Garment Production Lines

Journal of Computing and Information Science in Engineering ◽

10.1115/1.4050245 ◽

2021 ◽

Vol 21 (3) ◽

Author(s):

Woo-Kyun Jung ◽

Young-Chul Park ◽

Jae-Won Lee ◽

Eun Suk Suh

Keyword(s):

Expert Knowledge ◽

Structural Characteristics ◽

Optimization Method ◽

Hybrid Optimization ◽

Optimization Process ◽

Production Lines ◽

Distribution Method ◽

Workload Analysis ◽

Hybrid Optimization Method ◽

Simulation Based

AbstractImplementing digital transformation in the garment industry is very difficult, owing to its labor-intensive structural characteristics. Further, the productivity of a garment production system is considerably influenced by a combination of processes and operators. This study proposes a simulation-based hybrid optimization method to maximize the productivity of a garment production line. The simulation reflects the actual site characteristics, i.e., process and operator level indices, and the optimization process reflects constraints based on expert knowledge. The optimization process derives an optimal operator sequence through a genetic algorithm (GA) and sequentially removes bottlenecks through workload analysis based on the results. The proposed simulation optimization (SO) method improved productivity by ∼67.4%, which is 52.3% higher than that obtained by the existing meta-heuristic algorithm. The correlation between workload and production was verified by analyzing the workload change trends. This study holds significance because it presents a new simulation-based optimization model that further applies the workload distribution method by eliminating bottlenecks and digitizing garment production lines.

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A Novel Joint Optimization Method for Adaptive Hand-held Video Stabilization Based on Spatial-temporal Consistency

Proceedings of the 2019 International Conference on Modeling, Simulation, Optimization and Numerical Techniques (SMONT 2019) ◽

10.2991/smont-19.2019.26 ◽

2019 ◽

Author(s):

Xiao Li ◽

Shuai Li ◽

Hong Qin ◽

Aimin Hao

Keyword(s):

Optimization Method ◽

Joint Optimization ◽

Video Stabilization ◽

Temporal Consistency

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Sample Selection Method for Ship Resistance Performance Optimization Based on Approximated Model

Journal of Ship Research ◽

10.5957/jsr.2016.60.1.1 ◽

2016 ◽

Vol 60 (01) ◽

pp. 1-13

Author(s):

Haichao Chang ◽

Xide Cheng ◽

Zuyuan Liu ◽

Baiwei Feng ◽

Chengsheng Zhan

Keyword(s):

Performance Optimization ◽

Model Building ◽

Interpolation Method ◽

Uniform Design ◽

Sample Selection ◽

Selection Method ◽

Ocean Engineering ◽

Hull Form ◽

Ship Resistance ◽

Resistance Performance

Approximated model instead of computational fluid dynamics tool is utilized for performance analysis in hull form optimization process, which can save time significantly. Sample selection is the central issue of approximated model building. This article focuses on the sample selection method and the application of approximated model in hull form optimization. Latin hypercube sampling and uniform design are compared. The uniform design based on genetic algorithm approach is proposed. The radial basis function interpolation method is used for hull surface automatic modification. An approximated model using a neural network for ship resistance performance is established. The stem profile's optimization for the Korea Research Institute of Ships and Ocean Engineering (KRISO) container ship is completed. The results show that hull form optimization based on the approximated model can significantly improve optimization efficiency and is practical for engineering design.

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Hydrodynamic Optimization of a Wedge Hull

10.5957/fast-2015-020 ◽

2015 ◽

Author(s):

Lijue Wang ◽

Fuxin Huang ◽

Chi Yang ◽

Raju Datla

Keyword(s):

Hydrodynamic Performance ◽

Surface Mesh ◽

Nurbs Surface ◽

Bottom Edge ◽

Hull Form ◽

Entrance Angle ◽

Total Drag ◽

Rounded Corner ◽

Bulbous Bow ◽

Hydrodynamic Optimization

A novel wedge-shaped hull form is optimized for reduced drag using a further developed practical hydrodynamic optimization tool. The hull features a sharp entrance angle, rectilinear sides, sharp bottom edges, a triangular waterplane and a linear aftward taper from a deep bow to a shallow transom. The optimization involves two modifications of the hull form, one is to smooth out the sharp bottom edge with a rounded corner and the other is to generate a bulbous bow. In order to perform the hydrodynamic optimization of the hull, a Non-Uniform Rational BSpline (NURBS)-based hull surface modification tool, a NURBS surface mesh generator, a surrogate model and an evolutionary optimization solver are developed and integrated into the practical hydrodynamic optimization tool. The hydrodynamic performances, i.e., the total drag and the flow field near the obtained hull bodies are assessed and compared with the original wedge hull using numerical simulations. Results showed that rounding the sharp edge of the wedge hull can reduce the total drag by alleviating the flow separations around the hull body. The wedge hull with rounded bottom edge and optimized bulbous bow can achieve larger drag reduction and the flow separations are almost eliminated. The total drag of the optimal hull is compared with an earlier-optimized wedge hull that has a different type of bulbous bow, whose hydrodynamic performance has been validated by model tests.

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