The Experts below are selected from a list of 31377 Experts worldwide ranked by ideXlab platform
Pothuganti Ramesh - One of the best experts on this subject based on the ideXlab platform.
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controlling the block coefficient of Ship hull stability to optimize the Ship hull Design using fluid dynamic analysis
International Journal of Research, 2020Co-Authors: Pothuganti RameshAbstract:Ship hull is water tight body which plays a major role in Ship’s effective transport system. Ship hull structure Design has recently become more and more important topic. Whole structure of Ship hull to be considered, technically and economically. It is a very important part in Ship management industry because total strength of Ship Design and cost, 20% is only for making Ship hull structure Design. Output of Ship’s main engine is increased with less vibration in rigid propeller along with accurate hull structure Design. Ship hull structure Design accurate when hull consist of optimized block coefficient. So here need to control the block coefficient of Ship hull is considered as very important one. Previously more topics published on vibration controlling on propeller shafts and developing the Design of surface of Ship hull. Among the all works, this work is mainly researched on controlling the block coefficient (Not less, Not more) using different shapes of Ship hull.
Nickolas Vlahopoulos - One of the best experts on this subject based on the ideXlab platform.
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An integrated multidisciplinary particle swarm optimization approach to conceptual Ship Design
Structural and Multidisciplinary Optimization, 2010Co-Authors: Christopher G. Hart, Nickolas VlahopoulosAbstract:A particle swarm optimization (PSO) solver is developed based on theoretical information available from the literature. The implementation is validated by utilizing the PSO optimizer as a driver for a single discipline optimization and for a multicriterion optimization and comparing the results to a commercially available gradient based optimization algorithm, previously published results, and a simple sequential Monte Carlo model. A typical conceptual Ship Design statement from the literature is employed for developing the single discipline and the multicriterion benchmark optimization statements. In the main new effort presented in this paper, an approach is developed for integrating the PSO algorithm as a driver at both the top and the discipline levels of a multidisciplinary Design optimization (MDO) framework which is based on the Target Cascading (TC) method. The integrated MDO/PSO algorithm is employed for analyzing a multidiscipline optimization statement reflecting the conceptual Ship Design problem from the literature. Results are compared to MDO analyses performed when a gradient based optimizer comprised the optimization driver at all levels. The results, the strengths, and the weaknesses of the integrated MDO/PSO algorithm are discussed as related to conceptual Ship Design.
Apostolos Papanikolaou - One of the best experts on this subject based on the ideXlab platform.
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parametric multi objective optimisation of Ship s bow for the added resistance in waves
Ship Technology Research, 2016Co-Authors: V Bolbot, Apostolos PapanikolaouAbstract:For large Ships, the likely sea states the Ships that may encounter in their lifecycle are in the region of short length waves, compared to Ships' length, where the diffraction component of the added resistance (AR) is predominant. In this paper, a multi-objective optimisation of the bow form of the standard ITTC KVLCC2 tanker was performed in terms of the AR, calm water resistance, total resistance and energy efficiency Design index. The AR was estimated using semi-empirical formulas developed by the Ship Design Laboratory of NTUA. A parametric geometry model of Ship's bow region and optimisation process were developed by use of the CAESES/FriendShip-Framework. The conducted multi-objective optimisation procedure showed that the AR is strongly correlated to Ship's waterplane area coefficient, moderately to Ship's stem profile and weakly to the bow's flare angle. The optimised bow Design resembles closely the LEADGE-bow hull concept, which is becoming very popular in recent full type Ship new-buildings.
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Ship Design methodologies of preliminary Design
2014Co-Authors: Apostolos PapanikolaouAbstract:1 General on Ship Design 2 Selection of Main Dimensions and Calculation of Basic Ship Design Values 3 Ship's Hull Form 4 Naval Architectural Drawings and Plans 5 Machinery Installation, Propulsion and Steering Devices 6 Estimation of Building Cost Appendix A: Diagrams of Regression Analysis of Basic Design Values for Merchant Ships Appendix B: Systematic Hull Form - Model Series Appendix C: Determination of Ship's Displacement with the Relational Method of Normand Appendix D: Historical Evolution of Shipbuilding Appendix E: Subdivision and Damage Stability of Ships - Historical Developments and the Way Ahead
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stochastic uncertainty modelling for Ship Design loads and operational guidance
Ocean Engineering, 2014Co-Authors: Apostolos Papanikolaou, Alfred E Mohammed, Spyros HirdarisAbstract:Understanding and quantification of uncertainties are important attributes for the assessment of the performance, reliability and risk of complex engineering structures and systems. From a naval architecture perspective the consideration of the uncertainties related to Ship’s seakeeping responses and wave induced loads is necessary for the assessment of Ship Design as well as for safe and efficient Ship operations. To this end, the efficient processing of large amounts of data and the stochastic load combination by use of available numerical models may assist with the rationalisation of modelling assumptions and support the validation and verification of Design and decision making criteria in the context of risk based Ship Design. This paper presents recent advances in (a) modelling the combined hydrodynamic responses of Ship structures using cross-spectral combination methods and (b) in implementing uncertainty models used for the development of modern decision support systems as guidance to Ship’s master.
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safedor the implementation of risk based Ship Design and approval
Procedia - Social and Behavioral Sciences, 2012Co-Authors: Christian Breinholt, Dracos Vassalos, Apostolos Papanikolaou, Karlchristian Ehrke, Pierre C Sames, Rolf Skjong, Tom Strang, Thomas WitollaAbstract:The integrated project SAFEDOR has been completed in spring 2009 and this paper summarizes the achievements. SAFEDOR has been focusing work on the development of a risk-based regulatory framework, a risk-based Design framework, advanced probabilistic simulation tools and their integration as well as a series of application examples. The paper outlines the elements of the risk-based regulatory framework incl. approval process, risk evaluation criteria, requirements for documentation and key personnel as well as onboard documentation. Novel risk-based simulation tools and their integration into a Design environment are discussed. The paper also highlights the innovative Ship Designs developed within SAFEDOR and points towards possible future applications. Eventually, future research on risk-based approaches is outlined.
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holistic Ship Design optimization
Computer-aided Design, 2010Co-Authors: Apostolos PapanikolaouAbstract:Ship Design is a complex endeavor requiring the successful coordination of many disciplines, of both technical and non-technical nature, and of individual experts to arrive at valuable Design solutions. Inherently coupled with the Design process is Design optimization, namely the selection of the best solution out of many feasible ones on the basis of a criterion, or rather a set of criteria. A systemic approach to Ship Design may consider the Ship as a complex system integrating a variety of subsystems and their components, for example, subsystems for cargo storage and handling, energy/power generation and Ship propulsion, accommodation of crew/passengers and Ship navigation. Independently, considering that Ship Design should actually address the whole Ship's life-cycle, it may be split into various stages that are traditionally composed of the concept/preliminary Design, the contractual and detailed Design, the Ship construction/fabrication process, Ship operation for an economic life and scrapping/recycling. It is evident that an optimal Ship is the outcome of a holistic optimization of the entire, above-defined Ship system over her whole life-cycle. But even the simplest component of the above-defined optimization problem, namely the first phase (conceptual/preliminary Design), is complex enough to require to be simplified (reduced) in practice. Inherent to Ship Design optimization are also the conflicting requirements resulting from the Design constraints and optimization criteria (merit or objective functions), reflecting the interests of the various Ship Design stake holders. The present paper provides a brief introduction to the holistic approach to Ship Design optimization, defines the generic Ship Design optimization problem and demonstrates its solution by use of advanced optimization techniques for the computer-aided generation, exploration and selection of optimal Designs. It discusses proposed methods on the basis of some typical Ship Design optimization problems with multiple objectives, leading to improved and partly innovative Designs with increased cargo carrying capacity, increased safety and survivability, reduced required powering and improved environmental protection. The application of the proposed methods to the integrated Ship system for life-cycle optimization problem remains a challenging but straightforward task for the years to come.
Chryssostomos Chryssostomidis - One of the best experts on this subject based on the ideXlab platform.
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adding simulation capability to early stage Ship Design
Electric Ship Technologies Symposium, 2015Co-Authors: Matthew Ferrante, Chryssostomos Chryssostomidis, Julie Chalfa, Lake Langland, R A DougalAbstract:The Navy's early-stage Ship Design tools do not currently include an inherent simulation capability. Under Navy direction, the Electric Ship Research and Development Consortium (ESRDC) has worked to develop a simulation tool that can be used to determine functionality of Ship systems at the early stages of Design. This paper describes the current capabilities of the simulation tool and the process and status of the efforts to integrate this tool with the Navy's Design tools.
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a collaborative early stage Ship Design environment
2012Co-Authors: Julie Chalfa, Chryssostomos Chryssostomidis, Lake Langland, Sherif Abdelwahed, R A Dougal, Abhishek Dubey, El T Mezyani, J D Herbs, T Kiehne, J C OrdonezAbstract:Recent advances in sensor and weapons systems are significantly increasing the electrical power that is required and the thermal loads that must be dissipated onboard US Navy Ships. Thus, Design tools and methods must bring detailed consideration of all disciplines early in the Design process, including electrical, thermal and controls in addition to the traditional naval architecture and marine engineering. Effective interface of the multiple disciplines demands a collaborative Design process. The Electric Ship Research and Development Consortium (ESRDC) has developed the backbone structure of a collaborative Design environment with the goal of bringing together many disciplines early in the Ship Design process. This Design environment brings many innovations, especially in the arena of simultaneous collaborative Design. This paper describes the Smart Ship System Design (S3D) environment as developed to date, along with overall and discipline-specific visions of implementation of the environment in Ship Design.
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esrdc Ship notional baseline medium voltage direct current mvdc architecture thermal simulation and visualization
GCMS '11 Proceedings of the 2011 Grand Challenges on Modeling and Simulation Conference, 2011Co-Authors: J. V. C. Vargas, Tim Chiocchio, Julie Chalfant, Jeferson Avila Souza, Rob Hovsapian, Juan C. Ordonez, Chryssostomos ChryssostomidisAbstract:This work presents a fast visualization and thermal simulation tool developed as part of the Electric Ship Research and Development Consortium (ESRDC) funded by the Office of Naval Research (ONR) that is capable of providing quick responses during early stages of Ship Design. The tool allows for the visualization of thermal and electrical loads, and equipment locations and other variables of interest in the all-electric Ship, proceeding to the computation of the resulting whole Ship temperature and relative humidity distribution. For that, a previously developed simplified physical model [1-3] -- which combines principles of classical thermodynamics and heat transfer, resulting in a system of three-dimensional differential equations which are discretized in space using a three-dimensional cell centered finite volume scheme -- is enhanced to include fresh and sea water cooled systems throughout the Ship. Therefore, the combination of the proposed simplified physical model with the adopted finite volume scheme for the numerical discretization of the differential equations is called a volume element model (VEM). A 3D simulation is performed in order to determine the temperature distribution inside the Ship for the baseline Medium Voltage Direct Current (MVDC) architecture, and representative operating conditions are analyzed. VisIt visualization tool [4] is used to plot the results.
Christopher G. Hart - One of the best experts on this subject based on the ideXlab platform.
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An integrated multidisciplinary particle swarm optimization approach to conceptual Ship Design
Structural and Multidisciplinary Optimization, 2010Co-Authors: Christopher G. Hart, Nickolas VlahopoulosAbstract:A particle swarm optimization (PSO) solver is developed based on theoretical information available from the literature. The implementation is validated by utilizing the PSO optimizer as a driver for a single discipline optimization and for a multicriterion optimization and comparing the results to a commercially available gradient based optimization algorithm, previously published results, and a simple sequential Monte Carlo model. A typical conceptual Ship Design statement from the literature is employed for developing the single discipline and the multicriterion benchmark optimization statements. In the main new effort presented in this paper, an approach is developed for integrating the PSO algorithm as a driver at both the top and the discipline levels of a multidisciplinary Design optimization (MDO) framework which is based on the Target Cascading (TC) method. The integrated MDO/PSO algorithm is employed for analyzing a multidiscipline optimization statement reflecting the conceptual Ship Design problem from the literature. Results are compared to MDO analyses performed when a gradient based optimizer comprised the optimization driver at all levels. The results, the strengths, and the weaknesses of the integrated MDO/PSO algorithm are discussed as related to conceptual Ship Design.
