Reliability and durability are key considerations to successfully deploy Proton Exchange Membrane Fuel Cells (PEMFCs). Since the link between materials defects and performances at the scales of the Membrane Electrode Assembly (MEA) and the stack is now well documented, LOCALI shall provide information about the propagation of these defects to other materials or to other locations in the stack. LOCALI aims to improve the existing systems and will ultimately provide effective tools to control their mass-production, the quality of the stacks and their diagnosis for on-site maintenance (stationary) or for on-board (transportation) applications. To these goals, the study focuses on three main axes, developed for PEMFCs (but which can easily be implemented for E-PEM). Firstly, LOCALI will develop instrumentation dedicated to local current density measurement and local electrochemical impedance spectroscopy: well-instrumented segmented cells and magnetic fields measurement are the core competences to these goals. The second challenge of LOCALI is, by using tailored defective MEAs or thanks to specific operating conditions (flooding, reagent exhaustion, ...) to characterize how local and overall performances of the MEA are affected, and to identify the signatures of the various anomalies. Our target is to identify the source of the heterogeneities as well as to locate degraded areas inside a stack. Finally, LOCALI will enable to track, during ageing, how the initial and controlled defects do propagate upon operation. A particular attention will be paid on two points: (i) does a defect in the one material of the MEA (e.g. a hole in the PEM) influence the local degradation of its neighboring materials (e.g. the catalyst layer); (ii) does the defect propagate spatially, and if so, does it happen only at the MEA scale (e.g. from the inlet to the outlet regions) or at the stack scale (i.e. from the defective cell to its neighboring ones).

Plate-form(E)3 project: "Digital Platform for calculation and optimization of Energy Efficiency and Environmental at different scales for industry (Component / Process / Plant / Planning)" should contribute to the optimization of energy efficiency and environmental industry and territories, considering the thermal aspects but also materials and integrating the system dynamics. This project submitted to the ANR represents a first step of a global platform, following the group's reflections programmatic 8 "Industry and Agriculture" of the ANCRE. The vision of this group is summarized in this sentence from the report ANCRE "The proposed program responds to a triple need: to evaluate the flow of energy and matter, evaluate the contribution of an added improved component or improved technology energy efficiency of a process or plant, and finally have a repository shared between all stakeholders (academia, industry, communities, etc.). Plate-form(E)3 will be concretized in a numerical tool to help design and decision based on cost/benefit, the costs and benefits can be economic and/or environmental. This tool for researchers, engineers from industry, energy consultants, engineers, local authorities will assess the impact of new technologies on a large scale, and to propose an energy integration across the territory seeking potential interconnections between industries (Territory scale ), to optimize process efficiency (plant/process scale) and help the optimal design of new technologies (component level). The platform will be based on existing tools, with defined methodologies, software and platforms. For this objective, an analysis study will be made (Tasks 1 and 2). Development tools and the missing tools will be realized in the project to complete the gaps identified (Task 3). Taking into account the needs of users, close links will be through for example with industry and local authority (Task 2), as a part of the overall project. Today this partnership represents the "designers" of this tool but will be extended to users in the following steps. They will be consulted to ensure the adequacy of the platform and its functionality to their needs. We can already mention the following entities as being interested in participating in the overall construction of the platform: • industrials such as Lafarge, INEOS, Arcelor Mittal who want to reduce their energy and environmental impact, • communities like Grand Lyon who wishes to develop their territory at best in terms of energy and environmental, • engineering companies such as Technip using this tool that could take into account environmental plant energy before its amendment or its implementation. This ANR project partnership includes key stakeholders in the field in France and abroad. Methodological aspects and software for the process are investigated within the framework of the ANR project CERES-2 by EDF, Armines, and the LEMTA IFPEN. The partners cover the areas of energy efficiency technologies (EDF), optimization methodology and modeling efficiency (Armines and LEMTA), processes, technical-economic and environmental impact (IFPEN, INDEED). Building efficiency (Plant) reflects the activities of CETIAT. The developed tool aiming to be valued and must willing optimized high performance digital Federation Hermite Charles will bring his expertise on these topics.

The subject of this project is the 3D printing (SLS) of PA12/glass beads composite for applications in aerospace industry. The SLS process uses laser sintering of composite powder with polymer matrix containing glass beads. One of the limiting points of polymers composites for their use in aerospace systems is their durability, and more specifically their resistance to failure due to fatigue cracking. The objective of this project will focus on the study of finished products obtained by SLS of composites powders and their resistance to cracking. The objectives of this work are to understand failure mechanisms in these highly heterogeneous materials at two scales, the scale of the microsctructure and the scale of the workpiece, by combining experimental characterization of cracks networks by mechanical testing, 3D imaging by X-rays laboratory microtomography image analysis, and numerical simulations. The identified microstructural damage models will be used to construct a crack propagation model at the scale of the workpieces, and will account for specificities related to the material and the process: the highly heterogeneous nature of the microstructure and its strong anisotropy due to the layered structure obtained by SLS. Then, it will be used to optimize the process parameters and the shapes of products in the design step. Up to now, the damage mechanisms in compounds obtained by SLS 3D printing are not very well understood, even less for products obtained from composite powders. The objectives imply several challenges related to the numerical simulation of complex crack networks in highly heterogeneous materials, the detection of micro cracks by 3D imagery imaging within combined with in situ mechanical testing, the modelling of damage and its identification at both micro and macro scales. The mechanical parameters, including the damage ones, will be characterized at the micro and macro scales by approaches combining tomography within microstructures (damage at the interfaces, damage related to the layered structure of the material) or at the scale of the workpiece, and numerical simulations through inverse approaches. The studied material is obtained from composite powder made of a polymer matrix of PA12 and containing glass beads. The powder is then sintered by laser to obtain 3D workpieces by PRISMADD. This project will allow optimizing the process parameters of the 3D process and the geometries of the workpieces with respect to failure criteria and lightweight. A numerical simulation code working able to capture damage mechanisms at both microscopic and macroscopic scales will be developed, based on the phase field method. This technique allows modelling initiation, propagation and merging of complex 3D crack networks in heterogeneous media. The method will be extended to the behaviour related to the material, characterized by a strongly nonlinear anisotropic behaviour. The tasks will consist into: (a) developing an efficient modeling numerical framework for simulating complex networks of cracks in highly heterogeneous microstructures from voxel models such as those arising from X-rays computed micro tomography imaging (XRµCT) and at the scale of the workpieces; (b) manufacturing by SLS 3D printing samples for a set of controlled process parameters; (c) characterize the strength properties of the new manufactured materials, with both macroscopic experimental mechanical testing and imaging at microscale, based on in situ mechanical testing in imaging devices and full-field kinematic measurement techniques, in 2D (optical observation) and in full 3D (XRµCT) ; (d) proposing microstructural and macroscopic damage models, identifying them by the mentioned experiments, and developing simplified multiscale damage models for bridging micro and macro damage; (e) optimizing the process parameters and the geometries of the produced workpieces with respect to the strength resistance of the produced products.

This project falls within the framework of aviation security related to icing. Recent serious events related to icing with the presence of droplets with diameter between 50 microns and 1 millimetre lead to the modification of the regulation for aircraft certification. In order to deal with these new demands in terms of certification, we saw the emergence of European projects such as WEZARD or EXTICE in which new wind tunnel capabilities where developed in icing conditions. However, even if those capabilities are now fully operational, it is not certain that the reproduced icing conditions are fully controlled until specific parameters such as the supercooled droplets temperature or local hygrometry are checked and measured. Furthermore, it is necessary to check that the droplets are really over icing and to evaluate the presence of ice in the droplets. To date and to our knowledge, there is no reference experiment to deal with those three parameters. Thus, this project aims to develop, from existing techniques, new experimental diagnostics to measure supercooled droplets temperature, the fraction of ice within the droplet and the hydrometry with the presence of droplets, in icing aeronautical conditions. These conditions involve droplets having velocities up to about 250 m/s and diameter of several millimetres. Therefore, this ambitious project will be carry out via a partnership gathering together four labs (LEMTA from the Université de Lorraine, DGA Essais Propulseurs in Saclay, IRSTEA in Antony and CORIA in Rouen), each lab bringing its own expertise. Taking into account that icing aeronautical conditions are an extreme environment, this project is split in two work-packages. The first work-package is dedicated to the development of all the measurements techniques leading to characterize supercooled droplets having velocity and diameter of about 10 m/s and 300 µm respectively. The second work-package constitutes the main output of the project since the goal is to apply the previous improved measurements techniques under aeronautical conditions (velocity of about 150 m/s in maximum). In parallel, a transverse numerical activity will be undertaken in order to bring assistance for several expected steps in both work-packages. The first work-package is divided in three parts. The first one is devoted to the development of an experimental set-up (Experiment 1) to allow the generation of supercooled droplets at lower velocity (about10 m/s). For the second part, the experimental techniques for the measure of the droplet temperature, the fraction of ice within the droplet and the hygrometry will be set-up. The second work-package will be conducted also in two parts. In a first part, a small size dynamic wind tunnel will be developed (Experiment 2) to generate supercooled droplets at high speeds. Then, Experiment 2 will be used to undertake an experimental campaign in order to characterise the over melted droplets (temperature and ice fraction). On top of this, the project is also intending to provide a sufficient level of maturity for measurement techniques which could be used on one side for the normalisation work of the Society of Automotive Engineers (SAE) (Calibration methods for icing plants) and on the other side for a potential involvement in future European projects to complement EXTICE.

FRAISE project intends to optimize energy conversion through falling-film absorption processes. Its main technological outcome is the development of innovative concepts for the design of efficient desorbers, which represents the bottleneck for the conception of new compact absorption machines adapted to automotive air-conditioning, and more generally to the design of efficient heat pumps, chillers and recovery systems to limit energy waste. The project focuses on the automotive application for which compactness is crucial. Yet, the investigated design solutions will benefit to the development of compact absorption machines adapted to abundant low-grade temperature sources (industrial waste, marine transports) and renewable energies (solar cooling, domestic heating). Desorbers are key elements of the absorption machines where coupled heat and mass transfer occur. The correct sizing and the compactness of these components represent the principal challenges to the aimed technical application. We propose to develop new concepts of desorbers using plate exchangers with falling films, which have the advantage to be easily operated in vacuum conditions as required whenever low-temperature heat sources are considered. In this project, we propose to optimize and control the wavy motion of a falling film in order to intensify heat and mass transfers across the film. Indeed, it is known that the mixing and surface renewal mechanisms generated by surface waves may enhance heat and mass transfer rates several folds. This project is thus devoted to the wavy regime that mostly develops at moderate Reynolds numbers. Passive control by means of wall corrugations will be considered and tested under external vibrations. The design of new strategies of transfer intensification requires (i) to understand how the wavy dynamics is affected by the coupling with the transfer due to the induced variations of physical properties at the free surface, (ii) to identify the most efficient wavy structures and their optimum dynamics (rates of creation and merging, spatial and temporal distribution etc.) to promote transfers and (iii) to propose efficient strategies to control the hydrodynamics of the flow, generate these wavy structures and their distribution in time and space and to test these strategies under external vibrations. To meet such requirements, we propose a strategy combining an advanced fundamental research effort and a latter-stage more applied study with the adaptation of a dedicated prototype of absorption machine and a test campaign on an experimental bench developed by the industrial partner. This exploratory project, oriented to fundamental research combine theoretical and numerical approaches based on direct numerical simulations (DNS), advanced shallow-water mathematical modelling and thermodynamic modelling at the component and system levels, to experimental studies using avant-garde non-intrusive optical techniques, and in particular, a two-colour Laser-Induced Fluorescence technique that will be adapted to to measure in-depth temperature gradient across the wavy film. The project will take advantage of the skills of three complementary laboratories in the field of Heat/Mass Transfer using specific non-intrusive optical techniques (LEMTA), Applied Mathematics and shallow-water approaches (LAMA/LOCIE) and Engineering with the design of absorption machines (LOCIE). The projects benefits from the involvement of the industrial partner (PSA) (two already financed test benches, one of which at PSA). The synergy between the theoretical and experimental investigations will be fostered by the proximity between two partners (LOCIE and LAMA on the same campus) and the regular meetings of the informal CNRS group GDR FILMS.