Multicriterion Optimization of Stern Flap Design

2006 ◽  
Vol 43 (01) ◽  
pp. 42-54
Author(s):  
Michael G. Parsons ◽  
David J. Singer ◽  
Christopher M. Gaal
Keyword(s):  
Model Test ◽  
Cost Model ◽  
Specific Model ◽  
Design Parameters ◽  
Surface Model ◽  
Specific Response ◽  
Preliminary Design ◽  
Baseline Design ◽  
Multicriterion Optimization ◽  
Flap Design

Stern flaps have been used in many recent designs of transom stern vessels to provide increased top speed or to realize improvements in fuel economy over the operating range. The use of stern flaps has also become a practical retrofit on existing designs because significant improvements can be achieved at very minimal cost. Model test data from a limited series of stern flap designs for a group of combatant type vessels were utilized to develop a preliminary design model for stern flaps for these vessels. This model has been incorporated into Visual VB/Microsoft Excel-based software that will permit the investigation of the benefits of stern flaps in preliminary design. Within the limitations of the model, this software will also perform the multicriterion optimization needed to establish the initial parameters for a stern flap in preliminary design. This preliminary design can become the baseline design for use in a subsequent model test program. The software will then accept the results of tests of a systematic stern flap family developed about the baseline design and create a project-specific response surface model that can be used in subsequent detailed design. The software can then be utilized again to provide multicriterion optimization of this project-specific model to establish final design parameters for the stern flap.

An Approximate Method for Intact Stability of Fishing Vessels

1999 ◽  
Vol 36 (03) ◽  
pp. 171-174
Author(s):  
Hüseyin Yilmaz ◽  
Abdi Kükner
Keyword(s):  
Design Stage ◽  
Design Parameters ◽  
Preliminary Design ◽  
Ship Stability ◽  
Fishing Vessels ◽  
Initial Stability ◽  
Intact Stability ◽  
Preliminary Design Stage ◽  
Reduce Risk ◽  
Vessel Stability

It is well known that stability is the most important safety requirement for ships. One should have some information on ship stability at the preliminary design stage in order to reduce risk. Initial stability of ships is an important criterion and can be closely evaluated in terms of form parameters and vertical center of gravity. In this study, using some sample ship data, approximate formulations are derived by means of regression analysis for the calculations expressed in terms of ship preliminary design parameters that can easily provide approximate GM calculations. Thus designers can be provided with ship stability at the preliminary design stage, and also a set of appropriate design parameters for improving vessel stability can easily be determined.

Research on Diffusion Effect of Sewage Marine Discharge from Different Angles

2014 ◽  
Vol 675-677 ◽  
pp. 551-555
Author(s):  
Hang Yu
Keyword(s):  
Phase Ii ◽  
Marine Environment ◽  
Model Test ◽  
Deep Water ◽  
Large Angle ◽  
Premature Convergence ◽  
Design Parameters ◽  
Diffusion Effect ◽  
Environmental Material ◽  
Port Engineering

The sewage diffusion is an environmental material for protecting marine environment. It plays an important role in port engineering. Its effect under deep water was carried out between different diffuser design parameters based on the hydraulic model test, and YangKou port sewage marine disposal project phase II was taken as an example. For this project, jet angle was controlled to be 0 degree, and horizontal angle was controlled to be 0 degree. It not only can ensure that sewage fully diluted mixed, also can avoid the premature convergence and sewage lifting. It is feasible for selecting large angle nozzle under deep water and there are some technical bases have been provided for other sewage marine disposal project.

scholarly journals An Approximate Method for Calculation of Mean Statistical Value of Ship Service Speed on a Given Shipping Line , Useful in Preliminary Design Stage

2015 ◽  
Vol 22 (1) ◽  
pp. 28-35
Author(s):  
Katarzyna Żelazny
Keyword(s):  
Wind Waves ◽  
Parametric Method ◽  
Weather Conditions ◽  
Economic Effects ◽  
Design Stage ◽  
Design Parameters ◽  
Preliminary Design ◽  
Screw Propeller ◽  
Calm Water ◽  
Preliminary Design Stage

Abstract During ship design, its service speed is one of the crucial parameters which decide on future economic effects. As sufficiently exact calculation methods applicable to preliminary design stage are lacking the so called contract speed which a ship reaches in calm water is usually applied. In the paper [11] a parametric method for calculation of total ship resistance in actual weather conditions (wind, waves, sea current), was presented. This paper presents a parametric model of ship propulsion system (screw propeller - propulsion engine) as well as a calculation method, based on both models, of mean statistical value of ship service speed in seasonal weather conditions occurring on shipping lines. The method makes use of only basic design parameters and may be applied in preliminary design stage.

scholarly journals Approximation of the index for assessing ship sea-keeping performance on the basis of ship design parameters

2007 ◽  
Vol 14 (3) ◽  
pp. 21-26 ◽  
Author(s):  
Tomasz Cepowski
Keyword(s):  
Neural Networks ◽  
Artificial Neural Networks ◽  
Ship Design ◽  
Design Parameters ◽  
Preliminary Design ◽  
Operational Effectiveness ◽  
Design Problems ◽  
New Approach ◽  
Analytical Functions ◽  
Effectiveness Index

Approximation of the index for assessing ship sea-keeping performance on the basis of ship design parameters This paper presents a new approach which makes it possible to take into account seakeeping qualities of ship in the preliminary stage of its design. The presented concept is based on representing ship's behaviour in waves by means of the so called operational effectiveness index. Presented values of the index were calculated for a broad range of design parameters. On this basis were elaborated analytical functions which approximate the index depending on ship design parameters. Also, example approximations of the index calculated by using artificial neural networks, are attached. The presented approach may find application to ship preliminary design problems as well as in ship service stage to assess sea-keeping performance of a ship before its departure to sea.

An Approximate Method for Cross Curves of Cargo Vessels

2001 ◽  
Vol 38 (02) ◽  
pp. 92-94
Author(s):  
Huseyin Yilmaz ◽  
Mesut Giiner
Keyword(s):  
Prediction Method ◽  
Design Stage ◽  
Series Data ◽  
Design Parameters ◽  
Preliminary Design ◽  
Hull Form ◽  
Beam Depth ◽  
Preliminary Design Stage ◽  
The Mathematical Model ◽  
Load Conditions

In this study, a formula is presented to estimate cross curves of cargo vessels and to predict statical stability at the preliminary design stage of the vessel. The predictive technique is obtained by regression analysis of systematically varied cargo vessel series data. In order to achieve this procedure, some cargo vessel forms are generated using Series-60. The mathematical model in this predictive technique is constructed as a function of design parameters such as length, beam, depth, draft, and block coefficient. The prediction method developed in this work can also be used to determine the effect of specific hull form parameters and the load conditions on stability of cargo vessels. The present method is applied to a cargo vessel and then the results of the actual ship are compared with those of regression values.

Research of Sewage Marine Discharge Diffusion Effect under Deep Water

2013 ◽  
Vol 726-731 ◽  
pp. 1027-1031
Author(s):  
Hang Yu ◽  
Jing Feng Bai ◽  
Xin Hai Wang ◽  
Hong Xin Zhao
Keyword(s):  
Model Test ◽  
Deep Water ◽  
Near Field ◽  
Large Angle ◽  
Hydraulic Model ◽  
Experimental Results ◽  
Premature Convergence ◽  
Design Parameters ◽  
Diffusion Effect ◽  
Horizontal Angle

The sewage diffusion effect under deep water was carried out between different diffuser design parameters based on the hydraulic model test, and Huizhou Dayawan sewage marine disposal project was taken as an example. The experimental results show that the design parameters are significant for sewage diffusion at the near field. For Dayawan project, jet angle was controlled to be 20 degree, and horizontal angle was controlled to be 90 degree. It not only can ensure that sewage fully diluted mixed, also can avoid the premature convergence and sewage lifting. It is feasible for selecting large angle nozzle under deep water and there are some technical bases have been provided for other sewage marine disposal project.

Preliminary Design of Small-Scale Supercritical CO2 Radial Inflow Turbines

2020 ◽  
Vol 142 (2) ◽  
Author(s):  
Tina Unglaube ◽  
Hsiao-Wei D. Chiang
Keyword(s):  
Optimum Design ◽  
Supercritical Co2 ◽  
Velocity Ratio ◽  
Design Procedure ◽  
Expansion Ratio ◽  
Maximum Efficiency ◽  
Design Parameters ◽  
Small Scale ◽  
Preliminary Design ◽  
Line Design

Abstract In recent years, supercritical CO2 (sCO2) Brayton cycles have drawn the attention of researchers due to their high cycle efficiencies, compact turbomachinery, and environmental friendliness. For small-scale cycles, radial inflow turbines (RIT) are the prevailing choice and one of the key components. A mean line design procedure for sCO2 RIT is developed and design space exploration conducted for a 100 kW-class turbine for a low-temperature waste-heat utilization sCO2 Brayton cycle. By varying the two design parameters, specific speed and velocity ratio, different turbine configurations are setup and compared numerically by means of computational fluid dynamics (CFD) simulations. Results are analyzed to conclude on optimum design parameters with regard to turbine efficiency and expansion ratio. Specific speeds between 0.2 and 0.5 are recommended for sCO2 RIT with small though flow (3 kg/s). The higher the velocity ratio, the bigger the turbine expansion ratio. Pairs of optimum design parameters that effectuate maximum efficiency are identified, with smaller velocity ratios prevailing for smaller specific speeds. The turbine simulation results for sCO2 are compared to well-established recommendations for the design of RIT from literature, such as the Balje diagram. It is concluded that for the design of sCO2 RITs, the same principles can be used as for those for air turbines. By achieving total-to-static stage and rotor efficiencies of 84% and 86%, respectively, the developed mean line design procedure has proven to be an effective and easily applicable tool for the preliminary design of small-scale sCO2 RIT.

Application of Design Axioms to Marine Design Problems

2000 ◽  
Author(s):  
Y. S. Yang ◽  
B. S. Jang ◽  
Y. S. Song ◽  
Y. S. Yeon ◽  
S. H. Do
Keyword(s):  
Structural Design ◽  
Probabilistic Approach ◽  
Design Stage ◽  
Design Parameters ◽  
Independence Axiom ◽  
Preliminary Design ◽  
Functional Requirements ◽  
Mapping Procedure ◽  
Information Axiom ◽  
The Given

Abstract The Design Axioms proposed by N. P. Suh consist of Independence Axiom and Information Axiom. The Independence Axiom assists a designer in generating good design alternatives by considering the relations between the functions and the physical product using a hierarchical mapping procedure. The Information Axiom, which is related to the probability of achieving the given functional requirements, can be used as a criterion for the selection of the best solution among the proposed alternatives in the conceptual or preliminary design stage. In the early stages of marine design, especially ship design, there exists a lot of uncertainty because of the size and complexity of a marine vehicle. The uncertainty often leads to a probabilistic approach rather than a deterministic approach. The ship designs are mostly routine design to change an existing design case a little. In this paper, the availability of the Design Axioms in this marine design field will be investigated through three examples. In the conceptual design of a thruster, the Independence Axiom will be proven to be useful in examining the independence of functional requirements at each level of the decomposition process. In main engine selection example, the Information Axiom will be used for selecting the best solution among the given alternatives by estimating their respective information contents under the uncertain and ambiguous condition. In the structural design, some difficulties arise in maintaining the independence of functional requirements in general because the number of design parameters is greater than that of functional requirements. Therefore, there is much trouble in generalizing the application of the Design Axioms for the structural design, especially for the preliminary design where the principal design parameters of a design object have to be determined after its shape fixed. This paper will try a generalized approach to the similarity-based design where it is important to select which parameters should be changed and in what order they should be changed. How to make use of the Design Axioms will be showed in a barge design example. However, a lot of research is needed for the generalized application of the Design Axioms for the structural design.

Application of Math-Based Marketing and Financial Tools in an Automated Parametric Design Framework

2004 ◽  
Author(s):  
Joseph A. Donndelinger ◽  
Peter A. Fenyes
Keyword(s):  
Market Share ◽  
Parametric Design ◽  
Cost Model ◽  
Design Parameters ◽  
Parameter Study ◽  
Design Framework ◽  
Net Income ◽  
Cost Estimates ◽  
Technical Cost ◽  
S Model

A suite of math-based marketing and financial tools has been deployed and exercised within an automated, multidisciplinary parametric design framework. This suite of tools includes a market share estimator based on Cook’s S-Model, a Technical Cost Model for estimating the variable and fixed costs of the vehicle’s body system, a database of cost estimates for other vehicle systems, and a profit estimator developed from a standard accounting template. Development of the S-Model market share estimator included completion of a Demand-Price analysis for the midsize sedan segment and collection of publicly available value curves predominantly covering the powertrain performance and interior roominess disciplines. A flexible input-output interface was developed for the Technical Cost Model to provide a means of propagating changes in body design parameters throughout the framework. A series of exercises including analysis of a baseline vehicle, optimization of a hypothetical vehicle concept for net income, and a hypothetical architectural parameter study were conducted to demonstrate the capabilities of a multidisciplinary parametric design framework enabled with marketing and financial tools. These exercises demonstrate that existing engineering and business discipline tools can effectively interoperate to design for profitability in a multidisciplinary parametric design environment. They also illustrate several key challenges in automated design for profitability, such as those encountered in defining the role of price as a design variable in a tightly coupled design-for-profit system and in generating cost estimates using a continuously variable design representation.

Decision Matrix Reduction in Preliminary Design

2003 ◽  
Author(s):  
Amit Kaldate ◽  
Deborah Thurston ◽  
Hamidreza Emamipour ◽  
Mark Rood
Keyword(s):  
Pollution Control ◽  
Cost Minimization ◽  
Design Parameters ◽  
Large Set ◽  
Preliminary Design ◽  
Air Pollution Control ◽  
Decision Matrix ◽  
Matrix Methods ◽  
Decision Variables ◽  
Engineering Parameters

Matrix methods such as the house of quality (HOQ) are useful as a first step in organizing the information relating product attributes to engineering design parameters. However, they frequently result in a large number of elements, making it very difficult to focus attention on elements that bring maximum benefits. This paper presents a method for reducing a large set of engineering parameters to a more efficient subset. This subset offers the greatest potential for cost control, and is where product development, experimental, and optimization efforts should be focused. An example of a new air pollution control system illustrates the method. The most efficient set of engineering parameters are identified, and are then defined as decision variables in a cost minimization model. The optimal design identified by the method significantly reduces cost.

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