Littérature scientifique sur le sujet « Multi-physic design »

Silicon solar cell is well known as one of the cleanest and most potential renewable resources. As the major photovoltaic (PV) material in PV industry, multi-crystalline silicon (mc-Si) grown by directional solidification has recently attracted increasing attention because of its low production cost, low pollution and high throughput. Deeper understanding of the physic and optic properties, and preparation methods of the materials will lead to improved device design. This paper briefly presents basic directional solidification theory of multi-crystalline silicon, and reviews recent development of solar-grade multi-crystalline silicon. The directional solidification preparation techniques of high-quality solar-grade multi-crystalline silicon are detailed introduced and summarized. Furthermore, the existing problems and further development direction of directionally solidified multi-crystalline silicon for solar cell are discussed.

The new virtual modelling tool is constructed, which is used for optimal design of power transmission lines and cables. The construction of such lines should meet the latest power transmission network technical and economical requirements. The solver is is based on classical and modified mathematical models describing main heat conduction processes: diffusion, convection and radiation in various materials and environments. In basic heat conduction equation, we take into account a linear dependence of the resistance on temperature. Multi-physic and multi-scale models are required to simulate industrial cases of power transmission lines. The velocity of convective transport of the heat in air regions is simulated by solving a coupled thermo-convection problem including the heat conduction problem and the standard Navier-Stokes model of the heat flow in air. Another multi-physic model is used to describe changes of material heat conduction coefficients in soil due to influence of heating. This process is described by by solving a simplified mass balance equation for flows in porous media. The multi-scale and homogenization analysis is required to to formulate simple and accurate mathematical describing heat conduction process is metal region which consists of a bundle of tightly coupled metal wires. The FVM is used to solve the obtained systems of differential equations. Discretization of the domain is done by applying “aCute” mesh generator, which is a modification of the well-known Triangle mesh generator. The discrete schemes are implemented by using the OpenFOAM tool.

With the introduction of the closed-loop shaping filtering method into the L2 gain robust controller design strategy, a nonlinear robust steering controller for unmanned surface vessel is designed under the planning and control strategy in this paper. The rigorous mathematical analysis and synthesis characteristics of the L2 gain robust control theory and the Lyapunov design method are fully utilized in the controller design process. Furthermore, the concept of the closed-loop shaping filtering based on the classical closed-loop control theory is taken into the controller design strategy. Therefore, the time domain controller design methods integration with the frequency domain controller design strategy are merged togehter to complete the unmanned surface vessel steering controller design in the view of practical engineering and planning and control strategy. Finally, compared with several practical controller design methods in the multi-direction irregular waves, the simulation results show that the proposed steering controller design strategy has concise structure, distinctive physic meanings of the controller parameters and superior comprehensive control performance.

There is society awerness in helat life style that makes consumer is more selective in choosing consumed vegetable. The hydroponic vegetable product that is free from pesticide becomes an alternative for consumer, which have health life style. The research aims at knowing how consumer preference toward hydroponic vegetable and knowing how consumer attitude toward a vegetable hydroponic attribute that is most consideration in a purchase decision. The research applied a descriptive method. Total respondents that were studied as much as 50 people by applying purposive sampling. Analysis design applied descriptive statistic and attitude analysis of fishbein multi-attribute. The resulting research declares consumer prefer hydroponic vegetable that has fresh level < 3 days, has a physical wide leaf which has no hole, different taste with conventional vegetable, type variety > 3 types, price < 5.000 IDR, and vegetable in the plastic package. The most consumer consideration attribute in purchase decision respectively is vegetable fresh level, leaf physic, package, vegetable taste, price, and type variety. The most vegetable type that is prefered by the consumer in pakcoy.

Background/Objectives: Recently, it has been great issue to transfer large-scale science dada such as scientific field of high energy physic, astronomical space, super-computing simulation. To solve the transfer issue and to increase transfer efficiency, it needs a multi-dimensional approaches.Methods/Statistical analysis: To improve the transfer performance, approaches from the perspective of components such as network equipment, transmission protocol, and transmission application have been suggested. Effort to TCP congestion control algorithm and parallelism of data transfer channel are representative example to improve performance. However, the solution through the each component has a limitation in maximizing the transmission efficiency.Findings: Science DMZ is a new network architecture that can maximize transfer performance. It maximizes transfer efficiency through approach to all components, such as network equipment, dedicated network path, transfer applications, and local institute firewall policies. With these complicated components, science DMZ network architecture can greatly improve the transfer efficiency. In this paper, we design and construct a science DMZ network architecture between two organizations that utilize supercomputing resources based on KREONET and evaluate the performance.Improvements/Applications: After configuring the experiment environment, we measured network performance through iperf and file transfer performance test through SCP. Experiment result showed around 388% Improvement than that of existing method.

PurposeThis paper aims to present two mathematical models to solve the Energy Management problem of a building microgrid (MG). In particular, it proposes a deterministic mixed integer linear programming (MILP) and non-linear programming (NLP) formulations. This paper focuses on the modelling process and the optimization performances for both approaches regarding optimal operation of near-zero energy buildings connected to an electric MG with a 24-h time horizon. Design/methodology/approachA general architecture of a MG is detailed, involving energy storage systems, distributed generation and a thermal reduced model of the grid-connected building. A continuous non-linear model is detailed along with linearizations for the mixed-integer liner formulation. Multi-physic, non-linear and non-convex phenomena are detailed, such as ventilation and air quality models. FindingsResults show that both approaches are relevant for solving the energy management problem of the building MG. Originality/valueIntroduction and modelling of the thermal loads within the MG. The resulting linear program handles the mutli-objective trade-off between discomfort and the cost of use taking into account air quality criterion. Linearization and modelling of the ventilation system behaviour, which is generally non-linear and non-convex equality constraints, involving air quality model, heat transfer and ventilation power. Comparison of both MILP and NLP methods on a general use case provides a solution that can be interpreted for implementation.

Nutrition fulfill was an important thing to be considered in increasing the nutrition status of under-fives, because under five years old children had rapid growth phase. Therefore, the intake of nutrition need to get more attention. The purpose of this research was to analyze the correlation between self-efficacy of mother from poor families with nutritional parenting pattern of under-fives in the area of Mojokerto Regency East Java. The research design used case control with case population which was poor mother with healthy under-fives and control population was poor mother with under-fives who had nutritional problems. The number of sample was 79 people for case group and 41 people for control group. The sampling technique used multi stage sampling. The data collection used questionnaire which had beed tested the validity and reliability to 30 people. The data analysis used statistic chi square test. The research result showed that the correlation of self-efficacy with good parenting pattern as many as 68 people (81,0%) the analysis result with chi square obtained uji p = 0,000, self-efficacy with good love pattern as many as 52 people (61,9 %) the result analysis with chi square test obtained p = 0,000, self-efficacy with sharpening pattern as many as 57 people (67,9%) the analysis result of chi square test obtained p = 0,000, self-efficacy with nutritional parenting pattern as many as 44 people (52,4%) the result of analysis with chi square test obtained p = 0.001, value of α = 0,05, meant there was correlation between self-efficacy with nutritional parenting pattern of under-fives. The nutritional parenting of under-fives was important to be considered because it had huge impact and prolonged impact on health status, physic and mental development, and also the productivity of children when they grew up, so self-efficacy was needed to give nutrition to their under-fives.

Depuis la fermeture de Phénix en 2010 le CEA ne possède plus de réacteur au sodium. Vus les enjeux énergétiques et le potentiel de la filière, le CEA a lancé un programme de démonstrateur industriel appelé ASTRID (Advanced Sodium Technological Reactor for Industrial Demonstration), réacteur d’une puissance de 600MW électriques (1500 MW thermiques). L’objectif du prototype est double, être une réponse aux contraintes environnementales et démontrer la viabilité industrielle :• De la filière RNR-Na, avec un niveau de sureté au moins équivalent aux réacteurs de 3ème génération, du type de l’EPR. ASTRID intégrera dès la conception le retour d’expérience de Fukushima ;• Du retraitement des déchets (transmutation d’actinide mineur) et de la filière qui lui serait liée.La sûreté de l’installation est prioritaire, aucun radioélément ne doit être rejeté dans l’environnement, et ce dans toutes les situations. Pour atteindre cet objectif, il est impératif d’anticiper l’impact des nombreuses sources d’incertitudes sur le comportement du réacteur et ce dès la phase de conception. C’est dans ce contexte que s’inscrit cette thèse dont l’ambition est le développement de nouvelles méthodes d’optimisation des cœurs des RNR-Na. L’objectif est d’améliorer la robustesse et la fiabilité des réacteurs en réponse à des incertitudes existantes. Une illustration sera proposée à partir des incertitudes associées à certains régimes transitoires dimensionnant. Nous utiliserons le modèle ASTRID comme référence pour évaluer l’intérêt des nouvelles méthodes et outils développés.L’impact des incertitudes multi-Physiques sur le calcul des performances d’un cœur de RNR-Na et l’utilisation de méthodes d’optimisation introduisent de nouvelles problématiques :• Comment optimiser des cœurs « complexes » (i.e associés à des espaces de conception de dimensions élevée avec plus de 20 paramètres variables) en prenant en compte les incertitudes ?• Comment se comportent les incertitudes sur les cœurs optimisés par rapport au cœur de référence ?• En prenant en compte les incertitudes, les réacteurs sont-Ils toujours considérés comme performants ?• Les gains des optimisations obtenus à l’issue d’optimisations complexes sont-Ils supérieurs aux marges d’incertitudes (qui elles-Mêmes dépendent de l’espace paramétrique) ?La thèse contribue au développement et à la mise en place des méthodes nécessaires à la prise en compte des incertitudes dans les outils de simulation de nouvelle génération. Des méthodes statistiques pour garantir la cohérence des schémas de calculs multi-Physiques complexes sont également détaillées.En proposant de premières images de cœur de RNR-Na innovants, cette thèse présente des méthodes et des outils permettant de réduire les incertitudes sur certaines performances des réacteurs tout en les optimisant. Ces gains sont obtenus grâce à l’utilisation d’algorithmes d’optimisation multi-Objectifs. Ces méthodes permettent d’obtenir tous les compromis possibles entre les différents critères d’optimisations comme, par exemple, les compromis entre performance économique et sûreté
Since Phenix shutting down in 2010, CEA does not have Sodium Fast Reactor (SFR) in operating condition. According to global energetic challenge and fast reactor abilities, CEA launched a program of industrial demonstrator called ASTRID (Advanced Sodium Technological Reactor for Industrial Demonstration), a reactor with electric power capacity equal to 600MW. Objective of the prototype is, in first to be a response to environmental constraints, in second demonstrates the industrial viability of:• SFR reactor. The goal is to have a safety level at least equal to 3rd generation reactors. ASTRID design integrates Fukushima feedback;• Waste reprocessing (with minor actinide transmutation) and it linked industry.Installation safety is the priority. In all cases, no radionuclide should be released into environment. To achieve this objective, it is imperative to predict the impact of uncertainty sources on reactor behaviour. In this context, this thesis aims to develop new optimization methods for SFR cores. The goal is to improve the robustness and reliability of reactors in response to existing uncertainties. We will use ASTRID core as reference to estimate interest of new methods and tools developed.The impact of multi-Physics uncertainties in the calculation of the core performance and the use of optimization methods introduce new problems:• How to optimize “complex” cores (i.e. associated with design spaces of high dimensions with more than 20 variable parameters), taking into account the uncertainties?• What is uncertainties behaviour for optimization core compare to reference core?• Taking into account uncertainties, optimization core are they still competitive? Optimizations improvements are higher than uncertainty margins?The thesis helps to develop and implement methods necessary to take into account uncertainties in the new generation of simulation tools. Statistical methods to ensure consistency of complex multi-Physics simulation results are also detailed.By providing first images of innovative SFR core, this thesis presents methods and tools to reduce the uncertainties on some performance while optimizing them. These gains are achieved through the use of multi-Objective optimization algorithms. These methods provide all possible compromise between the different optimization criteria, such as the balance between economic performance and safety

High speed aerostatic spindles operating at a speed up to 200,000 r/min are a complex product with a multi-physics nature resulted from embedded mechanical-thermal-fluidic-electromagnetic fields. It is much needed to have a comprehensive analysis on the multi-physic interactions within a high speed aerostatic spindle, which is essential for design of the spindles working at much higher speeds and accuracy in various increasingly stringent engineering conditions. This paper presents a multi-physics integrated modelling approach for design and analysis of the high speed aerostatic spindle, including thermal, electromagnetic, mechanical and fluidic analysis models. The heat source, heat transfer mechanism and heat sinks of the spindle system are comprehensively investigated. Furthermore, air film pressure distribution is studied to lead to optimal design and analysis of loading capacity and stiffness of the aerostatic bearings. The multi-physics modelling is implemented using the CFD-FEA integrated approach and validated experimentally. It is shown that the multi-physics integrated modelling is able to simulate the performance characteristics of the spindle system accurately.

Nowadays in many industrial applications, i.e. electrical household appliances, it is necessary to have a robust and safe control for some variables involved in the analysis of the performances of different products. In addition, the recent eco-design directives require products increasingly eco-friendly and eco-efficient, preserving high-performance but a low power consumption. For these reasons, the physical prototypes of products require many expensive and complex tests in term of time, resources and qualified personnel involved. To overcome these limitations, the proposed approach is focused on the use of virtual prototyping tools, which support and reduce the expensive physical experiments. The main objective of this paper is the development, implementation and testing of an innovative methodology, which could be an improvement for the sustainable design of induction hobs. Induction heating applied to the domestic cooking has significantly evolved since the first cooking hobs appeared. Different issues such as maximum power available for heating a pot, dimensional compactness of the hobs, or inverter electronics efficiency have achieved a great development. The proposed methodology provides the development of a multi-physic model which is able to estimate the efficiency of the induction hobs starting from the design data of the project. In particular, the multi-physic model is composed by an electromagnetic simulation and a thermal simulation. The electromagnetic simulation, starting from electrical values such as voltage, current and frequency, is able to simulate the eddy current induced in the bottom of the pot, and resistance leads to the Joulean heating of the material. The thermal simulation is able to measure the energy consumption during the operational phase and the temperature reached by the materials. Therefore, the thermal power obtained by the Joulean heating is, at the same time, the output of the electromagnetic simulation and the input of the thermal one. The proposed model can be applied to design product and simulate the performance considering different operating conditions such as different types of cookers, different coils and different materials. Through the use of virtual prototyping tools is possible to control the heat flux on the whole system (stove, pot, water), and to evaluate the energy efficiency during the operational phase. The proposed tool makes the product-engineer more aware about decision-making strategies in order to achieve an energy saving, calculated over the whole life cycle.

The present paper is concerned with the numerical simulation of magneto-hydrodynamic (MHD) problems with industrial tools. MHD has received attention some thirty to twenty years ago as a possible alternative in propulsion applications; MHD propelled ships have even been designed to that purpose. However such propulsion systems have been proved of low efficiency and fundamental researches in the area have progressively received much less attention over the past decades. Numerical simulation of MHD problem could however provide interesting solutions in the field of turbulent flow control. The development of recent efficient numerical techniques for multi-physic applications provide promising tool for the engineer for that purpose. In the present paper, some elementary test cases in laminar flow with magnetic forcing terms are analyzed; equations of the coupled problem are exposed and analytical solutions are derived in each case, highlighting the relevant non-dimensional number which drives the physics of the problem. Several analytical calculations are then proposed and discussed. The present work will serve as basis for validation of numerical tools (based on the finite element method) for academic as well as industrial application purposes.