PORTFOLIO MANAGEMENT OF INNOVATION FIELDS : APPLYING CK DESIGN THEORY IN CROSS INDUSTRY EXPLORATORY PARTNERSHIP

Our paper refers to an industrial practice based on an integrated theoretical framework of design, CK design theory (Hatchuel and Weil, 2002, Hatchuel and Weil, 2003, Hatchuel and Weil, 2008), to support people in management of innovation fields. This study is based on an empirical case in a new form of R&D partnerships, the Cross Industry Exploratory Partnerships. MINATEC IDEAs Laboratory® is composed of a broad scope of partners 2 which aims to co-explore opportunities of micronanotechnologies. The paper deals with a strategic design tool, OPERA, which has been experimented since 2007 and involved participation of design team work and powerholders. During two years, creative insights and projects of the two laboratory's major innovation fields have been collected and structured within CK theory. This tool permits power-holders to drive innovation projects by giving an overview of explored concepts (and still not explored), activation and production of competencies and knowledge.CK theory; innovative design; innovation partnership; OPERA; design theory; management of innovation

Dispersion in confined building : a coupled approach

International audienceModelling gas dispersion in mechanically ventilated building is a challenge for safety engineers. A leak in such an infrastructure can generate two different consequences: toxic effect or blast effect after a flammable vapour cloud ignition. In both case, it is important to be able to predict the gas behaviour using numerical tools in order to be able to design adapted ventilation systems. Gaseous products are generally stored under pressure that induces high velocity in case of release from the tank or following a line rupture. Considering this important pressure, the jet zone is a highly complex zone with a Mach number higher than 1 that induces shock waves. These waves correspond to discontinuity of the flow. After this jet zone, a transition region (air entrainment) is observed and can be characterised by the beginning mixture of the gas with air. This also corresponds to an expansion of the jet diameter inducing a velocity decrease. Finally, after this zone, the flow becomes governed by the ventilation system where the Mach number is lower than 1. To model gas dispersion in closed enclosure, CFD models can be used. Such codes enable to predict the different physical quantities in the whole domain along time. However, most of these codes are not able to model complex phenomena such as ones that characterised the jet region. CFD codes are able to capture such a complex physic require mesh in the jet zone that is not in accordance with the objective to model the whole infrastructure considering current computing limitations. To overcome this and making achievable such modelling, a coupled approach between a 1D jet model and a CFD code is proposed. The 1D model predicts gas behaviour in the jet zone while the CFD code describes the concentration and velocity in the whole domain. The FDS CFD code was used. This code is based on the LES approach for turbulence modelling. Such an approach is highly interesting for safety because it enables not to predict an average configuration but a realistic one. Because of the well known capability of this code for predicting smoke behaviour considering ventilation, it is useful to wonder about its capability to model gas dispersion in buildings. A comparison between FDS, coupled with the 1D model, results and experimental ones are given. The experimental results were obtained in an 80 m3 room equipped with a ventilation system in which ammoniac was injected. Two different ventilation regimes were used and concentrations were measured in several locations inside the room at different heights. Comparisons between experimental and numerical values shows a great agreement and leads to the conclusion that the FDS code is a pertinent tool for gas dispersion modelling in confined building when coupling this code with a 1D jet model

Combustion rate of medium scale pool fire, an unsteady parameter

International audiencePool fire is a classical dangerous phenomenon that can occur in various infrastructures and generates different consequences. Several investigations were achieved to improve the understanding of this phenomenon from theoretical to experimental. Experimental studies have lead to a classification of fuel as a function of combustion rate. These tests are generally based on constant level fire with fuel feed at the bottom of the sample. Theoretical studies have detailed the fire heat release distribution and the impact on the liquid fuel. Based on these results, the expected evolution of the fire includes three main parts: the fire increase, a constant maximal heat release period and the fire decrease. If this evolution suits with external pool fire, behaviour of the liquid can be impacted by contextual configuration. In confined infrastructures, such as building or tunnels, the liquid fuel combustion velocity becomes an unsteady parameter and the heat release rate from the fire varies, and often a runaway phase of the reaction is observed. Because such fires could be used for demonstrating the efficiency of a ventilation system, the power release must be controlled. This may have an important impact on the design of a mechanical ventilation system or the fire resistance of the infrastructure. To control the released power of such a fire, it is important to have a good understanding of this diffusion flame influenced by the environment. Then, understanding the phenomena that occur in the fire region means characterizing: the radiative fraction, the thermal exchanges and the impact of the flow on the fire. Using the results obtain along several experimental campaigns, both confined and unconfined, that were achieved in INERIS concerning pool fire, the different physical parameters are discussed and confronted with theoretical one. This paper proposed a physical characterization that finally leads to a power control strategy for pool fir

Numerical analysis of smoke layer stability

International audienceThe EGSISTES project is a global reflection about risk and dangerous phenomena relative to underground infrastructures. One category of risk identified for such an infrastructure is the fire and its consequences in terms of temperature and smoke propagation. In some situations, smoke stratification is used to ensure safety of people located inside the tunnel. In such a case, it must be ensure that smoke stay stratified even in the case of an aerodynamic perturbation such as a jet fan or vehicles presence. Two ways enable the improvement of the understanding of smoke behaviour in underground infrastructure: experiments and numerical approach. Both strategies are used complementary during the project. Experiments are achieved in the INERIS fire gallery while two CFD codes, FDS and Phoenics, based on two different approaches for turbulence modelling, are used. The first step consists in a comparison between experimental and numerical results on a configuration given as a reference. This reference case was chosen as the backlayering smoke layer establishment and stability. The numerical objective was to reproduce the length and thickness of this layer. After having shown that both codes should predict with a quite good accuracy the backlayering length, those two codes are used to study the influence of perturbation on the stratification stability. This study shows firstly that a jet located upstream the backlayering smoke layer tends to modify the smoke layer front but influences slightly the smoke layer near the fire. Secondly, in case of the presence of vehicles downstream the fire in a congested tunnel, the stratification is not altered just above vehicles but can be altered downstream these obstacles

Enseigner en anglais dans les universités françaises: quels effets prévisibles ?

Comme la proposition de loi relative à l’attractivité universitaire de la France, l projet de loi d’orientation de l’Enseignement supérieur et de la Recherche propose de rompre avec le principe qui fait du français la langue de l’enseignement, des examens, des concours et des thèses. Ce principe est inscrit dans la loi de 1994, dite loi Toubon, et découle de l’article 2 de la Constitution selon lequel «La langue de la République est le français». Une partie des enseignements effectués dans le..

Développement et validation d'un modèle eulérien en vue de la simulation des jets de carburants dans les moteurs à combustion interne

L'objectif de ce travail est de développer un modèle diphasique eulérien permettant de mieux prédire les jets de carburant dans les moteurs à combustion interne, en particulier la zone dense près des injecteurs. En effet, les modèles lagrangiens utilisés traditionnellement ne sont valables que pour des écoulements dispersés à faible fraction volumique de liquide, ce qui est incompatible avec les technologies moteurs actuelles utilisant une injection directe de carburant dans la chambre de combustion. Plusieurs approches eulériennes sont disponibles dans la littérature. Les phénomènes physiques se déroulant près de l'injecteur et les caractéristiques de chacune des approches ont permis de retenir un modèle à deux fluides et deux pressions. La dérivation du modèle a fait apparaître de nombreux termes ouverts : échanges entre phases et correlations turbulentes. Des fermetures ont été proposées pour chacun de ces termes. La fermeture des termes d'échanges utilise l'hypothèse de gouttes sphériques, tandis qu'une approche RANS est adoptée pour la modélisation des phénomènes turbulents. Ce modèle a été implanté dans le code de calcul 3D de l'IFP, IFP-C3D. De nombreux tests numériques et de nombreuses validations analytiques (monophasiques et diphasiques) ont ensuite été réalisés afin de s'assurer de l'implantation correcte des équations et de la prédictivité du modèle et des fermetures adoptées. D'autre part, les modifications du modèle de turbulence dans la phase gazeuse ont nécessité des validations supplémentaires aussi bien dans le gaz (écoulement derrière une marche) que dans le liquide (jet cylindrique) avant une validation du modèle complet sur une couche de mélange diphasique. Enfin, des tests d'injection ont été réalisés dans des conditions similaires à celles des moteurs dans l'objectif de s'assurer de la faisabilité des calculs moteurs à l'aide de l'approche eulérienne développée d'une part, et de la compatibilité du modèle avec le calcul moteur (prise en compte de mouvement de parois : piston, soupapes) d'autre part

Développement et validation d'un modèle eulérien en vue de la simulation des jets de carburants dans les moteurs à combustion interne

L'objectif de ce travail est de développer un modèle diphasique eulérien permettant de mieux prédire les jets de carburant dans les moteurs à combustion interne, en particulier la zone dense près des injecteurs. En effet, les modèles lagrangiens utilisés traditionnellement ne sont valables que pour des écoulements dispersés à faible fraction volumique de liquide, ce qui est incompatible avec les technologies moteurs actuelles utilisant une injection directe de carburant dans la chambre de combustion. Plusieurs approches eulériennes sont disponibles dans la littérature. Les phénomènes physiques se déroulant près de l'injecteur et les caractéristiques de chacune des approches ont permis de retenir un modèle à deux fluides et deux pressions. La dérivation du modèle a fait apparaître de nombreux termes ouverts : échanges entre phases et correlations turbulentes. Des fermetures ont été proposées pour chacun de ces termes. La fermeture des termes d'échanges utilise l'hypothèse de gouttes sphériques, tandis qu'une approche RANS est adoptée pour la modélisation des phénomènes turbulents. Ce modèle a été implanté dans le code de calcul 3D de l'IFP, IFP-C3D. De nombreux tests numériques et de nombreuses validations analytiques (monophasiques et diphasiques) ont ensuite été réalisés afin de s'assurer de l'implantation correcte des équations et de la prédictivité du modèle et des fermetures adoptées. D'autre part, les modifications du modèle de turbulence dans la phase gazeuse ont nécessité des validations supplémentaires aussi bien dans le gaz (écoulement derrière une marche) que dans le liquide (jet cylindrique) avant une validation du modèle complet sur une couche de mélange diphasique. Enfin, des tests d'injection ont été réalisés dans des conditions similaires à celles des moteurs dans l'objectif de s'assurer de la faisabilité des calculs moteurs à l'aide de l'approche eulérienne développée d'une part, et de la compatibilité du modèle avec le calcul moteur (prise en compte de mouvement de parois : piston, soupapes) d'autre part. ABSTRACT : The objective of this work is to develop an eulerian two phase model to improve the prediction of fuel injection in internal combustion engines, particularly the dense liquid zone close to the nozzle. Lagrangian models, usually used in engine simulations, are based on the assumption of dispersed two phase flows with low liquid volume fraction, which is not fulfilled in the case of direct injection engine technology. Different eulerian approaches are available in the literature. Physical phenomena that occur near the nozzle and characteristics of each model lead to the choice of a two fluids two pressures model. Several open terms appear in the equations of the model : exchange between the two phases and turbulent correlations. Closures of exchange terms are based on the spherical droplets hypothesis while a RANS approach is adopted to close turbulent correlations. This model has been integrated in the IFP CFD code, IFP-C3D. Several numerical tests and analytical validations (for single and two phase flows) have been then carried out in order to check the correct implementation of equations and the predictivity of the model and closures. Modifications in the turbulent model of the gas have required validations in both the gas phase (flow behind a sudden enlargement) and the liquid phase (pure liquid injection). A two phase mixing layer has been then used to validate the whole model. Finally, injection tests have been achieved under realistic conditions (similar to those encountered in automotive engines) in order to check the feasibility of engine computations using the developed eulerian approach. These tests have also allowed to check the compatibility of this approach with the specificities of engine simulations (especially mesh movement)

PORTFOLIO MANAGEMENT OF INNOVATION FIELDS : APPLYING CK DESIGN THEORY IN CROSS INDUSTRY EXPLORATORY PARTNERSHIP

International audienceOur paper refers to an industrial practice based on an integrated theoretical framework of design, CK design theory (Hatchuel and Weil, 2002, Hatchuel and Weil, 2003, Hatchuel and Weil, 2008), to support people in management of innovation fields. This study is based on an empirical case in a new form of R&D partnerships, the Cross Industry Exploratory Partnerships. MINATEC IDEAs Laboratory® is composed of a broad scope of partners 2 which aims to co-explore opportunities of micronanotechnologies. The paper deals with a strategic design tool, OPERA, which has been experimented since 2007 and involved participation of design team work and powerholders. During two years, creative insights and projects of the two laboratory's major innovation fields have been collected and structured within CK theory. This tool permits power-holders to drive innovation projects by giving an overview of explored concepts (and still not explored), activation and production of competencies and knowledge

Comparison of the fire consequences of an electric vehicle and an internal combustion engine vehicle

International audienceSince energy storage systems represent key new technologies in the development of electric vehicles (EV), risks pertaining to them have to be examined closely. Lithium-ion (Li-ion) batteries powering EV contain highly energetic active materials and flammable organic electrolytes, which raise safety questions, different to conventional cars. In case of EV fire, concerns remain about batteries fire behavior, about their impact on the fire growth, about their fire-induced potential toxicity, especially in confined spaces and underground car parks and about their reaction with water in case of firemen intervention. Fire tests were therefore achieved for two French car manufacturers on two battery units, on a full battery pack, on an EV and on an analogous internal combustion engine (ICE) vehicle. Thermal and toxic threat parameters governing the fire risk were quantified. For this purpose, the heat release rate and the effective heat of combustion were determined to qualify the thermal impact whereas the main emitted gases governing the toxic potency of the fire effluents were measured. Fire consequences of an EV and the corresponding ICE vehicle were compared. This paper aims at presenting the main results of these fire tests

Andrée et le GEPE

Per trent’anni, fin dalla sua creazione negli anni ’90, Andrée non ha mai smesso di portare prima il suo sostegno, poi la sua piena partecipazione al GEPE (Gruppo di studio sul plurilinguismo europeo), gruppo di ricerca dell’Università di Strasburgo. Collaborando attivamente alle sue manifestazioni (seminari, giornate di studio, commissioni di tesi o di abilitazioni alla ricerca), nonostante i suoi numerosi impegni, è sempre stata umanamente curiosa nei confronti dei ricercatori alle prime armi o confermati che vi ha potuto incontrare.For thirty years, since the start of the 1990s, Andrée followed and then fully took part in the GEPE (Groupe d’études sur le plurilinguisme européen), research team at Strasbourg University. As an active member participating in all its manifestations (seminars, workshops, conferences, PhD juries ; despite her busy agenda, she was always interested in and supportive of all our senior or junior research scholars