Project acronym 20SComplexity
Project An integrative approach to uncover the multilevel regulation of 20S proteasome degradation
Researcher (PI) Michal Sharon
Host Institution (HI) WEIZMANN INSTITUTE OF SCIENCE
Call Details Starting Grant (StG), LS1, ERC-2014-STG
Summary For many years, the ubiquitin-26S proteasome degradation pathway was considered the primary route for proteasomal degradation. However, it is now becoming clear that proteins can also be targeted for degradation by a ubiquitin-independent mechanism mediated by the core 20S proteasome itself. Although initially believed to be limited to rare exceptions, degradation by the 20S proteasome is now understood to have a wide range of substrates, many of which are key regulatory proteins. Despite its importance, little is known about the mechanisms that control 20S proteasomal degradation, unlike the extensive knowledge acquired over the years concerning degradation by the 26S proteasome. Our overall aim is to reveal the multiple regulatory levels that coordinate the 20S proteasome degradation route.
To achieve this goal we will carry out a comprehensive research program characterizing three distinct levels of 20S proteasome regulation:
Intra-molecular regulation- Revealing the intrinsic molecular switch that activates the latent 20S proteasome.
Inter-molecular regulation- Identifying novel proteins that bind the 20S proteasome to regulate its activity and characterizing their mechanism of function.
Cellular regulatory networks- Unraveling the cellular cues and multiple pathways that influence 20S proteasome activity using a novel systematic and unbiased screening approach.
Our experimental strategy involves the combination of biochemical approaches with native mass spectrometry, cross-linking and fluorescence measurements, complemented by cell biology analyses and high-throughput screening. Such a multidisciplinary approach, integrating in vitro and in vivo findings, will likely provide the much needed knowledge on the 20S proteasome degradation route. When completed, we anticipate that this work will be part of a new paradigm – no longer perceiving the 20S proteasome mediated degradation as a simple and passive event but rather a tightly regulated and coordinated process.
Summary
For many years, the ubiquitin-26S proteasome degradation pathway was considered the primary route for proteasomal degradation. However, it is now becoming clear that proteins can also be targeted for degradation by a ubiquitin-independent mechanism mediated by the core 20S proteasome itself. Although initially believed to be limited to rare exceptions, degradation by the 20S proteasome is now understood to have a wide range of substrates, many of which are key regulatory proteins. Despite its importance, little is known about the mechanisms that control 20S proteasomal degradation, unlike the extensive knowledge acquired over the years concerning degradation by the 26S proteasome. Our overall aim is to reveal the multiple regulatory levels that coordinate the 20S proteasome degradation route.
To achieve this goal we will carry out a comprehensive research program characterizing three distinct levels of 20S proteasome regulation:
Intra-molecular regulation- Revealing the intrinsic molecular switch that activates the latent 20S proteasome.
Inter-molecular regulation- Identifying novel proteins that bind the 20S proteasome to regulate its activity and characterizing their mechanism of function.
Cellular regulatory networks- Unraveling the cellular cues and multiple pathways that influence 20S proteasome activity using a novel systematic and unbiased screening approach.
Our experimental strategy involves the combination of biochemical approaches with native mass spectrometry, cross-linking and fluorescence measurements, complemented by cell biology analyses and high-throughput screening. Such a multidisciplinary approach, integrating in vitro and in vivo findings, will likely provide the much needed knowledge on the 20S proteasome degradation route. When completed, we anticipate that this work will be part of a new paradigm – no longer perceiving the 20S proteasome mediated degradation as a simple and passive event but rather a tightly regulated and coordinated process.
Max ERC Funding
1 500 000 €
Duration
Start date: 2015-04-01, End date: 2020-03-31
Project acronym 2D-4-CO2
Project DESIGNING 2D NANOSHEETS FOR CO2 REDUCTION AND INTEGRATION INTO vdW HETEROSTRUCTURES FOR ARTIFICIAL PHOTOSYNTHESIS
Researcher (PI) Damien VOIRY
Host Institution (HI) CENTRE NATIONAL DE LA RECHERCHE SCIENTIFIQUE CNRS
Call Details Starting Grant (StG), PE8, ERC-2018-STG
Summary CO2 reduction reaction (CO2RR) holds great promise for conversion of the green-house gas carbon dioxide into chemical fuels. The absence of catalytic materials demonstrating high performance and high selectivity currently hampers practical demonstration. CO2RR is also limited by the low solubility of CO2 in the electrolyte solution and therefore electrocatalytic reactions in gas phase using gas diffusion electrodes would be preferred. 2D materials have recently emerged as a novel class of electrocatalytic materials thanks to their rich structures and electronic properties. The synthesis of novel 2D catalysts and their implementation into photocatalytic systems would be a major step towards the development of devices for storing solar energy in the form of chemical fuels. With 2D-4-CO2, I propose to: 1) develop novel class of CO2RR catalysts based on conducting 2D nanosheets and 2) demonstrate photocatalytic conversion of CO2 into chemical fuels using structure engineered gas diffusion electrodes made of 2D conducting catalysts. To reach this goal, the first objective of 2D-4-CO2 is to provide guidelines for the development of novel cutting-edge 2D catalysts towards CO2 conversion into chemical fuel. This will be possible by using a multidisciplinary approach based on 2D materials engineering, advanced methods of characterization and novel designs of gas diffusion electrodes for the reduction of CO2 in gas phase. The second objective is to develop practical photocatalytic systems using van der Waals (vdW) heterostructures for the efficient conversion of CO2 into chemical fuels. vdW heterostructures will consist in rational designs of 2D materials and 2D-like materials deposited by atomic layer deposition in order to achieve highly efficient light conversion and prolonged stability. This project will not only enable a deeper understanding of the CO2RR but it will also provide practical strategies for large-scale application of CO2RR for solar fuel production.
Summary
CO2 reduction reaction (CO2RR) holds great promise for conversion of the green-house gas carbon dioxide into chemical fuels. The absence of catalytic materials demonstrating high performance and high selectivity currently hampers practical demonstration. CO2RR is also limited by the low solubility of CO2 in the electrolyte solution and therefore electrocatalytic reactions in gas phase using gas diffusion electrodes would be preferred. 2D materials have recently emerged as a novel class of electrocatalytic materials thanks to their rich structures and electronic properties. The synthesis of novel 2D catalysts and their implementation into photocatalytic systems would be a major step towards the development of devices for storing solar energy in the form of chemical fuels. With 2D-4-CO2, I propose to: 1) develop novel class of CO2RR catalysts based on conducting 2D nanosheets and 2) demonstrate photocatalytic conversion of CO2 into chemical fuels using structure engineered gas diffusion electrodes made of 2D conducting catalysts. To reach this goal, the first objective of 2D-4-CO2 is to provide guidelines for the development of novel cutting-edge 2D catalysts towards CO2 conversion into chemical fuel. This will be possible by using a multidisciplinary approach based on 2D materials engineering, advanced methods of characterization and novel designs of gas diffusion electrodes for the reduction of CO2 in gas phase. The second objective is to develop practical photocatalytic systems using van der Waals (vdW) heterostructures for the efficient conversion of CO2 into chemical fuels. vdW heterostructures will consist in rational designs of 2D materials and 2D-like materials deposited by atomic layer deposition in order to achieve highly efficient light conversion and prolonged stability. This project will not only enable a deeper understanding of the CO2RR but it will also provide practical strategies for large-scale application of CO2RR for solar fuel production.
Max ERC Funding
1 499 931 €
Duration
Start date: 2019-01-01, End date: 2023-12-31
Project acronym 2G-CSAFE
Project Combustion of Sustainable Alternative Fuels for Engines used in aeronautics and automotives
Researcher (PI) Philippe Dagaut
Host Institution (HI) CENTRE NATIONAL DE LA RECHERCHE SCIENTIFIQUE CNRS
Call Details Advanced Grant (AdG), PE8, ERC-2011-ADG_20110209
Summary This project aims at promoting sustainable combustion technologies for transport via validation of advanced combustion kinetic models obtained using sophisticated new laboratory experiments, engines, and theoretical computations, breaking through the current frontier of knowledge. It will focus on the unexplored kinetics of ignition and combustion of 2nd generation (2G) biofuels and blends with conventional fuels, which should provide energy safety and sustainability to Europe. The motivation is that no accurate kinetic models are available for the ignition, oxidation and combustion of 2G-biofuels, and improved ignition control is needed for new compression ignition engines. Crucial information is missing: data from well characterised experiments on combustion-generated pollutants and data on key-intermediates for fuels ignition in new engines.
To provide that knowledge new well-instrumented complementary experiments and kinetic modelling will be used. Measurements of key-intermediates, stables species, and pollutants will be performed. New ignition control strategies will be designed, opening new technological horizons. Kinetic modelling will be used for rationalising the results. Due to the complexity of 2G-biofuels and their unusual composition, innovative surrogates will be designed. Kinetic models for surrogate fuels will be generalised for extension to other compounds. The experimental results, together with ab-initio and detailed modelling, will serve to characterise the kinetics of ignition, combustion, and pollutants formation of fuels including 2G biofuels, and provide relevant data and models.
This research is risky because this is (i) the 1st effort to measure radicals by reactor/CRDS coupling, (ii) the 1st effort to use a μ-channel reactor to build ignition databases for conventional and bio-fuels, (iii) the 1st effort to design and use controlled generation and injection of reactive species to control ignition/combustion in compression ignition engines
Summary
This project aims at promoting sustainable combustion technologies for transport via validation of advanced combustion kinetic models obtained using sophisticated new laboratory experiments, engines, and theoretical computations, breaking through the current frontier of knowledge. It will focus on the unexplored kinetics of ignition and combustion of 2nd generation (2G) biofuels and blends with conventional fuels, which should provide energy safety and sustainability to Europe. The motivation is that no accurate kinetic models are available for the ignition, oxidation and combustion of 2G-biofuels, and improved ignition control is needed for new compression ignition engines. Crucial information is missing: data from well characterised experiments on combustion-generated pollutants and data on key-intermediates for fuels ignition in new engines.
To provide that knowledge new well-instrumented complementary experiments and kinetic modelling will be used. Measurements of key-intermediates, stables species, and pollutants will be performed. New ignition control strategies will be designed, opening new technological horizons. Kinetic modelling will be used for rationalising the results. Due to the complexity of 2G-biofuels and their unusual composition, innovative surrogates will be designed. Kinetic models for surrogate fuels will be generalised for extension to other compounds. The experimental results, together with ab-initio and detailed modelling, will serve to characterise the kinetics of ignition, combustion, and pollutants formation of fuels including 2G biofuels, and provide relevant data and models.
This research is risky because this is (i) the 1st effort to measure radicals by reactor/CRDS coupling, (ii) the 1st effort to use a μ-channel reactor to build ignition databases for conventional and bio-fuels, (iii) the 1st effort to design and use controlled generation and injection of reactive species to control ignition/combustion in compression ignition engines
Max ERC Funding
2 498 450 €
Duration
Start date: 2011-12-01, End date: 2016-11-30
Project acronym AAA
Project Adaptive Actin Architectures
Researcher (PI) Laurent Blanchoin
Host Institution (HI) CENTRE NATIONAL DE LA RECHERCHE SCIENTIFIQUE CNRS
Call Details Advanced Grant (AdG), LS3, ERC-2016-ADG
Summary Although we have extensive knowledge of many important processes in cell biology, including information on many of the molecules involved and the physical interactions among them, we still do not understand most of the dynamical features that are the essence of living systems. This is particularly true for the actin cytoskeleton, a major component of the internal architecture of eukaryotic cells. In living cells, actin networks constantly assemble and disassemble filaments while maintaining an apparent stable structure, suggesting a perfect balance between the two processes. Such behaviors are called “dynamic steady states”. They confer upon actin networks a high degree of plasticity allowing them to adapt in response to external changes and enable cells to adjust to their environments. Despite their fundamental importance in the regulation of cell physiology, the basic mechanisms that control the coordinated dynamics of co-existing actin networks are poorly understood. In the AAA project, first, we will characterize the parameters that allow the coupling among co-existing actin networks at steady state. In vitro reconstituted systems will be used to control the actin nucleation patterns, the closed volume of the reaction chamber and the physical interaction of the networks. We hope to unravel the mechanism allowing the global coherence of a dynamic actin cytoskeleton. Second, we will use our unique capacity to perform dynamic micropatterning, to add or remove actin nucleation sites in real time, in order to investigate the ability of dynamic networks to adapt to changes and the role of coupled network dynamics in this emergent property. In this part, in vitro experiments will be complemented by the analysis of actin network remodeling in living cells. In the end, our project will provide a comprehensive understanding of how the adaptive response of the cytoskeleton derives from the complex interplay between its biochemical, structural and mechanical properties.
Summary
Although we have extensive knowledge of many important processes in cell biology, including information on many of the molecules involved and the physical interactions among them, we still do not understand most of the dynamical features that are the essence of living systems. This is particularly true for the actin cytoskeleton, a major component of the internal architecture of eukaryotic cells. In living cells, actin networks constantly assemble and disassemble filaments while maintaining an apparent stable structure, suggesting a perfect balance between the two processes. Such behaviors are called “dynamic steady states”. They confer upon actin networks a high degree of plasticity allowing them to adapt in response to external changes and enable cells to adjust to their environments. Despite their fundamental importance in the regulation of cell physiology, the basic mechanisms that control the coordinated dynamics of co-existing actin networks are poorly understood. In the AAA project, first, we will characterize the parameters that allow the coupling among co-existing actin networks at steady state. In vitro reconstituted systems will be used to control the actin nucleation patterns, the closed volume of the reaction chamber and the physical interaction of the networks. We hope to unravel the mechanism allowing the global coherence of a dynamic actin cytoskeleton. Second, we will use our unique capacity to perform dynamic micropatterning, to add or remove actin nucleation sites in real time, in order to investigate the ability of dynamic networks to adapt to changes and the role of coupled network dynamics in this emergent property. In this part, in vitro experiments will be complemented by the analysis of actin network remodeling in living cells. In the end, our project will provide a comprehensive understanding of how the adaptive response of the cytoskeleton derives from the complex interplay between its biochemical, structural and mechanical properties.
Max ERC Funding
2 349 898 €
Duration
Start date: 2017-09-01, End date: 2022-08-31
Project acronym AAMOT
Project Arithmetic of automorphic motives
Researcher (PI) Michael Harris
Host Institution (HI) INSTITUT DES HAUTES ETUDES SCIENTIFIQUES
Call Details Advanced Grant (AdG), PE1, ERC-2011-ADG_20110209
Summary The primary purpose of this project is to build on recent spectacular progress in the Langlands program to study the arithmetic properties of automorphic motives constructed in the cohomology of Shimura varieties. Because automorphic methods are available to study the L-functions of these motives, which include elliptic curves and certain families of Calabi-Yau varieties over totally real fields (possibly after base change), they represent the most accessible class of varieties for which one can hope to verify fundamental conjectures on special values of L-functions, including Deligne's conjecture and the Main Conjecture of Iwasawa theory. Immediate goals include the proof of irreducibility of automorphic Galois representations; the establishment of period relations for automorphic and potentially automorphic realizations of motives in the cohomology of distinct Shimura varieties; the construction of p-adic L-functions for these and related motives, notably adjoint and tensor product L-functions in p-adic families; and the geometrization of the p-adic and mod p Langlands program. All four goals, as well as the others mentioned in the body of the proposal, are interconnected; the final goal provides a bridge to related work in geometric representation theory, algebraic geometry, and mathematical physics.
Summary
The primary purpose of this project is to build on recent spectacular progress in the Langlands program to study the arithmetic properties of automorphic motives constructed in the cohomology of Shimura varieties. Because automorphic methods are available to study the L-functions of these motives, which include elliptic curves and certain families of Calabi-Yau varieties over totally real fields (possibly after base change), they represent the most accessible class of varieties for which one can hope to verify fundamental conjectures on special values of L-functions, including Deligne's conjecture and the Main Conjecture of Iwasawa theory. Immediate goals include the proof of irreducibility of automorphic Galois representations; the establishment of period relations for automorphic and potentially automorphic realizations of motives in the cohomology of distinct Shimura varieties; the construction of p-adic L-functions for these and related motives, notably adjoint and tensor product L-functions in p-adic families; and the geometrization of the p-adic and mod p Langlands program. All four goals, as well as the others mentioned in the body of the proposal, are interconnected; the final goal provides a bridge to related work in geometric representation theory, algebraic geometry, and mathematical physics.
Max ERC Funding
1 491 348 €
Duration
Start date: 2012-06-01, End date: 2018-05-31
Project acronym AArteMIS
Project Aneurysmal Arterial Mechanics: Into the Structure
Researcher (PI) Pierre Joseph Badel
Host Institution (HI) ASSOCIATION POUR LA RECHERCHE ET LE DEVELOPPEMENT DES METHODES ET PROCESSUS INDUSTRIELS
Call Details Starting Grant (StG), PE8, ERC-2014-STG
Summary The rupture of an Aortic Aneurysm (AA), which is often lethal, is a mechanical phenomenon that occurs when the wall stress state exceeds the local strength of the tissue. Our current understanding of arterial rupture mechanisms is poor, and the physics taking place at the microscopic scale in these collagenous structures remains an open area of research. Understanding, modelling, and quantifying the micro-mechanisms which drive the mechanical response of such tissue and locally trigger rupture represents the most challenging and promising pathway towards predictive diagnosis and personalized care of AA.
The PI's group was recently able to detect, in advance, at the macro-scale, rupture-prone areas in bulging arterial tissues. The next step is to get into the details of the arterial microstructure to elucidate the underlying mechanisms.
Through the achievements of AArteMIS, the local mechanical state of the fibrous microstructure of the tissue, especially close to its rupture state, will be quantitatively analyzed from multi-photon confocal microscopy and numerically reconstructed to establish quantitative micro-scale rupture criteria. AArteMIS will also address developing micro-macro models which are based on the collected quantitative data.
The entire project will be completed through collaboration with medical doctors and engineers, experts in all required fields for the success of AArteMIS.
AArteMIS is expected to open longed-for pathways for research in soft tissue mechanobiology which focuses on cell environment and to enable essential clinical applications for the quantitative assessment of AA rupture risk. It will significantly contribute to understanding fatal vascular events and improving cardiovascular treatments. It will provide a tremendous source of data and inspiration for subsequent applications and research by answering the most fundamental questions on AA rupture behaviour enabling ground-breaking clinical changes to take place.
Summary
The rupture of an Aortic Aneurysm (AA), which is often lethal, is a mechanical phenomenon that occurs when the wall stress state exceeds the local strength of the tissue. Our current understanding of arterial rupture mechanisms is poor, and the physics taking place at the microscopic scale in these collagenous structures remains an open area of research. Understanding, modelling, and quantifying the micro-mechanisms which drive the mechanical response of such tissue and locally trigger rupture represents the most challenging and promising pathway towards predictive diagnosis and personalized care of AA.
The PI's group was recently able to detect, in advance, at the macro-scale, rupture-prone areas in bulging arterial tissues. The next step is to get into the details of the arterial microstructure to elucidate the underlying mechanisms.
Through the achievements of AArteMIS, the local mechanical state of the fibrous microstructure of the tissue, especially close to its rupture state, will be quantitatively analyzed from multi-photon confocal microscopy and numerically reconstructed to establish quantitative micro-scale rupture criteria. AArteMIS will also address developing micro-macro models which are based on the collected quantitative data.
The entire project will be completed through collaboration with medical doctors and engineers, experts in all required fields for the success of AArteMIS.
AArteMIS is expected to open longed-for pathways for research in soft tissue mechanobiology which focuses on cell environment and to enable essential clinical applications for the quantitative assessment of AA rupture risk. It will significantly contribute to understanding fatal vascular events and improving cardiovascular treatments. It will provide a tremendous source of data and inspiration for subsequent applications and research by answering the most fundamental questions on AA rupture behaviour enabling ground-breaking clinical changes to take place.
Max ERC Funding
1 499 783 €
Duration
Start date: 2015-04-01, End date: 2020-03-31
Project acronym ABDESIGN
Project Computational design of novel protein function in antibodies
Researcher (PI) Sarel-Jacob Fleishman
Host Institution (HI) WEIZMANN INSTITUTE OF SCIENCE
Call Details Starting Grant (StG), LS1, ERC-2013-StG
Summary We propose to elucidate the structural design principles of naturally occurring antibody complementarity-determining regions (CDRs) and to computationally design novel antibody functions. Antibodies represent the most versatile known system for molecular recognition. Research has yielded many insights into antibody design principles and promising biotechnological and pharmaceutical applications. Still, our understanding of how CDRs encode specific loop conformations lags far behind our understanding of structure-function relationships in non-immunological scaffolds. Thus, design of antibodies from first principles has not been demonstrated. We propose a computational-experimental strategy to address this challenge. We will: (a) characterize the design principles and sequence elements that rigidify antibody CDRs. Natural antibody loops will be subjected to computational modeling, crystallography, and a combined in vitro evolution and deep-sequencing approach to isolate sequence features that rigidify loop backbones; (b) develop a novel computational-design strategy, which uses the >1000 solved structures of antibodies deposited in structure databases to realistically model CDRs and design them to recognize proteins that have not been co-crystallized with antibodies. For example, we will design novel antibodies targeting insulin, for which clinically useful diagnostics are needed. By accessing much larger sequence/structure spaces than are available to natural immune-system repertoires and experimental methods, computational antibody design could produce higher-specificity and higher-affinity binders, even to challenging targets; and (c) develop new strategies to program conformational change in CDRs, generating, e.g., the first allosteric antibodies. These will allow targeting, in principle, of any molecule, potentially revolutionizing how antibodies are generated for research and medicine, providing new insights on the design principles of protein functional sites.
Summary
We propose to elucidate the structural design principles of naturally occurring antibody complementarity-determining regions (CDRs) and to computationally design novel antibody functions. Antibodies represent the most versatile known system for molecular recognition. Research has yielded many insights into antibody design principles and promising biotechnological and pharmaceutical applications. Still, our understanding of how CDRs encode specific loop conformations lags far behind our understanding of structure-function relationships in non-immunological scaffolds. Thus, design of antibodies from first principles has not been demonstrated. We propose a computational-experimental strategy to address this challenge. We will: (a) characterize the design principles and sequence elements that rigidify antibody CDRs. Natural antibody loops will be subjected to computational modeling, crystallography, and a combined in vitro evolution and deep-sequencing approach to isolate sequence features that rigidify loop backbones; (b) develop a novel computational-design strategy, which uses the >1000 solved structures of antibodies deposited in structure databases to realistically model CDRs and design them to recognize proteins that have not been co-crystallized with antibodies. For example, we will design novel antibodies targeting insulin, for which clinically useful diagnostics are needed. By accessing much larger sequence/structure spaces than are available to natural immune-system repertoires and experimental methods, computational antibody design could produce higher-specificity and higher-affinity binders, even to challenging targets; and (c) develop new strategies to program conformational change in CDRs, generating, e.g., the first allosteric antibodies. These will allow targeting, in principle, of any molecule, potentially revolutionizing how antibodies are generated for research and medicine, providing new insights on the design principles of protein functional sites.
Max ERC Funding
1 499 930 €
Duration
Start date: 2013-09-01, End date: 2018-08-31
Project acronym ADDECCO
Project Adaptive Schemes for Deterministic and Stochastic Flow Problems
Researcher (PI) Remi Abgrall
Host Institution (HI) INSTITUT NATIONAL DE RECHERCHE ENINFORMATIQUE ET AUTOMATIQUE
Call Details Advanced Grant (AdG), PE1, ERC-2008-AdG
Summary The numerical simulation of complex compressible flow problem is still a challenge nowaday even for simple models. In our opinion, the most important hard points that need currently to be tackled and solved is how to obtain stable, scalable, very accurate, easy to code and to maintain schemes on complex geometries. The method should easily handle mesh refinement, even near the boundary where the most interesting engineering quantities have to be evaluated. Unsteady uncertainties in the model, for example in the geometry or the boundary conditions should represented efficiently.This proposal goal is to design, develop and evaluate solutions to each of the above problems. Our work program will lead to significant breakthroughs for flow simulations. More specifically, we propose to work on 3 connected problems: 1-A class of very high order numerical schemes able to easily deal with the geometry of boundaries and still can solve steep problems. The geometry is generally defined by CAD tools. The output is used to generate a mesh which is then used by the scheme. Hence, any mesh refinement process is disconnected from the CAD, a situation that prevents the spread of mesh adaptation techniques in industry! 2-A class of very high order numerical schemes which can utilize possibly solution dependant basis functions in order to lower the number of degrees of freedom, for example to compute accurately boundary layers with low resolutions. 3-A general non intrusive technique for handling uncertainties in order to deal with irregular probability density functions (pdf) and also to handle pdf that may evolve in time, for example thanks to an optimisation loop. The curse of dimensionality will be dealt thanks Harten's multiresolution method combined with sparse grid methods. Currently, and up to our knowledge, no scheme has each of these properties. This research program will have an impact on numerical schemes and industrial applications.
Summary
The numerical simulation of complex compressible flow problem is still a challenge nowaday even for simple models. In our opinion, the most important hard points that need currently to be tackled and solved is how to obtain stable, scalable, very accurate, easy to code and to maintain schemes on complex geometries. The method should easily handle mesh refinement, even near the boundary where the most interesting engineering quantities have to be evaluated. Unsteady uncertainties in the model, for example in the geometry or the boundary conditions should represented efficiently.This proposal goal is to design, develop and evaluate solutions to each of the above problems. Our work program will lead to significant breakthroughs for flow simulations. More specifically, we propose to work on 3 connected problems: 1-A class of very high order numerical schemes able to easily deal with the geometry of boundaries and still can solve steep problems. The geometry is generally defined by CAD tools. The output is used to generate a mesh which is then used by the scheme. Hence, any mesh refinement process is disconnected from the CAD, a situation that prevents the spread of mesh adaptation techniques in industry! 2-A class of very high order numerical schemes which can utilize possibly solution dependant basis functions in order to lower the number of degrees of freedom, for example to compute accurately boundary layers with low resolutions. 3-A general non intrusive technique for handling uncertainties in order to deal with irregular probability density functions (pdf) and also to handle pdf that may evolve in time, for example thanks to an optimisation loop. The curse of dimensionality will be dealt thanks Harten's multiresolution method combined with sparse grid methods. Currently, and up to our knowledge, no scheme has each of these properties. This research program will have an impact on numerical schemes and industrial applications.
Max ERC Funding
1 432 769 €
Duration
Start date: 2008-12-01, End date: 2013-11-30
Project acronym ADORA
Project Asymptotic approach to spatial and dynamical organizations
Researcher (PI) Benoit PERTHAME
Host Institution (HI) SORBONNE UNIVERSITE
Call Details Advanced Grant (AdG), PE1, ERC-2016-ADG
Summary The understanding of spatial, social and dynamical organization of large numbers of agents is presently a fundamental issue in modern science. ADORA focuses on problems motivated by biology because, more than anywhere else, access to precise and many data has opened the route to novel and complex biomathematical models. The problems we address are written in terms of nonlinear partial differential equations. The flux-limited Keller-Segel system, the integrate-and-fire Fokker-Planck equation, kinetic equations with internal state, nonlocal parabolic equations and constrained Hamilton-Jacobi equations are among examples of the equations under investigation.
The role of mathematics is not only to understand the analytical structure of these new problems, but it is also to explain the qualitative behavior of solutions and to quantify their properties. The challenge arises here because these goals should be achieved through a hierarchy of scales. Indeed, the problems under consideration share the common feature that the large scale behavior cannot be understood precisely without access to a hierarchy of finer scales, down to the individual behavior and sometimes its molecular determinants.
Major difficulties arise because the numerous scales present in these equations have to be discovered and singularities appear in the asymptotic process which yields deep compactness obstructions. Our vision is that the complexity inherent to models of biology can be enlightened by mathematical analysis and a classification of the possible asymptotic regimes.
However an enormous effort is needed to uncover the equations intimate mathematical structures, and bring them at the level of conceptual understanding they deserve being given the applications motivating these questions which range from medical science or neuroscience to cell biology.
Summary
The understanding of spatial, social and dynamical organization of large numbers of agents is presently a fundamental issue in modern science. ADORA focuses on problems motivated by biology because, more than anywhere else, access to precise and many data has opened the route to novel and complex biomathematical models. The problems we address are written in terms of nonlinear partial differential equations. The flux-limited Keller-Segel system, the integrate-and-fire Fokker-Planck equation, kinetic equations with internal state, nonlocal parabolic equations and constrained Hamilton-Jacobi equations are among examples of the equations under investigation.
The role of mathematics is not only to understand the analytical structure of these new problems, but it is also to explain the qualitative behavior of solutions and to quantify their properties. The challenge arises here because these goals should be achieved through a hierarchy of scales. Indeed, the problems under consideration share the common feature that the large scale behavior cannot be understood precisely without access to a hierarchy of finer scales, down to the individual behavior and sometimes its molecular determinants.
Major difficulties arise because the numerous scales present in these equations have to be discovered and singularities appear in the asymptotic process which yields deep compactness obstructions. Our vision is that the complexity inherent to models of biology can be enlightened by mathematical analysis and a classification of the possible asymptotic regimes.
However an enormous effort is needed to uncover the equations intimate mathematical structures, and bring them at the level of conceptual understanding they deserve being given the applications motivating these questions which range from medical science or neuroscience to cell biology.
Max ERC Funding
2 192 500 €
Duration
Start date: 2017-09-01, End date: 2022-08-31
Project acronym AEROFLEX
Project AEROelastic instabilities and control of FLEXible Structures
Researcher (PI) Olivier Pierre MARQUET
Host Institution (HI) OFFICE NATIONAL D'ETUDES ET DE RECHERCHES AEROSPATIALES
Call Details Starting Grant (StG), PE8, ERC-2014-STG
Summary Aeroelastic instabilities are at the origin of large deformations of structures and are limiting the capacities of products in various industrial branches such as aeronautics, marine industry, or wind electricity production. If suppressing aeroelastic instabilities is an ultimate goal, a paradigm shift in the technological development is to take advantage of these instabilities to achieve others objectives, as reducing the drag of these flexible structures. The ground-breaking challenges addressed in this project are to design fundamentally new theoretical methodologies for (i) describing mathematically aeroelastic instabilities, (ii) suppressing them and (iii) using them to reduce mean drag of structures at a low energetic cost. To that aim, two types of aeroelastic phenomena will be specifically studied: the flutter, which arises as a result of an unstable coupling instability between two stable dynamics, that of the structures and that the flow, and vortex-induced vibrations which appear when the fluid dynamics is unstable. An aeroelastic global stability analysis will be first developed and applied to problems of increasing complexity, starting from two-dimensional free-vibrating rigid structures and progressing towards three-dimensional free-deforming elastic structures. The control of these aeroelastic instabilities will be then addressed with two different objectives: their suppression or their use for flow control. A theoretical passive control methodology will be established for suppressing linear aeroelastic instabilities, and extended to high Reynolds number flows and experimental configurations. New perturbation methods for solving strongly nonlinear problems and adjoint-based control algorithm will allow to use these aeroelastic instabilities for drag reduction. This project will allow innovative control solutions to emerge, not only in flutter or vortex-induced vibrations problems, but also in a much broader class of fluid-structure problems.
Summary
Aeroelastic instabilities are at the origin of large deformations of structures and are limiting the capacities of products in various industrial branches such as aeronautics, marine industry, or wind electricity production. If suppressing aeroelastic instabilities is an ultimate goal, a paradigm shift in the technological development is to take advantage of these instabilities to achieve others objectives, as reducing the drag of these flexible structures. The ground-breaking challenges addressed in this project are to design fundamentally new theoretical methodologies for (i) describing mathematically aeroelastic instabilities, (ii) suppressing them and (iii) using them to reduce mean drag of structures at a low energetic cost. To that aim, two types of aeroelastic phenomena will be specifically studied: the flutter, which arises as a result of an unstable coupling instability between two stable dynamics, that of the structures and that the flow, and vortex-induced vibrations which appear when the fluid dynamics is unstable. An aeroelastic global stability analysis will be first developed and applied to problems of increasing complexity, starting from two-dimensional free-vibrating rigid structures and progressing towards three-dimensional free-deforming elastic structures. The control of these aeroelastic instabilities will be then addressed with two different objectives: their suppression or their use for flow control. A theoretical passive control methodology will be established for suppressing linear aeroelastic instabilities, and extended to high Reynolds number flows and experimental configurations. New perturbation methods for solving strongly nonlinear problems and adjoint-based control algorithm will allow to use these aeroelastic instabilities for drag reduction. This project will allow innovative control solutions to emerge, not only in flutter or vortex-induced vibrations problems, but also in a much broader class of fluid-structure problems.
Max ERC Funding
1 377 290 €
Duration
Start date: 2015-07-01, End date: 2020-06-30
