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.

scholarly journals An Optimization Study on the Hull Form and Stern Appendage for Improving Resistance Performance of a Coastal Fishing Vessel

2021 ◽  
Vol 11 (13) ◽  
pp. 6124
Author(s):  
Jin-Won Yu ◽  
Min-Kyung Lee ◽  
Yang-Ik Kim ◽  
Sung-Bu Suh ◽  
Inwon Lee
Keyword(s):  
Fuel Efficiency ◽  
Variation Method ◽  
Design Parameters ◽  
Fishing Vessel ◽  
Hull Form ◽  
Fishing Vessels ◽  
Optimization Study ◽  
Principal Dimension ◽  
The Republic ◽  
Hull Forms

In response to the increasing number of free trade agreements (FTA) and the Trans-Pacific Partnership (TTP), it is necessary to develop next-generation fishing vessels for the littoral sea of the Republic of Korea. The main objectives of such fishing vessels are to enhance the comfort of the crew and to improve fuel efficiency under the newly established principal dimension. This paper employs the hull form variation method to obtain a series of forebody hull forms of the 19 gross tonnage class of a coastal composite fishing vessel. Chine breadth modification has been used for hull form variations. The objective function is the minimum value of wavemaking resistance. A parametric study was conducted to observe the effects of design parameters on the objective functions, and hull-form optimization was performed. In addition to the hull-form optimization, the effect of the stern flap was investigated in terms of both resistance and operational performances.

The Design and Development of Modern Lifeboats

1993 ◽  
Vol 207 (1) ◽  
pp. 3-22 ◽  
Author(s):  
F D Hudson ◽  
I A Hicks ◽  
R M Cripps
Keyword(s):  
Construction Materials ◽  
Design Parameters ◽  
Impact Loads ◽  
Design And Development ◽  
Hull Form ◽  
Evaluation Procedures ◽  
History Of ◽  
Design Requirements ◽  
Operational Practices ◽  
Hull Forms

Well-established operational practices have determined the evolution of RNLI lifeboats throughout their history. The RNLI's requirement/or an all-fast offshore fleet of the self-righting type by 1993, however, motivated the need to re-examine basic design parameters of boats and launching equipment. More recent requirements to improve lifeboat performance further have demanded even closer evaluation of design requirements of hull form, machinery installation and construction materials. This paper outlines the history of the development of RNLI craft and describes the procedures for the design and development of its newest classes of lifeboat (FAB 3 and FAB 4), for which extensive model testing of differing hull forms was evaluated, various types of machinery were reviewed and construction, although in composite materials, was carefully designed to accommodate high hydrodynamic and impact loads. Technical trials and operational evaluation procedures are also discussed.

Statistical Design of Experiments Applied to the Design of Compliant Vertical Access Risers

2012 ◽  
Author(s):  
Michele A. L. Martins ◽  
Eduardo S. S. Silveira ◽  
Eduardo N. Lages
Keyword(s):  
Design Of Experiments ◽  
Optimization Design ◽  
Objective Measure ◽  
Statistical Design ◽  
Statistical Technique ◽  
Oil Field ◽  
Design Parameters ◽  
Structural Constraints ◽  
Statistical Design Of Experiments ◽  
Field Development

This paper applies design of experiments (DOE) methodology to the design of Compliant Vertical Access Risers (CVAR). This relatively new riser configuration is characterized by its differentiated geometry, achieved by the use of syntactic buoyancy at the lower section of the riser and additional weight at its upper section. The characteristic compliance of the CVAR system is obtained by providing an excessive length of pipe and a horizontal offset between the riser top and end connections. Thus, this system provides vertical access to dispersed subsea wells and its compliance can also compensate for vessel motion. CVAR, being vertical access to the wells, brings the advantage of using dry trees, and also allows the completion and workover operations to be performed from the FPU, offering significantly economic and operational benefits to deepwater oil field development. To guarantee such benefits, some operational and structural constraints must be satisfied. The design of the CVAR system is dependent upon several parameters. This study can provide a better understanding about the behavior of the CVAR in terms of its design parameters by the use of the DOE methodology. DOE is a statistical technique that provides an objective measure of how design parameters are correlated and the effective contribution of each at the riser performance. Consideration of the main effects as well as interaction effects coupled with sensitivity analysis is essential for insightful interpretation of model results and effective decision-making. Thus, this study contributes with the design of Compliant Vertical Access Risers as well as with a methodology that can lead to efficient riser design, being a first step in the optimization design process.

Multi-objective optimization of trimaran sidehull arrangement via surrogate-based approach for reducing resistance and improving the seakeeping performance

2020 ◽  
pp. 147509022098027
Author(s):  
Amin Nazemian ◽  
Parviz Ghadimi
Keyword(s):  
Drag Reduction ◽  
Hydrodynamic Performance ◽  
Navier Stokes ◽  
Computational Time ◽  
Vertical Position ◽  
Vertical Acceleration ◽  
Seakeeping Performance ◽  
Hull Design ◽  
Hull Forms ◽  
Heave Motion

Trimaran hull forms have been very attractive in the past decade. Hydrodynamic performance of trimaran ships is influenced by sidehull arrangement. The present study was intended to construct a surrogate model for better understanding of the hydrodynamic performance of a trimaran ship. Accordingly, seakeeping and resistance of an inverted-bow trimaran were considered as objectives of a simulation-based design (SBD) optimization framework. Different longitudinal, transversal, and vertical position of trimaran’s sidehull were investigated based on an advanced free-surface steady Reynolds-averaged Navier–Stokes (URANS) solver within StarCCM+ for resistance calculation and 3D panel method in Ansys-AQWA for seakeeping analyses. Quality and applicability of metamodeling optimization and its computational time were examined for future trimaran hull design projects. Total resistance for drag reduction, pitch and heave motion, and vertical acceleration at fore perpendicular for seakeeping performance were objectives of the study. The optimization results indicated a 6.9% drag reduction and 4.7% improvement in seakeeping performance, which yield lower longitudinal and large transversal distances of the sidehull. Furthermore, the conducted investigations demonstrated the effectiveness and capability of the proposed optimization platform for other marine industrial projects.

scholarly journals Mixed-Fidelity Design Optimization of Hull Form Using CFD and Potential Flow Solvers

2021 ◽  
Vol 9 (11) ◽  
pp. 1234
Author(s):  
Gregory J. Grigoropoulos ◽  
Christos Bakirtzoglou ◽  
George Papadakis ◽  
Dimitrios Ntouras
Keyword(s):  
Potential Flow ◽  
Stokes Equations ◽  
Computing Time ◽  
Navier Stokes ◽  
Design Parameters ◽  
Geometrical Parameters ◽  
Viscous Effects ◽  
Hull Form ◽  
Calm Water ◽  
Hull Forms

The present paper proposes a new mixed-fidelity method to optimize the shape of ships using genetic algorithms (GA) and potential flow codes to evaluate the hydrodynamics of variant hull forms, enhanced by a surrogate model based on an Artificial Neural Network (ANN) to account for viscous effects. The performance of the variant hull forms generated by the GA is evaluated for calm water resistance using potential flow methods which are quite fast when they run on modern computers. However, these methods do not take into account the viscous effects which are dominant in the stern region of the ship. Solvers of the Reynolds-Averaged Navier-Stokes Equations (RANS) should be used in this respect, which, however, are too time-consuming to be used for the evaluation of some hundreds of variants within the GA search. In this study, a RANS solver is used prior to the execution of the GA to train an ANN in modeling the effect of stern design geometrical parameters only. Potential flow results, accounting for the geometrical design parameters of the rest of the hull, are combined with the aforementioned trained meta-model for the final hull form evaluation. This work concentrates on the provision of a more reliable framework for the evaluation of hull form performance in calm water without a significant increase of the computing time.

scholarly journals Optimization of a Cyclone Using Multiphase Flow Computational Fluid Dynamics

2020 ◽  
Vol 142 (3) ◽  
Author(s):  
Justin Weber ◽  
William Fullmer ◽  
Aytekin Gel ◽  
Jordan Musser
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Multiphase Flow ◽  
Vortex Tube ◽  
Statistical Design ◽  
Optimization Method ◽  
Department Of Energy ◽  
Design Parameters ◽  
Statistical Design Of Experiments ◽  
Original Design

Abstract The U.S. Department of Energy National Energy Technology Laboratory's (NETL) 50 kWth chemical looping reactor (CLR) has an underperforming cyclone, which was designed using empirical correlations. To improve the performance of this cyclone using computational fluid dynamics (CFD)-based modeling simulations, four critical design parameters including the vortex tube radius and length, barrel radius, and the inlet width and height were optimized. NETL's open source multiphase flow with interphase exchange (MFiX) CFD code has been used to model a series of cyclones by systematically varying the geometric design parameters. To perform the optimization process, the surrogate modeling and sensitivity analysis followed by the optimization capability in nodeworks was used. The basic methodology for the process is to employ a statistical design of experiments (DOE) method to generate sampling simulations that fill the design space. Corresponding CFD models are then created, executed, and postprocessed. A response surface is created to characterize the relationship between input parameters and the quantities of interest (QoI). Finally, the CFD-surrogate is used by an optimization method to find the optimal design condition based on the objective and constraints prescribed. The resulting optimal cyclone has a larger diameter and longer vortex tube, a larger diameter barrel, and a taller and narrower solids inlet. The improved design has a predicted pressure drop 11 times lower than the original design while reducing the mass loss by a factor of 2.3.

scholarly journals Statistical Process Design for Hybrid Layered Manufacturing

2012 ◽  
pp. 253-259
Author(s):  
Mukesh Dubey ◽  
Arvind Ojha ◽  
Jitendra Verma ◽  
Sanjay Goyal ◽  
Ajay Bangar
Keyword(s):  
Design Procedure ◽  
Statistical Design ◽  
Weld Bead ◽  
Design Parameters ◽  
Welding Parameters ◽  
Bead Geometry ◽  
Statistical Design Of Experiments ◽  
Weld Bead Geometry ◽  
Statistical Process ◽  
Bead Width

The welding parameters such as current, voltage, arc length, wire feed rates, wire stick-out distance etc will influence on the deposited weld bead geometry. Statistical design of experiments using orthogonal arrays and signal-to-noise (S/N) ratios are performed to constitute the core of the robust design procedure. Taguchi Methodology was employed with minimum number of trails as compared with classical statistical experiments. This study systematically revels the complex cause-effect relationships between design parameters and performance. Thus an optimized weld bead width and heights are formulated for the exterior contour weld path deposition and for the interior layer metal path deposition respectively.

scholarly journals Recent developments in the design of fast ships

2011 ◽  
Vol 5 (9) ◽  
pp. 57
Author(s):  
J. L. Gelling ◽  
J. A. Keuning
Keyword(s):  
High Speed ◽  
Future Generation ◽  
Future Research ◽  
Hull Form ◽  
Concept Model ◽  
Seakeeping Performance ◽  
Recent Developments ◽  
Hull Design ◽  
Vertical Accelerations ◽  
Under Construction

During the last twenty years, Damen Shipyards, a multinational shipbuilding group with 6000 employees worldwide, has done extensive research on the development of hull designs for fast monohull vessels. In the 1990s the Enlarged Ship Concept was developed, leading to highly improved sea keeping capabilities and vessel behaviour in waves at high speed. This hull design concept was applied in the Damen SPa 4207 patrol vessel and has proven extremely successful, reducing vertical accelerations by 50% and, thus, allowing vessels to keep operating at high speed in waves. Over 25 units of the Damen SPa 4207 have been delivered so far. After the successful introduction of the Enlarged Ship Concept, Damen and Delft University continued developing the next generation hull form: the axebow design. Compared to the already good sea keeping capacities of the Enlarged Ship Concept, model tests indicated a further reduction of vertical accelerations. This was proven by real-time measurements on the first built axebow vessels in 2006 and 2007. In the last 3 years, over 30 axe bow supply vessels have been delivered to very satisfied operators. As a next step, Damen has applied the axe bow design to the latest patrol vessel design, the Damen SPa 5009. The first vessel of this design is currently under construction and its trials are scheduled by the end of 2011. The paper describes the background of the research done by Damen and Delft University, focusing on the mathematical and scientific aspects of the axebow design and its application on various ship types. The development and design of the latest Damen patrol vessel, SPa 5009, will be introduced, describing its seakeeping performance, operatability and crew ergonomics. Finally, the paper will mention the current and future research topics that Damen and Delft University are working on together, identifying the developments of the future generation patrol vessels.

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