Eight decreasing adverse pressure gradient flows, and the similar regions of an initially increasing adverse pressure gradient flow, are examined in terms of the two experimentally observed half-power regions. The existing semi-empirical and analytical mean velocity profiles are examined and their range of applicability is determined in terms of the ratio of outer to inner half-power slopes. Three variations of the k-e model of turbulence are evaluated in terms of how well they predict the turbulence field in an eight degree conical diffuser. The model of Nagano and Tagawa (1990) is seen to be superior to the others. It is possible for Nagano and Tagawa’s model to yield reasonable prediction of k and E because they implemented the Hanjalic and Launder (1980) modification for the irrotational strains. However, the k-e models prediction of the Reynolds stresses is poor. / Thesis / Master of Engineering (ME)

京都大学 / 0048 / 新制・課程博士 / 博士(工学) / 甲第20344号 / 工博第4281号 / 新制||工||1663(附属図書館) / 京都大学大学院工学研究科社会基盤工学専攻 / (主査)教授 白土 博通, 教授 八木 知己, 教授 KIM Chul-Woo, 教授 杉浦 邦征 / 学位規則第4条第1項該当 / Doctor of Philosophy (Engineering) / Kyoto University / DFAM

This research provides a detailed and systematic update of the traditional sailboat design process, with specific attention being paid to the tools used for evaluation purposes, and in doing so creates an improved and optimized design process for sailboats. More specifically, this report seeks to modify a systems-engineering approach to the ship design process, in order to properly incorporate modern sailboat evaluation techniques as well as elements of traditional sailboat design while providing analysis of a case study from Virginia Polytechnic Institute and State University's ocean vehicle design class. In considering all intricacies of sailboat design and with applications and gradual improvement in quality of design through the use of multi-objective optimization methods, a new sailboat design process evolves, which initially considers a wide variety of design options and alternatives. Specific attention is paid in this process to the evolution of the ordering and analysis of each segment of the subprocesses, reducing design risk through the use of industry standard assessment procedures and ensuring consistent interaction with the customer. In doing so, an improved and effective design process is established, to be used by future sailboat design teams at Virginia Polytechnic Institute and State University. / Master of Science / Boats and marine vehicles of different types have long been a mainstay in the growth and development of this country's military, economic and transportation infrastructure. Whether being used for fishing purposes in the Pacific Northwest or moving oil and gas to different cities along the eastern seaboard, marine transportation plays a critical role in day to day life. Long before the invention of gasoline powered engines, most boats were powered by wind which was harnessed by the use of sails. In the 1800's sailboats were used extensively for fishing, delivering mail and a number of other important activities. Nowadays, the use of sailboats is more geared towards recreational endeavors including racing or simply cruising local waterways. It is the responsibility of the sailboat designer to deliver options and products commensurate with the prospective owner's preferences. As such, it is important for the designer to develop a process or system which incorporates useful tools which can successfully evaluate design alternatives. In doing so, useful information will be produced by which the owner and designer can collaboratively make decisions. Unlike a military or commercial ship, the owner of a sailboat is most likely the main operator and shares a personal connection with the boat. This study modifies a systems-engineering approach to the ship design process, in order to properly incorporate modern sailboat evaluation techniques as well as elements of traditional sailboat design. In doing so, the operation provides a process and tool benchmark for future sailboat design teams at Virginia Polytechnic Institute and State University.

Accurate prediction of performance is an important aspect of modern sailing yacht design and provides a competitive advantage on the racecourse and in the marketplace. Although wind tunnel testing of yacht sails is a common tool for obtaining input data for Velocity Prediction Programs, its results have not been validated against aerodynamic full-scale measurements as quality full-scale data is rare. Wind tunnel measurements are conducted at the Twisted Flow Wind Tunnel of The University of Auckland and are compared to the full-scale aerodynamic force measurements from the Berlin Sail-Force-Dynamometer. To realise this comparison wind tunnel techniques and aerodynamic force models for yacht sails are enhanced; this in turn also improves the accuracy of Velocity Prediction Programs. Force and surface pressure measurements were conducted demonstrating that the interaction of the hull/deck with the sails has a significant effect on the side force and the force perpendicular to the deck plane, and that this should be considered in aerodynamic analysis of sails and the performance prediction of yachts. The first Real-Time Velocity Prediction Program for wind tunnel testing has been developed and implemented as an additional module of FRIENDSHIP-Equilibrium. Model sails can now be trimmed based on the full-scale performance of the yacht, and at the correct heel angle, which makes the trimming process in the wind tunnel much more similar to the real life situation. Improved aerodynamic force models have been developed from realistically depowered sail trims obtained with the Real-Time Velocity Prediction Program. An empirical model that describes the force and moment changes due to depowering in detail has been developed and implemented. The standard semi-empirical trim parameter model, which expresses depowering in a more generic way, has been enhanced based on aerodynamic principles and validated against the wind tunnel results. Utilising the enhanced wind tunnel techniques and aerodynamic force models, a generally good qualitative and quantitative agreement with the full-scale data is achieved. Remaining challenges associated with full-scale and wind tunnel tests are however also highlighted and, based on this work alone, a conclusive judgement that scaling effects are negligible cannot be made. / Whole document restricted, but available by request, use the feedback form to request access. / IPENZ Craven Scholarship; The University of Auckland Yacht Research Unit Scholarship; The University of Auckland Graduate Research Fund

Accurate prediction of performance is an important aspect of modern sailing yacht design and provides a competitive advantage on the racecourse and in the marketplace. Although wind tunnel testing of yacht sails is a common tool for obtaining input data for Velocity Prediction Programs, its results have not been validated against aerodynamic full-scale measurements as quality full-scale data is rare. Wind tunnel measurements are conducted at the Twisted Flow Wind Tunnel of The University of Auckland and are compared to the full-scale aerodynamic force measurements from the Berlin Sail-Force-Dynamometer. To realise this comparison wind tunnel techniques and aerodynamic force models for yacht sails are enhanced; this in turn also improves the accuracy of Velocity Prediction Programs. Force and surface pressure measurements were conducted demonstrating that the interaction of the hull/deck with the sails has a significant effect on the side force and the force perpendicular to the deck plane, and that this should be considered in aerodynamic analysis of sails and the performance prediction of yachts. The first Real-Time Velocity Prediction Program for wind tunnel testing has been developed and implemented as an additional module of FRIENDSHIP-Equilibrium. Model sails can now be trimmed based on the full-scale performance of the yacht, and at the correct heel angle, which makes the trimming process in the wind tunnel much more similar to the real life situation. Improved aerodynamic force models have been developed from realistically depowered sail trims obtained with the Real-Time Velocity Prediction Program. An empirical model that describes the force and moment changes due to depowering in detail has been developed and implemented. The standard semi-empirical trim parameter model, which expresses depowering in a more generic way, has been enhanced based on aerodynamic principles and validated against the wind tunnel results. Utilising the enhanced wind tunnel techniques and aerodynamic force models, a generally good qualitative and quantitative agreement with the full-scale data is achieved. Remaining challenges associated with full-scale and wind tunnel tests are however also highlighted and, based on this work alone, a conclusive judgement that scaling effects are negligible cannot be made. / Whole document restricted, but available by request, use the feedback form to request access. / IPENZ Craven Scholarship; The University of Auckland Yacht Research Unit Scholarship; The University of Auckland Graduate Research Fund

Accurate prediction of performance is an important aspect of modern sailing yacht design and provides a competitive advantage on the racecourse and in the marketplace. Although wind tunnel testing of yacht sails is a common tool for obtaining input data for Velocity Prediction Programs, its results have not been validated against aerodynamic full-scale measurements as quality full-scale data is rare. Wind tunnel measurements are conducted at the Twisted Flow Wind Tunnel of The University of Auckland and are compared to the full-scale aerodynamic force measurements from the Berlin Sail-Force-Dynamometer. To realise this comparison wind tunnel techniques and aerodynamic force models for yacht sails are enhanced; this in turn also improves the accuracy of Velocity Prediction Programs. Force and surface pressure measurements were conducted demonstrating that the interaction of the hull/deck with the sails has a significant effect on the side force and the force perpendicular to the deck plane, and that this should be considered in aerodynamic analysis of sails and the performance prediction of yachts. The first Real-Time Velocity Prediction Program for wind tunnel testing has been developed and implemented as an additional module of FRIENDSHIP-Equilibrium. Model sails can now be trimmed based on the full-scale performance of the yacht, and at the correct heel angle, which makes the trimming process in the wind tunnel much more similar to the real life situation. Improved aerodynamic force models have been developed from realistically depowered sail trims obtained with the Real-Time Velocity Prediction Program. An empirical model that describes the force and moment changes due to depowering in detail has been developed and implemented. The standard semi-empirical trim parameter model, which expresses depowering in a more generic way, has been enhanced based on aerodynamic principles and validated against the wind tunnel results. Utilising the enhanced wind tunnel techniques and aerodynamic force models, a generally good qualitative and quantitative agreement with the full-scale data is achieved. Remaining challenges associated with full-scale and wind tunnel tests are however also highlighted and, based on this work alone, a conclusive judgement that scaling effects are negligible cannot be made. / Whole document restricted, but available by request, use the feedback form to request access. / IPENZ Craven Scholarship; The University of Auckland Yacht Research Unit Scholarship; The University of Auckland Graduate Research Fund

Accurate prediction of performance is an important aspect of modern sailing yacht design and provides a competitive advantage on the racecourse and in the marketplace. Although wind tunnel testing of yacht sails is a common tool for obtaining input data for Velocity Prediction Programs, its results have not been validated against aerodynamic full-scale measurements as quality full-scale data is rare. Wind tunnel measurements are conducted at the Twisted Flow Wind Tunnel of The University of Auckland and are compared to the full-scale aerodynamic force measurements from the Berlin Sail-Force-Dynamometer. To realise this comparison wind tunnel techniques and aerodynamic force models for yacht sails are enhanced; this in turn also improves the accuracy of Velocity Prediction Programs. Force and surface pressure measurements were conducted demonstrating that the interaction of the hull/deck with the sails has a significant effect on the side force and the force perpendicular to the deck plane, and that this should be considered in aerodynamic analysis of sails and the performance prediction of yachts. The first Real-Time Velocity Prediction Program for wind tunnel testing has been developed and implemented as an additional module of FRIENDSHIP-Equilibrium. Model sails can now be trimmed based on the full-scale performance of the yacht, and at the correct heel angle, which makes the trimming process in the wind tunnel much more similar to the real life situation. Improved aerodynamic force models have been developed from realistically depowered sail trims obtained with the Real-Time Velocity Prediction Program. An empirical model that describes the force and moment changes due to depowering in detail has been developed and implemented. The standard semi-empirical trim parameter model, which expresses depowering in a more generic way, has been enhanced based on aerodynamic principles and validated against the wind tunnel results. Utilising the enhanced wind tunnel techniques and aerodynamic force models, a generally good qualitative and quantitative agreement with the full-scale data is achieved. Remaining challenges associated with full-scale and wind tunnel tests are however also highlighted and, based on this work alone, a conclusive judgement that scaling effects are negligible cannot be made. / Whole document restricted, but available by request, use the feedback form to request access. / IPENZ Craven Scholarship; The University of Auckland Yacht Research Unit Scholarship; The University of Auckland Graduate Research Fund

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Mobility is a topic of great interest in research and engineering since critical aspects such as safety, traffic efficiency, and environmental sustainability still represent wide open challenges for researchers and engineers. In this thesis, at first, we address the cooperative driving safety problem both from a centralized and decentralized perspective. Then we address the problem of optimal energy management of hybrid vehicles to improve environmental sustainability, and finally, we develop an intersection management systems for Connected Autonomous Vehicle to maximize the traffic efficiency at an intersection. To address the first two topics, we define a common framework. Both the cooperative safety and the energy management for Hybrid Electric Vehicle requires to model the driver behavior. In the first case, we are interested in evaluating the safety of the driver’s intentions, while in the second case, we are interested in predicting the future velocity profile to optimize energy management in a fixed time horizon. The framework is the Co-Driver, which is, in short, a bio-inspired agent able both to model and to imitate a human driver. It is based on a layered control structure based on the generation of atomic human-like longitudinal maneuvers that compete with each other like affordances. To address driving safety, the Co-Driver behaves like a safe driver, and its behavior is compared to the actual driver to understand if he/she is acting safely and providing warnings if not. In the energy management problem, the Co-Driver aims at imitating the driver to predict the future velocity. The Co-Driver generates a set of possible maneuvers and selects one of them, imitating the action selection process of the driver. At first, we address the problem of safety by developing and investigating a framework for Advanced Driving Assistance Systems (ADAS) built on the Co-Driver. We developed and investigated this framework in an innovative context of new intelligent road infrastructure, where vehicles and roads communicate. The infrastructure that allows the roads to interact with vehicles and the environment is the topic of a research project called SAFESTRIP. This project is about deploying innovative sensors and communication devices on the road that communicate with all vehicles. Including vehicles that are equipped with Vehicle-To-Everything (V2X) technology and vehicles that are not, using an interface (HMI) on smart-phones. Co-Driver-based ADAS systems exploit connections between vehicles and (smart) roads provided by SAFESTRIP to cover several safety-critical use cases: pedestrian protection, wrong-way vehicles on-ramps, work-zones on roads and intersections. The ADAS provide personalized warning messages that account for the adaptive driver behavior to maximize the acceptance of the system. The ability of the framework to predict human drivers’ intention is exploited in a second application to improve environmental sustainability. We employ it to feed with the estimated speed profile a novel online Model Predictive Control (MPC) approach for Hybrid Electric Vehicles, introducing a state-of-the-art electrochemical model of the battery. Such control aims at preserving battery life and fuel consumption through equivalent costs. We validated the approach with actual driving data used to simulate vehicles and the power-train dynamics. At last, we address the traffic efficiency problem in the context of autonomous vehicles crossing an intersection. We propose an intersection management system for Connected Autonomous Vehicles based on a bi-level optimization framework. The motion planning of the vehicle is provided by a simplified optimal control problem, while we formulate the intersection management problem (in terms of order and timing) as a Mixed Integer Non-Linear Programming. The latter approximates a linear problem with a powerful piecewise linearization technique. Therefore, thanks to this technique, we can bound the error and employ commercial solvers to solve the problem (fast enough). Finally, this framework is validated in simulation and compared with the "Fist-Arrived First-Served" approach to show the impact of the proposed algorithm.