AN OPTIMIZATION MODEL FOR PRELIMINARY STABILITY AND CONFIGURATION ANALYSES OF SEMI-SUBMERSIBLES

2021 ◽  
Vol 159 (A3) ◽  
Author(s):  
G D Gosain ◽  
R Sharma ◽  
Tae-wan Kim
Keyword(s):  
Optimization Model ◽  
Design Method ◽  
Optimization Techniques ◽  
Design Approach ◽  
Preliminary Design ◽  
Design Environment ◽  
Preliminary Stage ◽  
Steel Weight ◽  
Motion Characteristics ◽  
Almost All

In the modern era of design governed by economics and efficiency, the preliminary design of a semi-submersible is critically important because in an evolutionary design environment new designs evolve from the basic preliminary designs and the basic dimensions and configurations affect almost all the parameters related to the economics and efficiency (e.g. hydrodynamic response, stability, deck load and structural steel weight of the structure, etc.). The present paper is focused on exploring an optimum design method that aims not only at optimum motion characteristics but also optimum stability, manufacturing and operational efficiency. Our proposed method determines the most preferable optimum principal dimensions of a semi-submersible that satisfies the desired requirements for motion performance and stability at the preliminary stage of design. Our proposed design approach interlinks the mathematical design model with the global optimization techniques and this paper presents the preliminary design approach, the mathematical model of optimization. Finally, a real world design example of a semi-submersible is presented to show the applicability and efficiency of the proposed design optimization model at the preliminary stage of design.

An Optimization Model for Preliminary Stability and Configuration Analyses of Semi-submersibles

2017 ◽  
Vol Vol 159 (A3) ◽  
Author(s):  
G D Gosain ◽  
R Sharma ◽  
Tae-wan Kim
Keyword(s):  
Optimization Model ◽  
Design Method ◽  
Optimization Techniques ◽  
Design Approach ◽  
Preliminary Design ◽  
Design Environment ◽  
Preliminary Stage ◽  
Steel Weight ◽  
Motion Characteristics ◽  
Almost All

In the modern era of design governed by economics and efficiency, the preliminary design of a semi-submersible is critically important because in an evolutionary design environment new designs evolve from the basic preliminary designs and the basic dimensions and configurations affect almost all the parameters related to the economics and efficiency (e.g. hydrodynamic response, stability, deck load and structural steel weight of the structure, etc.). The present paper is focused on exploring an optimum design method that aims not only at optimum motion characteristics but also optimum stability, manufacturing and operational efficiency. Our proposed method determines the most preferable optimum principal dimensions of a semi-submersible that satisfies the desired requirements for motion performance and stability at the preliminary stage of design. Our proposed design approach interlinks the mathematical design model with the global optimization techniques and this paper presents the preliminary design approach, the mathematical model of optimization. Finally, a real world design example of a semi-submersible is presented to show the applicability and efficiency of the proposed design optimization model at the preliminary stage of design.

A Design Approach for Storage Spar Buoy Platforms in the Concept and Preliminary Design Phases

2002 ◽  
Author(s):  
Richard David Schachter ◽  
Carlos Gomes Jordani ◽  
Antonio Carlos Fernandes
Keyword(s):  
Weight Control ◽  
Method Development ◽  
Design Method ◽  
Design Approach ◽  
Preliminary Design ◽  
Concept Design ◽  
Structural Topology ◽  
General Arrangement ◽  
Control Stability ◽  
Definition Of

The objective of this work is to present a design approach for the Concept and Preliminary Design Phases of Storage SPAR Buoy Platforms and to describe how the design method was developed. The influence of a VIV porosity device on the design is taken into consideration. The inherent advantages of Spar concepts for Petrobras’ applications for 1250 m, are discussed and compared with other concepts. The Spar concept was chosen. The design method development was carried out by means of a brainstorming process, using sketches and the creation of interactive flowcharts of the design processes (similar to a design spiral) comprising the main design factors, their sequencing and interrelations, for both the Concept and Preliminary Design phases. The intent of the design approach is to provide the designer with means to define quick and efficiently the optimal hull dimensions for a pre-established scenario. For the Concept Design, the method includes the definition of the main dimensions, the Wellbay, the structural topology and compartmentation, general arrangement, weight control, stability (intact, damaged and flooded), motions and mooring. A discussion on the influence of the VIV porosity device on the dimensioning and mooring of the Spar Platform is provided. A concept design application example is presented.

scholarly journals The GENUS aircraft conceptual design environment

2018 ◽  
Vol 233 (8) ◽  
pp. 2932-2947 ◽  
Author(s):  
H Smith ◽  
D Sziroczák ◽  
GE Abbe ◽  
P Okonkwo
Keyword(s):  
Practical Reasoning ◽  
Design Method ◽  
Aircraft Design ◽  
Theoretical Background ◽  
Optimization Techniques ◽  
Design Environment ◽  
Modern Computer ◽  
Computer Based ◽  
Design Software ◽  
Aircraft Conceptual Design

The design of aircraft has evolved over time from the classical design approach to the more modern computer-based design method utilizing multivariate design optimization. In recent years, aircraft concepts and configurations have become more diverse and complex thus pushing many synthesis packages beyond their capability. Furthermore, many examples of aircraft design software focus on the analysis of one particular concept thus requiring separate packages for each concept. This can lead to complications in comparing concepts and configurations as differences in performance may originate from different prediction toolsets being used. This paper presents the GENUS Aircraft Design Framework developed by Cranfield University’s Aircraft Design Group to address these issues. The paper reviews available aircraft design methodologies and describes the challenges faced in their development and application. Following this, the GENUS aircraft design environment is introduced, along with the theoretical background and practical reasoning behind the program architecture. Particular attention is given to the programming, choice of methodology, and optimization techniques involved. Subsequently, some applications of the developed methodology, implemented in the framework are presented to illustrate the diversity of the approach. Three special classes of aircraft design concept are presented briefly.

Preliminary Design of Centrifugal Impellers Using Optimization Techniques

1994 ◽  
Vol 116 (2) ◽  
pp. 310-315 ◽  
Author(s):  
Sarim AL-Zubaidy
Keyword(s):  
Numerical Optimization ◽  
Relative Velocity ◽  
Design Method ◽  
Optimization Techniques ◽  
Preliminary Design ◽  
Minimum Entropy ◽  
Calculation Point ◽  
The Mean ◽  
Minimum Entropy Generation ◽  
General Configuration

The paper proposes a design method which may be used to evaluate the detailed geometry of an impeller (handling compressible and perfect fluid) from a prescribed mean streamline velocity distribution. The analysis makes use of numerical optimization, firstly in the step by step channel geometry calculation, and secondly in controlling the manner in which the relative velocity components are permitted to vary along the mean streamline for the condition of minimum entropy generation along the flow path. The components distribution of the relative velocity were not allowed to take arbitrary values, the variation of the radial, axial and tangential components was governed in such a way that the prescribed diffusion schedule is satisfied at every calculation point. The general configuration of the example design shows it to be well proportional and should not be difficult to manufacture.

Design and Optimization of Missile Three-Loop Autopilot Based on Performance Indicators

2012 ◽  
Vol 203 ◽  
pp. 36-40
Author(s):  
Lin Dong Zhao ◽  
Sheng Jing Tang
Keyword(s):  
Genetic Algorithm ◽  
Frequency Domain ◽  
Performance Indicators ◽  
Optimization Model ◽  
System Performance ◽  
Optimization Design ◽  
Design Method ◽  
Good Effect ◽  
Preliminary Design ◽  
Design And Optimization

A classic design method in frequency domain was used in preliminary design of three-loop autopilot. The preliminary design results derived out the bounds and initial values of optimization variables. Based on the system performance indicators, an optimization model was proposed including the use of weight factors and typical values of performance indicators. The optimization design was realized and verified with the use of genetic algorithm (GA) built in Matlab Optimization Toolbox. The design instance shows that the optimization model and strategy have a good effect and could meet the optimization needs when different performance focuses are desired.

scholarly journals Research on Blank Optimization Design Based on Low-Carbon and Low-Cost Blank Process Route Optimization Model

2021 ◽  
Vol 13 (4) ◽  
pp. 1929
Author(s):  
Yongmao Xiao ◽  
Wei Yan ◽  
Ruping Wang ◽  
Zhigang Jiang ◽  
Ying Liu
Keyword(s):  
Optimization Model ◽  
Optimization Design ◽  
Design Method ◽  
Low Cost ◽  
Route Optimization ◽  
Low Carbon ◽  
Multi Objective Optimization ◽  
Multi Objective ◽  
Blank Design ◽  
Process Route

The optimization of blank design is the key to the implementation of a green innovation strategy. The process of blank design determines more than 80% of resource consumption and environmental emissions during the blank processing. Unfortunately, the traditional blank design method based on function and quality is not suitable for today’s sustainable development concept. In order to solve this problem, a research method of blank design optimization based on a low-carbon and low-cost process route optimization is proposed. Aiming at the processing characteristics of complex box type blank parts, the concept of the workstep element is proposed to represent the characteristics of machining parts, a low-carbon and low-cost multi-objective optimization model is established, and relevant constraints are set up. In addition, an intelligent generation algorithm of a working step chain is proposed, and combined with a particle swarm optimization algorithm to solve the optimization model. Finally, the feasibility and practicability of the method are verified by taking the processing of the blank of an emulsion box as an example. The data comparison shows that the comprehensive performance of the low-carbon and low-cost multi-objective optimization is the best, which meets the requirements of low-carbon processing, low-cost, and sustainable production.

Impact of Secondary Flow on the Accuracy of Simplified Design Methods for Steam Turbine Stages

2012 ◽  
Author(s):  
Jan Schumann ◽  
Ulrich Harbecke ◽  
Daniel Sahnen ◽  
Thomas Polklas ◽  
Peter Jeschke ◽  
...  
Keyword(s):  
Secondary Flow ◽  
Steam Turbine ◽  
Design Process ◽  
Design Method ◽  
Computing Time ◽  
Leading Edge ◽  
Design Methods ◽  
Preliminary Design ◽  
Line Design ◽  
Radial Equilibrium

The subject of the presented paper is the validation of a design method for HP and IP steam turbine stages. Common design processes have been operating with simplified design methods in order to quickly obtain feasible stage designs. Therefore, inaccuracies due to assumptions in the underlying methods have to be accepted. The focus of this work is to quantify the inaccuracy of a simplified design method compared to 3D Computational Fluid Dynamics (CFD) simulations. Short computing time is very convenient in preliminary design; therefore, common design methods work with a large degree of simplification. The origin of the presented analysis is a mean line design process, dealing with repeating stage conditions. Two features of the preliminary design are the stage efficiency, based on loss correlations, and the mechanical strength, obtained by using the beam theory. Due to these simplifications, only a few input parameters are necessary to define the primal stage geometry and hence, the optimal design can easily be found. In addition, by using an implemented law to take the radial equilibrium into account, the appropriate twist of the blading can be defined. However, in comparison to the real radial distribution of flow angles, this method implies inaccuracies, especially in regions of secondary flow. In these regions, twisted blades, developed by using the simplified radial equilibrium, will be exposed to a three-dimensional flow, which is not considered in the design process. The analyzed design cases show that discrepancies at the hub and shroud section do exist, but have minor effects. Even the shroud section, with its thinner leading-edge, is not vulnerable to these unanticipated flow angles.

POVERTY REDUCTION, UNEMPLOYMENT AND RURAL DEVELOPMENT; AFTERMATH OF COVID-19 PANDEMIC IN NIGERIA

2021 ◽  
Vol 9 (1) ◽  
pp. 36-49
Author(s):  
Oderinu Hassana ◽  
◽  
Kadir Mumini ◽  
Tijani Adebayo ◽  
Keyword(s):  
Economic Development ◽  
Rural Development ◽  
Rural Areas ◽  
Poverty Reduction ◽  
Design Method ◽  
Gear Up ◽  
Global Pandemic ◽  
High Level ◽  
Almost All ◽  
Self Administered Questionnaire

Nigeria has one of the countries whose experience of poverty and unemployment is on the high side makes this study to look into the effect of the economic lockdown during the global pandemic in the country, with the aim of making effort on how this effect can be translated into economic development. Survey research design method was adopted with self-administered questionnaire used to collect data. Findings revealed that in Nigeria COVID -19 outbreak effects was felt in almost all sectors and the aftermath greatly affected the country’s GDP and this adversely affect rural development in the country, which translated to a worrisome rate of poverty and unemployment. Hence, both individual and government have now seen that campaigning for economic diversification is not sufficient for economic development but rather a prompt swing into action by all is needed for sustainable development of rural areas to respond to the worrisome rate of unemployment and in turn high level of poverty caused by the COVID-19 lockdown in the country. It was recommended that government at all level as well as individuals and stakeholders should put in place actions that would gear up rural development and set policies at their various helms of affairs that would encourage economic participation of all citizens in all sector of the economy.

Eat Smart! Ontario's Healthy Restaurant Program: A Survey of Participating Restaurant Operators

2003 ◽  
Vol 64 (4) ◽  
pp. 202-207 ◽  
Author(s):  
Lesley A. Macaskill ◽  
John J.M. Dwyer ◽  
Connie L. Uetrecht ◽  
Carol Dombrow
Keyword(s):  
Public Health ◽  
Program Implementation ◽  
Design Method ◽  
Mail Survey ◽  
Health Promotion Program ◽  
First Year ◽  
Communication Education ◽  
Family Style ◽  
Quick Service ◽  
Almost All

Eat Smart! Ontario's Healthy Restaurant Program is a standard provincial health promotion program. Public health units grant an award of excellence to restaurants that meet designated standards in nutrition, food safety, and non-smoking seating. The purpose of this study was to assess whether program objectives for participating restaurant operators were achieved during the first year of program implementation, and to obtain operators’ recommendations for improving the program. Dillman's tailored design method was used to design a mail survey and implement it among participating operators (n = 434). The design method, which consisted of four mail-outs, yielded a 74% response rate. Fifty percent of respondents operated family-style or quick-service restaurants, and 82% of respondents learned about the program from public health inspectors. Almost all respondents (98%) participated in the program mainly to have their establishments known as clean and healthy restaurants, 65% received and used either point-of-purchase table stands or postcards to promote the program, and 98% planned to continue participating. The respondents’ suggestions for improving the program were related to the award ceremony and program materials, media promotion, communication, education, and program standards. Program staff can use the findings to enhance the program.

scholarly journals HOTEL RESORT DI TELAGA SARANGAN

Arsitektura ◽  
2017 ◽  
Vol 14 (1) ◽  
Author(s):  
Dewi Saraswati ◽  
Ahmad Farkhan ◽  
Amin Sumadyo
Keyword(s):  
Architectural Design ◽  
Negative Impact ◽  
Design Method ◽  
Building Design ◽  
Problem Formulation ◽  
Design Concept ◽  
Preliminary Design ◽  
Literature Study ◽  
Initial Idea ◽  
Resort Hotel

<em>The design of Sarangan Lake resort done by the needs of tourist on its area, unfullfield of tourist needs on accommodation facilities, increasing number of uncare building towards negative impact to the environment, so the purpose from this design is to get a building design that could provide accommodation facilities to the tourist of Sarangan Lake, with the design that concern about environment. The design issue is how ecological architect can be applied into design of Sarangan Lake resort. Design method is using architectural design, started from initial idea, preliminary understanding of architecture about the planned object, research and problem formulation, literature study as substantial reference, data analysis and information, analysis of general and specific approach towards designed object and formulation of design concept, analysis of design concept approach which more specific about the to-be-designed object, and architectural design transformation and preliminary design as well. The result is a design concept of resort hotel facilities as lodging accommodations by applying the characteristic of the ecological architect to the building design.</em>

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