Patrick Sebastian

Patrick Sebastian
University of Bordeaux · Department of Science and Technology

PhD

About

90
Publications
24,282
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954
Citations
Additional affiliations
October 1993 - present
University of Bordeaux
Position
  • Professor (Assistant)

Publications

Publications (90)
Article
Free cooling systems based on phase change materials (PCM) are a possible alternative to air conditioning systems for summer comfort in buildings. However, the performance of such cooling systems is closely related to the climatic conditions and building configurations to be cooled. The objective of this work is to present an application of multiob...
Article
Due to the increasing energy use and greenhouse gas emissions related to HVAC applications in the residential sector, thermal energy storage with phase change materials has caught considerable attention in the last years. Their attractive storage capacity can be adapted to meet the energy needs of buildings. In this work, the design process of a pr...
Article
This study describes the development of a process model combining a biomass energy conversion unit with a cereal‐based products’ dryer. Heat and mass transfer and pressure drops, which occur during the process, are identified using two experimental set‐ups. The tool can predict the behavior of a heat exchanger and simulate drying of agglomerated pr...
Article
This paper presents experimental results of an air-PCM heat exchanger, with an in-line arrangement of cylindrical containers. The objective is to highlight the physical phenomena occurring in a single container during the phase change. Temperature and airflow measures were carried out. These values were used to find the heat exchanges on the contai...
Article
Full-text available
In recent years, flash evaporation processes have received an increased attention in the wine industry for must concentration applications. Specific constraints related to the wine industry area had lead to many improvements of flash evaporators initially designed for seawater desalination. In particular the quality of the vintage, the transportabi...
Article
The allocation of design and manufacturing tolerances has a significant effect on the final performance of products and the associated manufacturing costs. Although this phase is crucial in the early stages of product design, there is a lack of tools to provide support for designers. The main originality of this study is to propose an integrated op...
Conference Paper
Full-text available
The adaptability and potentially interesting performance of the air-cooling systems using thermal energy storage (TES) with phase change materials (PCM) are features that have contributed to their development. These systems can help to manage the energy use, by storing the surplus heat of a building during the day, and then, during the night, relea...
Article
Air cooling systems that make use of the energy storage potential of the latent heat of Phase Change Materials (PCMs) are alternatives to conventional air-conditioning units for maintaining indoor comfort in summer in light-weight buildings. However, the functioning of such systems is closely linked to the ambient climatic conditions and to the spa...
Conference Paper
Full-text available
Short Abstract: This paper reviews the development of the studies carried out by the Mechanics and Engineering Institute of Bordeaux (I2M), in the design, manufacturing and optimization of LHTES systems using PCM. A selection process mainly based on the encapsulated parameters is shown for each case, which allows to observe the evolution path of th...
Article
This study aims to show the preliminary results of an improved components and characteristics of heat exchanger air and Phase Change Material (PCM)that was designed, dimensioned, manufactured and tested in the laboratory (with melting temperature ranging between 27-29° C), especially for refreshing semi-passive air in summer period. The preliminary...
Article
This paper presents a multiobjective optimization method specifically adapted to the design of food processes. It is illustrated with the design of an innovative radiant plate hot-smoking process, for the joint optimization of the design objectives of product quality, energetic performances and production performances. The design variables concern...
Article
Energy availability, heat conversion and transfer still represent an impediment to the food processing sector in developing countries. Optimisation of tubular heat exchangers remains a concern for equipment designers and manufacturers. This work assesses the performances of a turbulator in terms of heat transfer and fluid friction characteristics i...
Article
This paper fully describes a simulation model of the radiant-plate hot smoking process, adapted to design optimization. A simulation model from previous work is improved with some features which mainly concern heat and mass transfers, pressure losses, drying air recycling and fish drying behavior. For the purpose of preliminary design, the industri...
Conference Paper
Full-text available
The purpose of this work is the food process design optimization for the production of African traditional hot-smoked products. Based on a methodology of interpretation and aggregation of multiple industrial constraints, a multi-objective decision tool is developed for improving the technological performances of productivity, energy efficiency and...
Article
A real-scale Latent Heat Thermal Energy Storage (LHTES) device has been designed and set up for air-cooling in the housing sector. This system uses the thermal gap between night-time and daytime outdoor air to refresh the indoor air. The air passes along a box-section horizontal tube bundle filled with paraffin wax (Phase Change Material). To devel...
Article
This work aims at evaluating the mass reduction of traditionally hot-smoked catfish ( Arius heudelotii ) during hot-air drying unit operation. Drying kinetics of fish fillets are proposed from experimental investigations, taking into account the relative contributions of water evaporation and water and fat drips. The influence of the air temperatur...
Article
The air conditioning market is in constant growth, which can lead to peak loads in electricity grids during summertime. To overcome such problems, Latent Heat Thermal Energy Storage (LHTES) systems can be used for summer comfort in lightweight buildings. These systems consume little energy by using the temperature gap between daytime and night-time...
Article
Full-text available
Designing high performance cooling systems suitable for preserving the service lifetime of nozzle guide vanes of turboshaft engines leads to significant aerodynamic losses. These losses jeopardize the performance of the whole engine. In the same time, a low efficiency cooling system may affect the costs of maintenance repair and overhaul of the eng...
Conference Paper
Full-text available
Un prototype d'échangeur-stockeur pour le rafraîchissement de l'air a été conçu, dimensionné et réalisé pour être intégré dans un prototype de maison solaire à énergie positive. Ce prototype intègre une paraffine (Matériau à Changement de Phase -MCP-) dont la transition solide/liquide s'effectue aux alentours de 21°C. Des essais en conditions de la...
Article
Le présent travail proposé, traite les systèmes énergétiques, du type photovoltaïque autonome, couplé à des batteries de stockage, et destinés à la couverture des besoins d’un foyer rural du Bénin. Ces systèmes énergétiques appropriés ont été analysés, modélisés et optimisés. Les critères d’évaluation sont issus d’une enquête réalisée auprès des re...
Article
We propose a decision support method in embodiment design, dedicated to embedded autonomous microsystems design. The main objective of our work is to go beyond battery configurations by supporting the design of autonomous microsystems, namely systems able to harvest and use available energy from their environment. The main challenge of our approach...
Article
In most industrial design processes, the approaches used to obtain a design solution that best fits the specification requirements result in many iterations of the “trial-and-error” type, starting from an initial solution. In this paper, a method is proposed to formalize the decision process in order to automate it, and to provide optimal design so...
Article
Engineering design in mechanics is a complex activity taking into account both objective modeling processes derived from physical analysis and designers’ subjective reasoning. This paper introduces arc-elastic dominance as a suitable concept for ranking design solutions according to a combination of objective and subjective models. Objective models...
Data
Full-text available
Nomenclature A Heat exchange surface (m 2) Cp Sensible heat capacity (J.kg -1 .K -1) d Diameter (m) h Heat exchange coefficient (W.m -2 .K -2) H Enthalpy (J.m -3) k Convective gain factor(-) N t Number of aluminum tubes (-) Nu Nusselt Number (-) p Perimeter (m) S Cross section (m 2) s Lateral or top distance from the PCM melting front to tube walls...
Article
During the early phases of design processes, designers have to take the best decisions in order to converge quickly toward the most preferred design solution. More precisely, in a preliminary design context, the phase of embodiment design consists in determining the best values for the main dimensioning parameters of the system to improve its perfo...
Article
Full-text available
In this paper, an original trade-off function is proposed to deal with robust design in engineering. Robust design in engineering aims at sizing systems with a low variation in all performance measures under uncertainties. It is mainly related to the generation and evaluation of candidate solutions. However, it is also suitable to consider the robu...
Article
In the industrial design process, “trial-and-error” loops are usually used between design departments and simulation departments, to design and validate a candidate solution. Such a solution is defined by instantiated design variables, characterizing the main parameters of the product. This paper proposes to replace the trial-and-error process by a...
Article
Full-text available
In aeronautics, the decreased density of structural components is a major factor to consider in order to satisfy economic, environmental, and technical requirements. Using composite materials is justifying good weight to mechanical strength compromise. Mechanical strength depends on shapes, dimensions, and materials defined at the design stage and...
Article
In recent years, flash evaporation processes have received increased attention in particular areas such as the wine industry where evaporators are mainly used for flash-cooling or concentration. Faced with specific constraints relating to these new areas of application, the design of flash evaporators must now take into account multiple design obje...
Article
Flash evaporation process is currently developing in the wine industry where it is used for flash-cooling or concentration. The design of flash evaporators is faced with specific constraints and must take into account multiple design objectives. In this paper, the development of a multi-objective optimization method is investigated for the joint op...
Article
Full-text available
A key challenge for the future is to reduce drastically the human impact on the environment. In the aeronautic field, this challenge aims at optimizing the design of the aircraft to decrease the global mass. This reduction leads to the optimization of every part constitutive of the plane. This operation is even more delicate when the used material...
Article
Controlling variability and process optimization are major issues of manufacturing processes which should be tackled together since optimal processes must be robust. There is a lack of numerical tool combining optimization and robustness. In this paper, a complete approach starting from modelling and leading to the selection of robust optimal proce...
Article
A sub-unit of an aeronautical structure (fuselage, fin, wing, etc.) consists of a set of components fixed rigidly together. One of today’s major industrial challenges is to produce these sub-units out of composite materials in order to increase the level of integration and reduce mass and cost. This article describes a procedure to assist in the in...
Article
Full-text available
Embodiment design (ED) is an early phase of product development. ED problems consist of finding solution principles that satisfy product requirements such as physics behaviors and interactions between components. Constraint satisfaction techniques are useful to solve constraint-based models that are often partial, heterogeneous, and uncertain in ED...
Article
We propose a procedure for the formalization and qualification of models adapted specifically to the requirements of preliminary design. Using this methodology the current lack of suitable decision support tools for design can be overcome. Following a needs assessment for modeling during this design phase, the approach that we develop here is based...
Article
Full-text available
The embodiment design of aeronautic systems proves to be a difficult design phase due to the variability in the system environment; the design is often constrained by atmospheric conditions. These atmospheric conditions appear to be highly variable according to the flight phases of the aircraft. The difficulty when designing air-conditioning system...
Conference Paper
Full-text available
During early stages of the design process, designers investigate the design alternatives by considering several criteria and their own experience. There is a lack of tools to support decision, so a trial and error iterative design process is commonly used. Design choices are relating to continuous and discrete design variables. Therefore, the desig...
Article
The flash evaporation process uses pressure differences to cause instantaneous fluid cooling and concentration. It is thus used for shortened cooling time in the wine-making process. Although promising since it allows grape cooling and concentration in addition to improving wine quality with one single device, the development of this process remain...
Conference Paper
Full-text available
In this paper, the embodiment design of an air conditioning system (ACS) in an aircraft is investigated using interval constraint satisfaction techniques. The detailed ACS model is quite complex to solve, since it contains many coupled variables and many constraints corresponding to complex physics phenomena. Some new heuristics and notions based o...
Conference Paper
Full-text available
The embodiment design of a Joule-Brayton cycle based air-conditioning system for aircrafts (bootstrap) proves to be a difficult design problem. This difficulty is due to the variability in the system environment. For instance, atmospheric conditions are very different according to the flight phases. This difficulty is also inherent to the complexit...
Article
Recent progress has been made in the field of digital processing tools based on interval analysis dedicated to decision support in embodiment design. In this paper, the performances of an interval analysis based Constraint Satisfaction Problem (CSP) solver and a Genetic Algorithm based design code are compared and discussed. The embodiment design p...
Conference Paper
Full-text available
The design of an air-conditioning system for a commercial aircraft, which functions in various life cycle stages, proves difficult because atmospheric conditions differ greatly according to the flight phase. This paper proposes the use of constraint programming in the exploration of design spaces and the search for feasible embodiments. This approa...
Article
In this paper, a logarithmic model and Giner’s differential model are compared in the process of simulating the stationary deep-bed drying of a product. The logarithmic model can be interpreted as the propagation of boundary conditions along characteristic lines throughout the bed. This propagation depends on drying air velocity and becomes less pr...
Article
The film-boiling densification process is an alternative of chemical vapor infiltration involving a strong thermal gradient. It allows to fabricate composite materials starting from a fibrous preform lying in a boiling hydrocarbon precursor, the cracking of which results in a solid deposit constituting the matrix of the carbon/carbon composite. A m...
Conference Paper
Full-text available
The present article exemplifies the use of CSP techniques to make the embodiment design phase easier when optimising component choices and pre-dimensioning an aircraft air-conditioning system. Thus, all the solution architectures can be generated without a-priori choices being made by the designer and without applying a trial-and error method. Then...
Article
Full-text available
There has been recent interest in developing hot smoking kilns avoiding benzo(a)pyrene deposition on meat. An experimental kiln limiting this deposition phenomenon has been designed, built and tested. This kiln is used to dry, smoke and cook pork meat in order to obtain boucané, a traditional smoked product from La Réunion Island. Smoking is perfor...
Article
Full-text available
There has been recent interest in developing small-scale smoking technologies that respect French sanitary recommendations concerning benzo(a) pyrene deposition on food. The conceptual and embodiment phases of design, and the sizing of a smoker in which this deposition phenomenon is limited are reviewed in this paper. The conceptual phase of design...
Chapter
Full-text available
In the early phases of a traditional design process, many decisions are made by designers. For that purpose, they take advantage of their experience and company knowledge. These decisions are necessary in a sequential design process but may hide many embodiment solutions. Moreover, designers often use a trial-and-error mode to find a working combin...
Article
Full-text available
Early stages of the design process are often based on designers' experience; assumptions and irreversible decisions restricting the solution space are taken. It is difficult to take into account simultaneously every requirement imposed by the different phases of the product life-cycle. In this paper, a method is proposed to perform the analysis of...
Conference Paper
Full-text available
During embodiment design, the designers make technological choices which must take into account all the points of view of various participants in the project. With the classical methods of design, this work is very difficult and requires much time. We propose to use constraints programming in order to reduce the duration of the embodiment design. W...
Conference Paper
Full-text available
Important choices have to be performed in order to start the embodiment design phase, and designers call for their experiment. But these choices do not take into account simultaneously all the elements of the design problem: qualification criteria, physical behaviour, different technical skill rules of design and manufacturing… Our method (IID) all...
Article
The flash evaporation process has received growing recent interest in the agro-industry, particularly for the post-harvest treatment of grapes. This paper is devoted to the design and the optimization of a two-stage flash evaporator. An embodiment design approach of this process based on constraint satisfaction problem-solving techniques is present...
Conference Paper
Full-text available
Some difficulties arise in the early stages of design process. First, several iterations must be performed between the conceptual and the embodiment design phases before reaching design solutions. Next, in an integrated engineering context, several points of view must be taken into account. More to the point, the synthesis activity in embodiment de...