Optimization of Wigley hull form in order to ensure the objective functions of the seakeeping performance

2014 ◽  
Vol 13 (4) ◽  
pp. 422-429 ◽  
Author(s):  
Hassan Bagheri ◽  
Hassan Ghassemi
Keyword(s):  
Objective Functions ◽  
Hull Form ◽  
Seakeeping Performance ◽  
Wigley Hull

scholarly journals A new mathematical hull-form with 10-shape parameters for evaluation of ship response in waves

2021 ◽  
Author(s):  
Sadaoki Matsui
Keyword(s):  
Sensitivity Analysis ◽  
Wave Loads ◽  
Shape Parameters ◽  
Hull Form ◽  
Second Moment ◽  
Explicit Function ◽  
Seakeeping Performance ◽  
Wigley Hull ◽  
Simple Evaluation ◽  
Anterior Posterior

AbstractThis study presents a new mathematical hull-form that is expressed as an explicit function with 10 hull-form parameters, which is called the Matsui hull-form in this study. The proposed hull-form was developed by expanding the modified Wigley hull-form so that the following 10 hull-form parameters can be independently varied: main dimensions $$L$$ L , $$B$$ B , $$d$$ d , fineness coefficients $${C}_{b}$$ C b , $${C}_{\mathrm{m}}$$ C m , $${C}_{\mathrm{w}}$$ C w , second moment of waterplane area coefficient $${C}_{\mathrm{w}2}$$ C w 2 , longitudinal center of buoyancy LCB and floatation LCF, and a parameter $$\beta$$ β related to anterior–posterior asymmetry. The main purpose of this hull-form is that it is utilized for the following two objects: the first is the simple evaluation of the seakeeping performance and wave loads in the early ship designing stage without any detailed offset data, and the second is a systematical study on the influence of a ship’s dimensions on the ship response in waves. This paper presents the derivation of the Matsui hull-form and the applicability of the proposed hull-from was confirmed by comparing the ship response in waves with the actual ships. Moreover, a sensitivity analysis of the ship response in waves was conducted as an example of the application of the proposed hull-form.

Some Guidance for Hull Form Selection for SWATH Ships

1988 ◽  
Vol 25 (04) ◽  
pp. 239-252
Author(s):  
G. Robed Lamb
Keyword(s):  
High Speed ◽  
Early Stage ◽  
The United States ◽  
Practical Application ◽  
Hull Form ◽  
Stage Design ◽  
Seakeeping Performance ◽  
The World ◽  
Selection For ◽  
Early Stage Design

Even though in 1987 there were only a dozen SWATH (smali-waterplane-area twin-hull) craft and ships afloat around the world, word of their markedly superior seakeeping performance is spreading rapidly. The number of SWATH vessels is likely to double within five years. As in many other areas of technology, the United States and Japan are the acknowledged leaders in the development and practical application of the SWATH concept. This paper reviews the characteristics of existing SWATH craft and ships from the standpoint of the stated seakeeping objective. Hull form differences between four SWATH craft and ships, including the Navy's SSP Kairnalino, are analyzed and interpreted. Important considerations for the early-stage design of a SWATH ship are discussed. Differences in the range of feasible hull form geometries for coastal areas and unrestricted ocean operations, and for low-speed versus moderately high-speed applications, are pointed out.

A Seakeeping Study of the UBC Series

1997 ◽  
Vol 34 (01) ◽  
pp. 10-23
Author(s):  
Sander M. Calisal ◽  
David Howard ◽  
Jon Mikkelsen
Keyword(s):  
British Columbia ◽  
Measurement Procedure ◽  
Collection System ◽  
Fishing Vessel ◽  
The West ◽  
Hull Form ◽  
University Of British Columbia ◽  
Fishing Vessels ◽  
Seakeeping Performance ◽  
The University

The University of British Columbia (UBC) and the British Columbia Research Incorporated (BCRI) collaborated to design a fishing vessel suitable for use on the west coast of Canada. This vessel, called the UBC Series parent hull form, was designed to have a large aft deck area and a volumetric coefficient comparable to those of modern Canadian fishing vessels. The resistance characteristics of this hull were improved without compromising on functionality and usable space. A resistance algorithm developed from the results for a systematic series of low-L/B displacement-type vessels, the UBC Series, was previously published (Calisal&McGreer, 1993). However, during the design process, the seakeeping performance of the vessel was never addressed. This paper describes the seakeeping performance of the UBC series in head seas. An algorithm, developed from the results of the model tests, can be used to calculate the seakeeping response of similar low L/B vessels. To calibrate the seakeeping measurement procedure, tank instrumentation, and data collection system, the ITTC Standard Seakeeping hull form (the S-175 hull form) was tested and the results were compared against published results for this hull form. The same techniques used for the standard hull form were then used to measure the seakeeping performance of the UBC Series. Possible application of the algorithm for non-UBC Series forms is also discussed.

scholarly journals Effects of Hull Form Variations on Resistance and Seakeeping Performance of Planing Hulls with and without Incoming Regular Waves

2014 ◽  
Vol 51 (5) ◽  
pp. 369-379 ◽  
Author(s):  
Dong Jin Kim ◽  
Sun Young Kim ◽  
Seong Hwan Kim ◽  
Jeong Hwa Seo ◽  
Shin Hyung Rhee
Keyword(s):  
Regular Waves ◽  
Hull Form ◽  
Seakeeping Performance

Seakeeping Analysis of a High-Speed Monohull With a Motion-Control Bow Hydrofoil

2004 ◽  
Vol 48 (02) ◽  
pp. 77-117 ◽  
Author(s):  
Paul D. Sclavounos ◽  
Henning Borgen
Keyword(s):  
Motion Control ◽  
High Speed ◽  
Three Dimensional ◽  
Control Device ◽  
Control Mechanisms ◽  
Hull Form ◽  
Active Motion ◽  
Seakeeping Performance ◽  
Seakeeping Analysis ◽  
Longitudinal Position

The seakeeping performance is studied of a foil-assisted high-speed monohull vessel using a state-of-the-art three-dimensional Rankine panel method. The vessel is equipped with a bow hydrofoil acting as a passive heave and pitch motion-control device in waves. The formulation of the seakeeping of ships equipped with lifting appendages is developed, and the mechanisms responsible for the reduction of the heave and pitch motions of high- speed vessels equipped with hydrofoils are studied. The sensitivity of the heave and pitch motions on the longitudinal position of the hydrofoil is studied. It is found that the most efficient location for the hydrofoil is at the ship bow leading to a 50% reduction of the root mean square values of the heave and pitch motions in a Joint North Sea Wave Project (JONSWAP) spectrum. Several extensions of the analysis of the present paper are discussed. They include the reduction of the roll motion of high-speed vessels, the design of optimal active motion-control mechanisms, and the coupling of the hull form and lifting appendage design for high-speed monohull vessels.

Potential of Michell’s Integral for Ship Wave Resistance

2014 ◽  
Author(s):  
Takashi Tsubogo
Keyword(s):  
Integral Equation ◽  
Froude Number ◽  
Computing Time ◽  
Wave Resistance ◽  
Boundary Integral ◽  
Hull Form ◽  
Number Range ◽  
Gradient Effect ◽  
Depth Direction ◽  
Wigley Hull

The Michell’s integral (Michell 1898) for the wave making resistance of a thin ship has not been used widely in practice, since its accuracy is questioned especially for a Froude number range about 0.2 to 0.35 for conventional ships. We examine calculations by Michell’s integral for some ship forms, e.g. a parabolic strut, Wigley hull and so on. As a result, one reason of the disagreement with experiments is revealed. It must be the gradient of hull form in the depth direction. Then a thin ship theory including the hull gradient effect in the depth direction is presented, which improves slightly in low Froude numbers but needs more computing time than Michell’s integral so as to solve a boundary integral equation.

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

2013 ◽  
Vol 10 (1) ◽  
pp. 1-12 ◽  
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

Analysis of Variance to Determine the Effect of Hull Form Parameters on Resistance and Seakeeping Performance for PSV Hulls

2016 ◽  
Author(s):  
Nicholas Boyd ◽  
David Molyneux
Keyword(s):  
Analysis Of Variance ◽  
Statistical Design ◽  
Design Parameters ◽  
Statistical Design Of Experiments ◽  
Hull Form ◽  
Seakeeping Performance ◽  
Head Waves ◽  
Hull Design ◽  
Hull Forms ◽  
The Relationship

Throughout the world many Platform Supply Vessel designs have been proposed as the optimal form for their given operating environment, but evaluating these claims has been difficult due to a poor understanding of the relationships between hull form shapes and performance for these vessels. This paper presents the results of analysis aimed at determining these relationships. Results of CFD calculations to determine the Effective Horsepower/tonne for a series of PSV designs were presented in the paper A step towards an optimum PSV Hull form. This paper presents results for 16 separate hull forms, which were designed as each possible combination of four two-level hull form parameters. The hull form features considered were bow shape (vertical stem or bulbous), flat of bottom (flat or deadrise), length of parallel mid body (short or long), and stern shape (convention or integrated); resistance was calculated at two typical operating speeds (10 and 14 knots). This set of results was favourable for analysis using the statistical design of experiments technique: analysis of variance, which was used to determine the relationship between the hull and resistance performance. The same hull form series was used to study the effects of the hull form parameters on motions in head waves. A 2 level factorial experiment was designed based on the hull parameters with the heave and pitch response calculated using the potential flow ship motion prediction code Shipmo3D, for each of two representative wave conditions (summer light seas and winter heavy seas) at the zero speed and 10 knot operating speed. Analysis of variance was used to analyze the heave and pitch responses measured, and was used to determine the relationship between each hull parameter and each response. In both cases a 5% F-test was used to determine the significance of each parameter studied, and the significant effects were analyzed to determine their contributions to the overall model of the data. The results have found the relationships between the hull design parameters and the Effective Horespower/tonne, heave, and pitch response of the vessel, indicating which factors provide the largest contribution to minimizing each response. The interaction effects between factors were also examined to allow for a generalized understanding of the resulting effect of selecting one hull parameter over another. A numerical model combining all significant factors was fitted to the data, allowing for multiple objective optimization to determine which hull forms provide the most desirable performance for each response.

Hull Form Optimization of a TriSWACH for Reduced Drag

2015 ◽  
Author(s):  
Fuxin Huang ◽  
Lijue Wang ◽  
Chi Yang ◽  
Richard A. Royce
Keyword(s):  
Drag Reduction ◽  
Surrogate Model ◽  
Objective Functions ◽  
Hull Form ◽  
Multi Objective ◽  
Speed Range ◽  
Hydrodynamic Optimization

A new methodology for hydrodynamic optimization of a TriSWACH is developed, which considers the shape of the center hull only and its optimal results are not influenced by the position configuration of side hulls. In order to accelerate the process of the optimization, a practical multi-objective hydrodynamic tool has been further developed by integrating a surrogate model to approximate the objective functions and constraints. The proposed method and the further developed tool are applied to optimize the hull form of a TriSWACH with nine possible side hull position configurations for reduced drag. A considerable drag reduction is obtained by the optimal TriSWACH for various side hull configurations and speed range.

Three-Dimensional Forward-Speed Seakeeping Calculation Using FINE/Marine

2016 ◽  
Author(s):  
Limin Chen ◽  
Guanghua He ◽  
Dazheng Wang ◽  
Zihao Zhang
Keyword(s):  
Numerical Model ◽  
Three Dimensional ◽  
Navier Stokes ◽  
Forward Speed ◽  
Ship Waves ◽  
Continuity Equations ◽  
Seakeeping Performance ◽  
Calm Water ◽  
Wigley Hull ◽  
Unsteady Problems

A time-domain seakeeping numerical model based on a computational fluid dynamics (CFD) software FINE/Marine has been developed for nonlinear steady and unsteady viscous flows. Simulation of multi-phase flows around a Wigley hull with forward speed is performed by solving the Reynolds-average Navier-Stokes (RANS) and continuity equations with k-ω (SST-Menter) turbulence model. The water free surface is captured by Blend Reconstruction Interface Capturing Scheme (BRICS). Both steady and unsteady problems including wave-making, radiation and diffraction problems are simulated. Ship waves generated by the Wigley model advancing at a constant forward speed in calm water or incident waves are computed. The numerical results including the wave-making resistance and wave patterns for steady problem, hydrodynamic coefficients and forces for unsteady problems are illustrated and compared with experimental measurements in good agreement. It is confirmed that the present numerical model has the capability of evaluating the seakeeping performance of ships.

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