The research team is interested in modelling the entire energy chain, from production to consumption, including distribution and supervision. Understanding the precise physical functioning of production machines allows us to rationalise their use and use them for storage. An essential numerical part completes the work by proposing models of energy distribution networks and communication systems necessary for the optimisation of the whole.
Based on all engineering fields, innovative materials and structures are experiencing considerable growth. This involves the development of new technologies, including additive manufacturing and intelligent materials. The research team participates in this field of research by focusing on three subjects: multi-scale modelling of materials; improvement of additive manufacturing processes and characterisation of the performance of new materials.
Complex fluid modelling concerns all fluids that cannot be described by the Navier-Stokes equations. Most of the problems studied are related to complex fluid dynamics and multiphase flows, in particular fluid-particle interactions. The research developed involves interdisciplinary collaboration between several scientific fields. We propose a mathematical and numerical analysis of these fluids with industrial applications.
The professors and researchers of the Modeling Group
Publications of the professors and researchers of the Modeling Group
Fortin, André; Yakoubi, Driss
A very high order discontinuous Galerkin method for the numerical solution of stiff DDEs Journal Article
In: Applied Mathematics And Computation, vol. 443, no. 1, pp. 1-15, 2023.
@article{fortin_2076,
title = {A very high order discontinuous Galerkin method for the numerical solution of stiff DDEs},
author = {André Fortin and Driss Yakoubi},
url = {https://www.sciencedirect.com/science/article/pii/S0096300322008359},
year = {2023},
date = {2023-04-01},
journal = {Applied Mathematics And Computation},
volume = {443},
number = {1},
pages = {1-15},
abstract = {We present a high order discontinuous Galerkin (DG) method for the numerical solution of systems of delay differential equations (DDEs). The method is based on Legendre orthogonal polynomials of high degree k (typically k=10) in each subinterval and is a generalisation to DDEs of a similar method which proved to be very efficient for ordinary differential equations (ODEs). We show how the error can be estimated allowing to control the size of the time step. We also propose a particularly efficient quasi Newton method for the solution of the resulting non linear systems based on a very accurate approximation of the Jacobian matrix that is very easy to implement and with excellent convergence properties. The method is then applied to very stiff systems of DDEs.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Taleb, Ihab; Guérard, Guillaume; Fauberteau, Frédéric; Nguyen, Nga
A holonic multi-agent architecture for smart grids Inproceedings
In: International Conference on Agents and Artificial Intelligence, Lisbon, Portugal, 2023, ISBN: 978-989-758-547-0.
@inproceedings{taleb_2073,
title = {A holonic multi-agent architecture for smart grids},
author = {Ihab Taleb and Guillaume Guérard and Frédéric Fauberteau and Nga Nguyen},
url = {https://icaart.scitevents.org/},
issn = {978-989-758-547-0},
year = {2023},
date = {2023-02-01},
booktitle = {International Conference on Agents and Artificial Intelligence},
address = {Lisbon, Portugal},
abstract = {The global warming and the increase of fossil fuel prices make the minimization of energy generation an important objective. Thus, smart grids are becoming more and more relevant in a context where we want to regulate the demand according to the available energy. This regulation can be operated thanks to Demand Side Management (DSM) tools. While different models and architectures have been developed for smart grids, only few papers used holonic architectures. For this, we propose in this paper a holonic architecture for smart grids. This type of architectures is relevant to smart grids as it allow the various actors in the grids to work even in the cases of technical problems. Holons in the proposed model are composed of five interconnecting agents that ensure flexibility on the various aspects. This model has been tested and has proven to work on 3 different scenarios. The first scenario simulates a grid in its healthy state. The second one simulates a grid where a region can be disconnected from a blackout for example. The third one simulates a grid with production mismanagement. Results show how the grid distributes the available energy depending on the available production, priorities (if any) and the assurance of the distribution across the various requesting holons.},
keywords = {},
pubstate = {published},
tppubtype = {inproceedings}
}
Chami, Nada; Salehy, Yasmine; Burgner, Dennis; Clain, Pascal; Dalmazzone, Didier; Delahaye, Anthony; Fournaison, Laurence
Rheological study of mixed cyclopentane + CO2 hydrate slurry in a dynamic loop for refrigeration systems Journal Article
In: Energy, vol. 263, pp. 125661, 2023.
@article{chami_1961,
title = {Rheological study of mixed cyclopentane + CO2 hydrate slurry in a dynamic loop for refrigeration systems},
author = {Nada Chami and Yasmine Salehy and Dennis Burgner and Pascal Clain and Didier Dalmazzone and Anthony Delahaye and Laurence Fournaison},
url = {https://www.sciencedirect.com/science/article/pii/S0360544222025476},
year = {2023},
date = {2023-01-01},
journal = {Energy},
volume = {263},
pages = {125661},
abstract = {The use of CO2 hydrates as phase change materials is promising for secondary loop refrigeration, as these compounds present adjustable dissociation temperature that can be higher than 273.15 K and have high enthalpy of dissociation. In the present work, by using various promoters, cyclopentane (CP) in this study, the formation pressure of hydrates may be significantly lowered than CO2 hydrates. For their application as a secondary refrigerant, the rheological properties of mixed CP + CO2 hydrate slurry need to be controlled. The flow properties of CP and mixed CP + CO2 hydrate slurries were studied in a dynamic flow loop at different cyclopentane contents ranging from 3 wt% to 15 wt%, using a capillary viscometer based on Rabinowitch and Mooney equation. Rheological parameters (viscosity, flow behavior...) related to these two slurries were compared. The experimental results demonstrate that CP and mixed CP + CO2 hydrates slurries exhibit a shear thinning behavior and the viscosity values vary between 3 and 12 mPa.s-1 at [100-1000 s?1] for CP hydrates slurries and between 2 and 10 mPa s?1 at [100-1200 s?1] for CP + CO2 hydrates slurries. CP hydrate and CP + CO2 hydrate slurry viscosity is close to that of TBPB hydrate and lower than that of CO2 hydrate. Moreover, mixed CP + CO2 have shown a time-evolution of the rheological behavior.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Samah, Walid; Clain, Pascal; Rioual, François; Fournaison, Laurence; Delahaye, Anthony
Experimental investigation on the wetting behavior of a superhydrophobic surface under controlled temperature and humidity Journal Article
In: vol. 656, pp. 130451, 2023.
@article{samah_2025,
title = {Experimental investigation on the wetting behavior of a superhydrophobic surface under controlled temperature and humidity},
author = {Walid Samah and Pascal Clain and François Rioual and Laurence Fournaison and Anthony Delahaye},
url = {https://www.sciencedirect.com/science/article/pii/S0927775722022063},
year = {2023},
date = {2023-01-01},
volume = {656},
pages = {130451},
abstract = {Superhydrophobic surfaces (SHS) are of great interest in various industrial fields. However, the application of these surfaces in cold, humid and submerged environments (as in the case of ice slurry production) sometimes presents problems related to the loss of their superhydrophobic properties. This paper presents an experimental study in order to characterize the wetting behavior of a surface coated with a commercial superhydrophobic "Ultra Ever Dry" (UED) coating at different surface temperatures (from 22 °C to ? 13 °C) and relative humidity (13%, 20%, 30%, 40% and 50%). Three methods are developed to characterize the wetting behavior. The first method consists in depositing a water drop on the cooled superhydrophobic UED surface. The objective is to characterize the static wetting behavior (evolution of contact angles) during the cooling of the surface for different relative humidity. The second method consists in dropping a water drop on the cooled UED superhydrophobic surface with an impact velocity of 1 m s?1. This method allows the dynamic behavior of the wetting (impact and rebound of the drop) to be characterized at different temperatures. The third method, consists in studying the effect of the immersion of the SHS in a volume of water cooled until supercooling then freezing. The aim is to analyze the wetting behavior in immersion at low temperature. The results of the static wetting study show that the superhydrophobic coating loses its non-wetting properties at temperatures below 13 °C for a relative humidity between 13% and 50% due to condensation on the surface. The results of the dynamic wetting study show that the superhydrophobic coating has poor resistance to water drop impact at surface temperatures below 4 °C. The wetting transition from Cassie to Wenzel state in low temperature immersion is caused by ice formation. The wettability state influences the morphology of the ice produced after freezing.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Samah, Walid; Clain, Pascal; Rioual, François; Fournaison, Laurence; Delahaye, Anthony
Review on ice crystallization and adhesion to optimize ice slurry generators without moving components Journal Article
In: Applied Thermal Engineering, vol. 223, 2023.
@article{samah_2080,
title = {Review on ice crystallization and adhesion to optimize ice slurry generators without moving components},
author = {Walid Samah and Pascal Clain and François Rioual and Laurence Fournaison and Anthony Delahaye},
url = {https://www-sciencedirect-com.devinci.idm.oclc.org/science/article/pii/S1359431123000030},
year = {2023},
date = {2023-01-01},
journal = {Applied Thermal Engineering},
volume = {223},
abstract = {The current climate crisis requires a radical reduction in energy consumption and greenhouse gas emissions. For the refrigeration industry, secondary refrigeration is one of the most accessible solutions to reduce the use of refrigerants with high greenhouse gas content. In addition, the use of low environmental impact two-phase secondary fluids, namely PCM (phase change material) slurries, such as ice slurries and gas hydrate slurries, can limit the electrical energy consumption involved in the process. Currently, the industry's most commonly used ice slurry production systems are scraped surface and supercooling generators. These have some disadvantages, such as maintenance costs and energy consumption. An ice slurry generator is considered efficient if it meets three criteria: continuous production, low energy consumption and reliable operation. Optimizing ice slurry production with generators without moving components (scraped surface) could be a solution to meet these criteria. The objective of this review is to present a critical analysis of ice slurry production optimization methods proposed in the literature. These methods aim either to prevent ice nucleation to produce supercooled water with a high supercooling degree, or to reduce the adhesion of the ice to the generator walls to facilitate its removal by flow or by external forces (gravity and buoyancy).},
keywords = {},
pubstate = {online},
tppubtype = {article}
}
Chami, Nada; Salehy, Yasmine; Clain, Pascal; Dalmazzone, Didier; Delahaye, Anthony; Fournaison, Laurence
Thermal and energy evaluation of mixed CP+CO2 hydrate slurries Conference
5ème Journées annuelles Hydrates, GDR2026, Hydrates de gaz IFPEN, Rueil-Malmaison, France, 2022.
@conference{chami_1910,
title = {Thermal and energy evaluation of mixed CP+CO2 hydrate slurries},
author = {Nada Chami and Yasmine Salehy and Pascal Clain and Didier Dalmazzone and Anthony Delahaye and Laurence Fournaison},
year = {2022},
date = {2022-12-01},
booktitle = {5ème Journées annuelles Hydrates},
address = {IFPEN, Rueil-Malmaison, France},
organization = {GDR2026, Hydrates de gaz},
abstract = {A thermal and energy study of mixed CP + CO2 hydrate slurries is presented to determine the hydrate fraction formed in the loop and to quantify the energy restituted by the mixed hydrate.
The work performed on mixed CP + CO2 hydrate slurries required the establishment of an experimental continuous circulation loop. A heat exchanger is connected to the loop to ensure the hydrates dissociation in order to determine the heat amount involved during the phase change. Thermal studies were also performed to determine the heat exchange coefficients.},
keywords = {},
pubstate = {accepted},
tppubtype = {conference}
}
Osswald, Véronique; Clain, Pascal; Dalmazzone, Didier; Chami, Nada; Salehy, Yasmine; Delahaye, Anthony; Fournaison, Laurence
Kinetic study of CO2 hydrates crystallization in stirred tank reactor based on heat balance Conference
5ème Journées annuelles Hydrates, GDR2026, Hydrates de gaz IFPEN, Rueil-Malmaison, France, 2022.
@conference{osswald_1911,
title = {Kinetic study of CO2 hydrates crystallization in stirred tank reactor based on heat balance},
author = {Véronique Osswald and Pascal Clain and Didier Dalmazzone and Nada Chami and Yasmine Salehy and Anthony Delahaye and Laurence Fournaison},
year = {2022},
date = {2022-12-01},
booktitle = {5ème Journées annuelles Hydrates},
address = {IFPEN, Rueil-Malmaison, France},
organization = {GDR2026, Hydrates de gaz},
abstract = {CO2 hydrate crystallization kinetics monitoring performs traditionally by a reactor mass balance. However, this method requires assumptions on CO2 liquid phase concentration and the number of hydration. This work presents the development of a specific method and device to determine the kinetics through direct measurement of the heat flow through the reactor shell and its evaluation compared with the mass balance method. The kinetic effect of two parameters (stirring speed, stirrer type) is outlined.},
keywords = {},
pubstate = {accepted},
tppubtype = {conference}
}
Salehy, Yasmine; Clain, Pascal; Chami, Nada; Osswald, Véronique; Delahaye, Anthony; Fournaison, Laurence
Rheological analysis of CO2 hydrate slurries in the presence of different additives Conference
5ème Journées annuelles Hydrates, GDR2026, Hydrates de gaz IFPEN, Rueil-Malmaison, France, 2022.
@conference{salehy_1912,
title = {Rheological analysis of CO2 hydrate slurries in the presence of different additives},
author = {Yasmine Salehy and Pascal Clain and Nada Chami and Véronique Osswald and Anthony Delahaye and Laurence Fournaison},
year = {2022},
date = {2022-12-01},
booktitle = {5ème Journées annuelles Hydrates},
address = {IFPEN, Rueil-Malmaison, France},
organization = {GDR2026, Hydrates de gaz},
abstract = {The rheological properties of OC2 hydrate slurries in the presence of additives are analyzed. The investigations are based on the capillary viscometer method and the experimental studies are conducted in a controled dynamic flow loop allowing to measure the pressure drop and flow rate. Then, the Hershel-Buckley model is used to determine the behavioral properties of the slurries. Finally, a discussion on the assumptions and limitations of this approach is proposed.},
keywords = {},
pubstate = {accepted},
tppubtype = {conference}
}
Vanaei, Hamidreza; Magri, Anouar El; Rastak, Mohammadali; Vanaei, Saeedeh; Vaudreuil, Sébastien; Tcharkhtchi, Abbas
Numerical-Experimental Analysis toward the Strain Rate Sensitivity of 3D-Printed Nylon Reinforced by Short Carbon Fiber Journal Article
In: Materials, vol. 15, no. 24, pp. 8722, 2022.
@article{vanaei_2061,
title = {Numerical-Experimental Analysis toward the Strain Rate Sensitivity of 3D-Printed Nylon Reinforced by Short Carbon Fiber},
author = {Hamidreza Vanaei and Anouar El Magri and Mohammadali Rastak and Saeedeh Vanaei and Sébastien Vaudreuil and Abbas Tcharkhtchi},
url = {https://doi.org/10.3390/ma15248722},
year = {2022},
date = {2022-12-01},
journal = {Materials},
volume = {15},
number = {24},
pages = {8722},
abstract = {Despite the application of the Additive Manufacturing process and the ability of parts' construction directly from a 3D model, particular attention should be taken into account to improve their mechanical characteristics. In this paper, we present the effect of individual process variables and the strain-rate sensitivity of Onyx (Nylon mixed with chopped carbon fiber) manufactured by Fused Filament Fabrication (FFF), using both experimental and simulation manners. The main objective of this paper is to present the effect of the selected printing parameters (print speed and platform temperature) and the sensitivity of the 3D-printed specimen to the strain rate during tensile behavior. A strong variation of tensile behavior for each set of conditions has been observed during the quasi-static tensile test. The variation of 40 °C in the platform temperature results in a 10% and 11% increase in Young's modulus and tensile strength, and 8% decrease in the failure strain, respectively. The variation of 20 mm·s?1 in print speed results in a 14% increase in the tensile strength and 11% decrease in the failure strain. The individual effect of process variables is inevitable and affects the mechanical behavior of the 3D-printed composite, as observed from the SEM micrographs (ductile to brittle fracture). The best condition according to their tensile behavior was chosen to investigate the strain rate sensitivity of the printed specimens both experimentally and using Finite Element (FE) simulations. As observed, the strain rate clearly affects the failure mechanism and the predicted behavior using the FE simulation. Increase in the elongation speed from 1 mm·min?1 to 100 mm·min?1, results in a considerable increase in Young's modulus. SEM micrographs demonstrated that although the mechanical behavior of the material varied by increasing the strain rate, the failure mechanism altered from ductile to brittle failure.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Vaudreuil, Sébastien; Bencaid, Salah Eddine; Vanaei, Hamidreza; Magri, Anouar El
Effects of Power and Laser Speed on the Mechanical Properties of AlSi7Mg0.6 Manufactured by Laser Powder Bed Fusion Journal Article
In: Materials, vol. 15, no. 23, pp. 8640, 2022.
@article{vaudreuil_2062,
title = {Effects of Power and Laser Speed on the Mechanical Properties of AlSi7Mg0.6 Manufactured by Laser Powder Bed Fusion},
author = {Sébastien Vaudreuil and Salah Eddine Bencaid and Hamidreza Vanaei and Anouar El Magri},
url = {https://doi.org/10.3390/ma15238640},
year = {2022},
date = {2022-12-01},
journal = {Materials},
volume = {15},
number = {23},
pages = {8640},
abstract = {The AlSi7Mg0.6 alloy, with its good tolerance against strain, is used in laser powder bed fusion (LPBF) to produce parts with complex geometries for aerospace engineering. Production of parts with good mechanical strength requires, however, the optimization of laser parameters. This study thus evaluated the influence of scanning speed, laser power, and strategy on several mechanical properties (tensile/resilience/hardness) to identify an optimal processing region. Results have shown the profound influence of laser power and scanning speed on mechanical properties, with a limited influence from the laser strategy. Tensile strength values ranging from 122 to 394 MPa were obtained, while Young's Modulus varied from 17 to 29 GPa, and the elongation at break ranged from 2.1 to 9.8%. Surface plots of each property against laser power and speed revealed a region of higher mechanical properties. This region is found when using 50 µm thick layers for energy densities between 25 and 35 J/mm3. Operating at higher values of energy density yielded sub-optimal properties, while a lower energy density resulted in poor performances. Results have shown that any optimization strategy must not only account for the volumic energy density value, but also for laser power itself when thick layers are used for fabrication. This was shown through parts exhibiting reduced mechanical performances that were produced within the optimal energy density range, but at low laser power. By combining mid-speed and power within the optimal region, parts with good microstructure and limited defects such as balling, keyhole pores, and hot cracking will be produced. Heat-treating AlSi7Mg0.6 parts to T6 temper negatively affected mechanical performances. Adapted tempering conditions are thus required if improvements are sought through tempering.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Arreola, Fernanda; Clain, Pascal
Quantum startup: using an analogy for theory development in the study of breakthrough innovation. Inproceedings
In: OMT - IAE Business School PDW, Organization & Management Theory Academy of Management, Derqui, Province of Buenos Aires, Argentina, 2022.
@inproceedings{arreola_1913,
title = {Quantum startup: using an analogy for theory development in the study of breakthrough innovation.},
author = {Fernanda Arreola and Pascal Clain},
year = {2022},
date = {2022-11-01},
booktitle = {OMT - IAE Business School PDW},
publisher = {Academy of Management},
address = {Derqui, Province of Buenos Aires, Argentina},
organization = {Organization & Management Theory},
keywords = {},
pubstate = {accepted},
tppubtype = {inproceedings}
}
Ouassil, Salah-Eddine Ouassil; Magri, Anouar El; Vanaei, Hamidreza; Vaudreuil, Sébastien
In: Journal Of Applied Polymer Science, vol. Not assigned yet, no. e53353, pp. 53353, 2022.
@article{ouassil_2046,
title = {Investigating the effect of printing conditions and annealing on the porosity and tensile behavior of 3D-printed polyetherimide material in Z-direction},
author = {Salah-Eddine Ouassil Ouassil and Anouar El Magri and Hamidreza Vanaei and Sébastien Vaudreuil},
url = {https://doi.org/10.1002/app.53353},
year = {2022},
date = {2022-11-01},
journal = {Journal Of Applied Polymer Science},
volume = {Not assigned yet},
number = {e53353},
pages = {53353},
abstract = {Fused filament fabrication process presents drawbacks in mechanical properties observed when printing in the build direction (Z-direction). Such anisotropic properties will affect the part's performances and have to be minimized during fabrication. This study aims to evaluate the effects of nozzle temperature, printing speed and specimen state (annealed or as-printed) on porosity percentage and tensile properties for 3D printed polyetherimide (PEI) (ULTEM 1010) parts in Z-direction. The results demonstrated that print speed is the most influential process parameter that should be adjusted in consideration with the other printing parameters. The specimens' state did not reveal a noticeable influence, as the amorphous nature of PEI is considered less receptive to annealing. The optimization method to achieve the best results yielded values of 360 °C and 30 mm/s as printing conditions, followed by heat treatment. This was confirmed by porosity measurements, tensile testing, and scanning electron microscopy observations. The best performances of PEI material were 3425.5 MPa, 102 MPa, and 4.30% for Young's modulus, tensile strength, and elongation at break, respectively.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Venkateswaran, Swaminath; Chablat, Damien Charles
Stability analysis of tensegrity mechanism coupled with a bio- inspired piping inspection robot Conference
47ème congrès de la Société de Biomécanique, Monastir, Tunisie, 2022.
@conference{venkateswaran_1843,
title = {Stability analysis of tensegrity mechanism coupled with a bio- inspired piping inspection robot},
author = {Swaminath Venkateswaran and Damien Charles Chablat},
url = {https://arxiv.org/ftp/arxiv/papers/2206/2206.01433.pdf},
year = {2022},
date = {2022-10-01},
booktitle = {47ème congrès de la Société de Biomécanique},
address = {Monastir, Tunisie},
abstract = {Piping inspection robots play an essential role for industries as they can reduce human effort and pose a lesser risk to their lives. Generally, the locomotion techniques of these robots can be classified into mechanical and bioinspired. By using slot-follower leg mechanisms, DC-motors, and control units, a rigid caterpillar type inspection robot was designed and developed at LS2N, France. This rigid prototype helped in identifying the static forces required to
accomplish good contact forces with the pipeline walls. In order to work inside curvatures, a tensegrity mechanism that uses three tension springs and a passive universal joint was introduced between each module of this robot. The optimal parameters of the robot assembly were identified by considering a preload of the cables, which ensured the stability of the entire robot. However, under static conditions, there exist some forces on the robot,
especially on the tensegrity mechanism when one end of the leg mechanism is clamped with the pipeline walls. These forces are dominant when the orientation of the pipeline is horizontal. The objective of this article is to understand the effect of the stiffness of
the spring on the static stability of the tensegrity mechanism under the self-weight of the robot assembly.},
keywords = {},
pubstate = {accepted},
tppubtype = {conference}
}
Benmesbah, Fatima; Clain, Pascal; Fandino, Olivia; Osswald, Véronique; Fournaison, Laurence; Dicharry, Christophe; Delahaye, Anthony
Calorimetric study of carbon dioxide (CO2) hydrate formation and dissociation processes in porous media Journal Article
In: Chemical Engineering Science, vol. 264, pp. 118108, 2022.
@article{benmesbah_1960,
title = {Calorimetric study of carbon dioxide (CO2) hydrate formation and dissociation processes in porous media},
author = {Fatima Benmesbah and Pascal Clain and Olivia Fandino and Véronique Osswald and Laurence Fournaison and Christophe Dicharry and Anthony Delahaye},
url = {https://www.sciencedirect.com/science/article/pii/S0009250922006923},
year = {2022},
date = {2022-10-01},
journal = {Chemical Engineering Science},
volume = {264},
pages = {118108},
abstract = {Understanding the formation and dissociation mechanisms of gas hydrate in porous media is important for the development of new energy-efficient and environmentally friendly technologies related to cold storage as they provide significant latent heat and energy density at suitable phase change temperature. The challenge is to understand the interactions between gas hydrates and the chosen storage media in order to assess the operating conditions likely to optimize time and energy consumption in cold production and storage systems. In this work, CO2 hydrates formation and dissociation are investigated in two morphologically different porous materials: sand and silica gels. A calorimetric approach is applied to study both the CO2 hydrate formation kinetics, particularly the induction time, and the amount of hydrate formed for each of the two porous materials. The experiments are performed using a differential thermal analysis device with two identical measuring cells. The present work is focused on assessing the effect of key factors like water saturation, particle size and the morphology of porous media on CO2 hydrate formation and dissociation processes. Overall, the results do not show a statistically significant correlation between these factors and the induction time. Interestingly, the results obtained with dual porous silica gel showed a higher amount of hydrate formed compared to those with sand for similar initial pressure, temperature and water content conditions. This result may be due to the fact that silica gels provide higher surface area due to their smaller particle size (20-45 µm vs 80-450 µm for sand), and the presence of internal pore volume in silica gel particles.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Vanaei, Hamidreza; Khelladi, Sofiane; Tcharkhtchi, Abbas
Roadmap: Numerical-Experimental Investigation and Optimization of 3D-Printed Parts Using Response Surface Methodology Journal Article
In: Materials, vol. 15, no. 20, pp. 7193, 2022.
@article{vanaei_1962,
title = {Roadmap: Numerical-Experimental Investigation and Optimization of 3D-Printed Parts Using Response Surface Methodology},
author = {Hamidreza Vanaei and Sofiane Khelladi and Abbas Tcharkhtchi},
url = {https://www.mdpi.com/1996-1944/15/20/7193},
year = {2022},
date = {2022-10-01},
journal = {Materials},
volume = {15},
number = {20},
pages = {7193},
abstract = {Several process variables can be taken into account to optimize the fused filament fabrication (FFF) process, a promising additive manufacturing technique. To take into account the most important variables, a numerical-experimental roadmap toward the optimization of the FFF process, by taking into account some physico-chemical and mechanical characteristics, has been proposed to implement the findings through the thermal behavior of materials. A response surface methodology (RSM) was used to consider the effect of liquefier temperature, platform temperature, and print speed. RSM gave a confidence domain with a high degree of crystallinity, Young's modulus, maximum tensile stress, and elongation at break. Applying the corresponding data from the extracted zone of optimization to the previously developed code showed that the interaction of parameters plays a vital role in the rheological characteristics, such as temperature profile of filaments during deposition. Favorable adhesion could be achieved through the deposited layers in the FFF process. The obtained findings nurture motivations for working on the challenges and bring us one step closer to the optimization objectives in the FFF process to solve the industrial challenges.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Magri, Anouar El; Bencaid, Salah Eddine; Vanaei, Hamidreza; Vaudreuil, Sébastien
Effects of Laser Power and Hatch Orientation on Final Properties of PA12 Parts Produced by Selective Laser Sintering Journal Article
In: Polymers, vol. 14, no. 17, pp. 3674, 2022.
@article{el_magri_1892,
title = {Effects of Laser Power and Hatch Orientation on Final Properties of PA12 Parts Produced by Selective Laser Sintering},
author = {Anouar El Magri and Salah Eddine Bencaid and Hamidreza Vanaei and Sébastien Vaudreuil},
url = {https://www.mdpi.com/2073-4360/14/17/3674},
year = {2022},
date = {2022-09-01},
journal = {Polymers},
volume = {14},
number = {17},
pages = {3674},
abstract = {Poly(dodecano-12-lactam) (commercially known as polyamide ?PA12?) is one of the most resourceful materials used in the selective laser sintering (SLS) process due to its chemical and physical properties. The present work examined the influence of two SLS parameters, namely, laser power and hatch orientation, on the tensile, structural, thermal, and morphological properties of the fabricated PA12 parts. The main objective was to evaluate the suitable laser power and hatching orientation with respect to obtaining better final properties. PA12 powders and SLS-printed parts were assessed through their particle size distributions, X-ray diffraction (XRD), Fourier Transform Infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), a scanning electron microscope (SEM), and their tensile properties. The results showed that the significant impact of the laser power while hatching is almost unnoticeable when using a high laser power. A more significant condition of the mechanical properties is the uniformity of the powder bed temperature. Optimum factor levels were achieved at 95% laser power and parallel/perpendicular hatching. Parts produced with the optimized SLS parameters were then subjected to an annealing treatment to induce a relaxation of the residual stress and to enhance the crystallinity. The results showed that annealing the SLS parts at 170 °C for 6 h significantly improved the thermal, structural, and tensile properties of 3D-printed PA12 parts},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Boudin, Laurent; Rossi, Alex; Salvarani, Francesco
A kinetic model of polyatomic gas with resonant collisions Journal Article
In: Ricerche Di Matematica, 2022.
@article{boudin_1894,
title = {A kinetic model of polyatomic gas with resonant collisions},
author = {Laurent Boudin and Alex Rossi and Francesco Salvarani},
url = {https://doi.org/10.1007/s11587-022-00733-1},
year = {2022},
date = {2022-09-01},
journal = {Ricerche Di Matematica},
keywords = {},
pubstate = {online},
tppubtype = {article}
}
Taleb, Ihab; Guérard, Guillaume; Fauberteau, Frédéric; Nguyen, Nga
A Holonic Smart Grid Model for Isolated Areas Conference
European Conference on Machine Learning and Principles and Practice of Knowledge Discovery in Databases, PhD Forum, Grenoble, France, 2022.
@conference{taleb_1934,
title = {A Holonic Smart Grid Model for Isolated Areas},
author = {Ihab Taleb and Guillaume Guérard and Frédéric Fauberteau and Nga Nguyen},
url = {https://2022.ecmlpkdd.org/index.php/phd-forum/},
year = {2022},
date = {2022-09-01},
booktitle = {European Conference on Machine Learning and Principles and Practice of Knowledge Discovery in Databases, PhD Forum},
address = {Grenoble, France},
abstract = {Since the beginning of the $21$st century, smart grid models are gaining more and more importance as they play a major role in the demand side management and the flexible integration of renewable energy sources. Indeed, diverse architectures and models have been proposed for smart grids. In this paper, we propose a model composed of two parts, the first part is to optimize, on a weekly scale, thermal generation, and energy storage while prioritizing renewable energy sources to minimize global costs and global warming effects. The second part consists of, having optimized production and storage, the negotiation between neighboring holons on the same level using evolutionary game theory, combined with simulated annealing and Q-learning approaches to ensure a back and forth between the various levels.},
keywords = {},
pubstate = {published},
tppubtype = {conference}
}
Magri, Anouar El; Vanaei, Hamidreza; Bencaid, Salah Eddine; Vaudreuil, Sébastien
Effects of Laser Power and Hatch Orientation on Final Properties of PA12 Parts Produced by Selective Laser Sintering Journal Article
In: Polymers, vol. 14, no. 17, pp. 3674, 2022.
@article{el_magri_1958,
title = {Effects of Laser Power and Hatch Orientation on Final Properties of PA12 Parts Produced by Selective Laser Sintering},
author = {Anouar El Magri and Hamidreza Vanaei and Salah Eddine Bencaid and Sébastien Vaudreuil},
url = {https://doi.org/10.3390/polym14173674},
year = {2022},
date = {2022-09-01},
journal = {Polymers},
volume = {14},
number = {17},
pages = {3674},
abstract = {Poly(dodecano-12-lactam) (commercially known as polyamide ?PA12?) is one of the most resourceful materials used in the selective laser sintering (SLS) process due to its chemical and physical properties. The present work examined the influence of two SLS parameters, namely, laser power and hatch orientation, on the tensile, structural, thermal, and morphological properties of the fabricated PA12 parts. The main objective was to evaluate the suitable laser power and hatching orientation with respect to obtaining better final properties. PA12 powders and SLS-printed parts were assessed through their particle size distributions, X-ray diffraction (XRD), Fourier Transform Infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), a scanning electron microscope (SEM), and their tensile properties. The results showed that the significant impact of the laser power while hatching is almost unnoticeable when using a high laser power. A more significant condition of the mechanical properties is the uniformity of the powder bed temperature. Optimum factor levels were achieved at 95% laser power and parallel/perpendicular hatching. Parts produced with the optimized SLS parameters were then subjected to an annealing treatment to induce a relaxation of the residual stress and to enhance the crystallinity. The results showed that annealing the SLS parts at 170 °C for 6 h significantly improved the thermal, structural, and tensile properties of 3D-printed PA12 parts.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Borsoni, Thomas; Boudin, Laurent; Salvarani, Francesco
Compactness property of the linearized Boltzmann operator for a polyatomic gas undergoing resonant collisions Journal Article
In: Journal Of Mathematical Analysis And Applications, vol. 517, no. 1, pp. 126579, 2022.
@article{borsoni_1875,
title = {Compactness property of the linearized Boltzmann operator for a polyatomic gas undergoing resonant collisions},
author = {Thomas Borsoni and Laurent Boudin and Francesco Salvarani},
url = {https://www.sciencedirect.com/science/article/pii/S0022247X22005935?via%3Dihub},
year = {2022},
date = {2022-08-01},
journal = {Journal Of Mathematical Analysis And Applications},
volume = {517},
number = {1},
pages = {126579},
abstract = {In this paper, we investigate a compactness property of the linearized Boltzmann operator in the context of a polyatomic gas whose molecules undergo resonant collisions. The peculiar structure of resonant collision rules allows to tensorize the problem into a velocity-related one, neighbouring the monatomic case, and an internal energy-related one. Our analysis is based on a specific treatment of the internal energy contributions. We also propose a geometric variant of Grad's proof of the same compactness property in the monatomic case.},
keywords = {},
pubstate = {accepted},
tppubtype = {article}
}
Salhi, Loubna; Seaid, Mohammed; Yakoubi, Driss
Well-posedness and numerical approximation of steady convection-diffusion-reaction problems in porous media Journal Article
In: Computers & Mathematics With Applications, vol. 124, pp. 129-148, 2022.
@article{salhi_1885,
title = {Well-posedness and numerical approximation of steady convection-diffusion-reaction problems in porous media},
author = {Loubna Salhi and Mohammed Seaid and Driss Yakoubi},
url = {https://www.sciencedirect.com/science/article/abs/pii/S0898122122003443},
year = {2022},
date = {2022-08-01},
journal = {Computers & Mathematics With Applications},
volume = {124},
pages = {129-148},
abstract = {We study a class of steady nonlinear convection-diffusion-reaction problems in porous media. The governing equations consist of coupling the Darcy equations for the pressure and velocity fields to two equations for the heat and mass transfer. The viscosity and diffusion coefficients are assumed to be nonlinear depending on the temperature and concentration of the medium. Well-posedness of the coupled problem is analyzed and existence along with uniqueness of the weak solution is investigatedbased on a fixed-point method. An iterative scheme for solving the associated fixed-point problem is proposed and its convergence is studied. Numerical experiments are presented for two examples of coupled convection-diffusion-reaction problems. Applications to radiative heat transfer and propagation of thermal fronts in porous media are also included in this study. The obtained results show good numerical convergence and validate the established theoretical estimates.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
El-Amrani, Mofdi; Salhi, Loubna; Seaid, Mohammed; Yakoubi, Driss
An iterative scheme for solving acoupled Darcy-convection-diffusion model Journal Article
In: Journal Of Mathematical Analysis And Applications, vol. 517, no. 2, pp. 1-24, 2022.
@article{el-amrani_1887,
title = {An iterative scheme for solving acoupled Darcy-convection-diffusion model},
author = {Mofdi El-Amrani and Loubna Salhi and Mohammed Seaid and Driss Yakoubi},
url = {https://www.sciencedirect.com/science/article/pii/S0022247X22006175},
year = {2022},
date = {2022-08-01},
journal = {Journal Of Mathematical Analysis And Applications},
volume = {517},
number = {2},
pages = {1-24},
abstract = {We present an iterative scheme for the numerical analysis of a class of coupled Darcy-convection-diffusion problems modelling flow and heat transfer in porous media. The governing equations consist of the Darcy equations for the flow coupled to a convection-diffusion equation for heat transfer with nonlinear viscosity and diffusion coefficient depending on the temperature. Existence and uniqueness of the weak solution for the considered problem are first analyzed using a fixed-point method and then convergence study of two iterative schemes for the fixed-point algorithm is presented. Two numerical examples are selected to validate the theoretical estimates and to demonstrate the performance of the proposed algorithm. The obtained results support our theoretical expectations for a good numerical convergence with the developed estimates.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Amirat, Youcef; Hamdache, Kamel; Shelukhin, Vladimir V.
Homogenization of MHD flows in porous media Journal Article
In: Journal Of Differential Equations, vol. 339, no. 339, pp. 90-133, 2022.
@article{amirat_1963,
title = {Homogenization of MHD flows in porous media},
author = {Youcef Amirat and Kamel Hamdache and Vladimir V. Shelukhin},
url = {https://doi.org/10.1016/j.jde.2022.08.014},
year = {2022},
date = {2022-08-01},
journal = {Journal Of Differential Equations},
volume = {339},
number = {339},
pages = {90-133},
abstract = {The paper is concerned with the homogenization of a nonlinear differential system describing the flow of an electrically conducting, incompressible and viscous Newtonian fluid through a periodic porous medium, in the presence of a magnetic field. We introduce a variational formulation of the differential system equipped with boundary conditions. We show the existence of a solution of the variational problem, and derive uniform estimates of the solutions depending on the characteristic parameters of the flow. Using the two-scale convergence method, we rigorously derive a two-scale equation for the two-scale current density, and a two-pressure Stokes system. We derive, in the case of constant magnetic permeability, an explicit relation expressing the macroscopic velocity as a function of the macroscopic Lorentz force, the pressure gradient, the external body force, and the macroscopic current density, via two permeability filtration ten- sors. When the magnetic field is absent, this relation reduces to the Darcy law.
© 2022 Elsevier Inc. All rights reserved.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Guérard, Guillaume; Bichet, Lucas; Amor, Sofiane Ben
Survey on Javascript Engines Fuzzers Inproceedings
In: Springer, (Ed.): The 6th International Symposium on Cyber Security, Cryptology and Machine Learning, Springer, Virtual Event, 2022.
@inproceedings{guerard_1861,
title = {Survey on Javascript Engines Fuzzers},
author = {Guillaume Guérard and Lucas Bichet and Sofiane Ben Amor},
editor = {Springer},
year = {2022},
date = {2022-07-01},
booktitle = {The 6th International Symposium on Cyber Security, Cryptology and Machine Learning},
publisher = {Springer},
address = {Virtual Event},
abstract = {The security of Web users is becoming a major issue today. Thus, Web browsers and more particularly the JavaScript engines that compose them are studied carefully to detect and promptly correct the vulnerabilities that they embed. This article presents the current state of research on vulnerabilities affecting JavaScript engines, starting from the current research context to the research tools used.},
keywords = {},
pubstate = {accepted},
tppubtype = {inproceedings}
}
Montiel, Antoine; Nguyen, Thuy; Rountree, Cindy; Geertsen, Valérie; Guenoun, Patrick; Bonamy, Daniel
Effect of architecture disorder on the elastic response of two-dimensional lattice materials Journal Article
In: Physical Review E, vol. 106, no. 1, pp. 015004, 2022.
@article{montiel_1922,
title = {Effect of architecture disorder on the elastic response of two-dimensional lattice materials},
author = {Antoine Montiel and Thuy Nguyen and Cindy Rountree and Valérie Geertsen and Patrick Guenoun and Daniel Bonamy},
url = {https://journals.aps.org/pre/abstract/10.1103/PhysRevE.106.015004?ft=1},
year = {2022},
date = {2022-07-01},
journal = {Physical Review E},
volume = {106},
number = {1},
pages = {015004},
abstract = {We examine how disordering joint position influences the linear elastic behavior of lattice materials via numerical simulations in two-dimensional beam networks. Three distinct initial crystalline geometries are selected as representative of mechanically isotropic materials with low connectivity, mechanically isotropic materials with high connectivity, and mechanically anisotropic materials with intermediate connectivity. Introducing disorder generates spatial fluctuations in the elasticity tensor at the local (joint) scale. Proper coarse-graining reveals a well-defined continuum-level scale elasticity tensor. Increasing disorder aids in making initially anisotropic materials more isotropic. The disorder impact on the material stiffness depends on the lattice connectivity: Increasing the disorder softens lattices with high connectivity and stiffens those with low connectivity, without modifying the scaling between elastic modulus and density (linear scaling for high connectivity and cubic scaling for low connectivity). Introducing disorder in lattices with intermediate fixed connectivity reveals both scaling: the linear scaling occurs for low density, the cubic one at high density, and the crossover density increases with disorder. Contrary to classical formulations, this work demonstrates that connectivity is not the sole parameter governing elastic modulus scaling. It offers a promising route to access novel mechanical properties in lattice materials via disordering the architectures.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Nguyen, Thuy; Bonamy, Daniel
Effect of atomic-scale solid discreetness in brittle fracture problem Conference
11th European Solid Mechanics Conference, Galway, Ireland, 2022.
@conference{nguyen_1923,
title = {Effect of atomic-scale solid discreetness in brittle fracture problem},
author = {Thuy Nguyen and Daniel Bonamy},
url = {https://www.esmc2022.org/},
year = {2022},
date = {2022-07-01},
booktitle = {11th European Solid Mechanics Conference},
address = {Galway, Ireland},
abstract = {Material's resistance-to-failure is quantified by two dependent material constants (one is proportional to the square of the other): fracture energy and fracture toughness. Predicting their values from the solid structure at the atomistic scale remains insolved, even in the simplest situation of an ideal brittle fracture. By examining numerically crack growth in electrical analogues of brittle crystals with modulated geometries, we shed a new light on this question. We find that the value of fracture energy cannot be deduced from Griffith's free surface energy, as is generally believed [1]. Rather, it finds its origin in the matching between the continuum-level scale displacement field of solid mechanics and the discrete nature of solids at the atomic scale. By making use of the generic asymptotic form, referred to as Williams's series expansion [2], taken by the displacement field near the crack tip, we find an analytical solution for this matching, and subsequently a way to predict quantitativly fracture toughness from the atomistic parameters [3]. We will discuss how to extend the analysis to genuine elastic (plane stress) crack problems and predict fracture toughness in 2D and 3D materials. This work sheds new perspectives on how resistance-to-faillure is selected; and hence, how it can be improved. As such, it may catalyze novel research toward new architectured materials of superior strcutural performance via microstructure patterning : tougher, more durable, lighter and/or combining other functionalities.},
keywords = {},
pubstate = {published},
tppubtype = {conference}
}
Levy, Loup-Noé; Bosom, Jérémie; Guérard, Guillaume; Amor, Sofiane Ben; Bui, Marc; Tran, Hai
DevOps Model Appproach for Monitoring Smart Energy Systems Journal Article
In: Energies, vol. 15, no. 15, pp. 5516, 2022.
@article{levy_1924,
title = {DevOps Model Appproach for Monitoring Smart Energy Systems},
author = {Loup-Noé Levy and Jérémie Bosom and Guillaume Guérard and Sofiane Ben Amor and Marc Bui and Hai Tran},
url = {https://www.mdpi.com/1996-1073/15/15/5516},
year = {2022},
date = {2022-07-01},
journal = {Energies},
volume = {15},
number = {15},
pages = {5516},
abstract = {Energy systems are often socio-technical complex systems that are facing new challenges regarding technological and environmental changes. Because of their complex nature, they cannot be approached solely through analytical modeling, hence the inefficiency of most classical modeling approaches. In this article, a Hybrid Approach based on both systemic and analytical modeling is presented and applied to a case study. From this novel approach, a model?the Multi-Institution Building Energy System?is presented. It allowed us to highlight and detail the need for greater governance of energy systems. The socio-technical solutions identified to answer the issues of governance (Accuracy, Reliability and Fairness) were DevOps methodology and the use of Distributed Microservices Architecture. Based on this framework, the design of a Decision Support System assuring and exploiting state-of-the-art scalable tools for data management and machine learning factories is described in this article. Moreover, we wish to set up the conceptual basis necessary for the design of a generic theoretical framework of optimization applicable to complex socio-technical systems in the context of the management of a shared resource.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Nohra, Perla; Rejeb, Helmi Ben; Venkateswaran, Swaminath
Impact of automation during innovative remanufacturing processes in circular economy Inproceedings
In: 28th IEEE ICE/ITMC & 31st IAMOT Conference IEEE, Nancy, France, 2022, ISBN: TBC.
@inproceedings{nohra_1814,
title = {Impact of automation during innovative remanufacturing processes in circular economy},
author = {Perla Nohra and Helmi Ben Rejeb and Swaminath Venkateswaran},
url = {TBC},
issn = {TBC},
year = {2022},
date = {2022-06-01},
booktitle = {28th IEEE ICE/ITMC & 31st IAMOT Conference IEEE},
address = {Nancy, France},
abstract = {With the increasing demand of raw materials nowadays, and the decrease in supplies, the industrial sector is suffering, while the environment and the society are also indirectly affected. The goal to reach a sustainable development imposes several studies on the economic, environmental and community level. The aim of this paper is to provide an overview of the existing literature on automating remanufacturing, and its impacts on the three pillars of sustainability. The outcomes of this study will reveal the impacts of remanufacturing on sustainability and will conceptualize the impact of using automation and cobots, which are among the key concepts in industry 4.0. The investigation that covers each part of the remanufacturing process will help in formalizing an approach about the automation of such processes and improve the remanufacturing sector towards a more sustainable industry.},
keywords = {},
pubstate = {accepted},
tppubtype = {inproceedings}
}
Guérard, Guillaume; Taleb, Ihab; Nguyen, Nga; Fauberteau, Frédéric
Modélisation Multi-Agent pour les Réseaux Energétique Insulaires Inproceedings
In: Journées Francophones sur les Systèmes Multi-Agents, Saint-Etienne, France, 2022.
@inproceedings{guerard_1831,
title = {Modélisation Multi-Agent pour les Réseaux Energétique Insulaires},
author = {Guillaume Guérard and Ihab Taleb and Nga Nguyen and Frédéric Fauberteau},
year = {2022},
date = {2022-06-01},
booktitle = {Journées Francophones sur les Systèmes Multi-Agents},
address = {Saint-Etienne, France},
keywords = {},
pubstate = {accepted},
tppubtype = {inproceedings}
}
Chami, Nada; Clain, Pascal; Osswald, Véronique; Delahaye, Anthony; Fournaison, Laurence; Dalmazzone, Didier; Salehy, Yasmine
Rheological and thermal study of mixed CP + CO2 hydrates for refrigeration applications Inproceedings
In: 1th European Conference on Gas Hydrates, Lyon, France, 2022.
@inproceedings{chami_1849,
title = {Rheological and thermal study of mixed CP + CO2 hydrates for refrigeration applications},
author = {Nada Chami and Pascal Clain and Véronique Osswald and Anthony Delahaye and Laurence Fournaison and Didier Dalmazzone and Yasmine Salehy},
url = {https://ecgh2022.sciencesconf.org/},
year = {2022},
date = {2022-06-01},
booktitle = {1th European Conference on Gas Hydrates},
address = {Lyon, France},
abstract = {The use of gas hydrates in secondary refrigeration can reduce cooling environmental impact by greenhouse gas reduction because of there high energy density. CO2 hydrates was selected at previous work as a candidate material for secondary refrigeration. In this study, cyclopentane, a thermodynamic promoter that has been identified for its promotive qualities to lower the formation pressure of CO2 hydrates was used to form mixed CP + CO2 hydrate slurries. This work deploys a temperature-controlled flowloop to characterize the rheological properties of hydrate slurries generated in situ from oil-in-water emulsions. Systems of 3 - 15wt% cyclopentane fraction to form pure CP hydrate and mixed CP + CO2 hydrate slurries were tested. The results showed that the viscosity of CP and mixed CP + CO2 hydrate slurries increase with the decrease of the shear rate, exhibiting a shear-thinning behavior. With a similar protocol, a rheological characterization involving a long period of hydrate slurries circulation was conducted. The results illustrated that the hydrate slurries behavior change with time. A thermal study was performed using heating tube method applied and heat transfer coefficients were determined for different cyclopentane fraction.},
keywords = {},
pubstate = {accepted},
tppubtype = {inproceedings}
}
Osswald, Véronique; Clain, Pascal; Dalmazzone, Didier; Delahaye, Anthony; Fournaison, Laurence
Experimental heat transfer measurement applied to CO2 hydrate formation kinetic study Inproceedings
In: 1th European Conference on Gas Hydrates, Lyon, France, 2022.
@inproceedings{osswald_1850,
title = {Experimental heat transfer measurement applied to CO2 hydrate formation kinetic study},
author = {Véronique Osswald and Pascal Clain and Didier Dalmazzone and Anthony Delahaye and Laurence Fournaison},
url = {https://ecgh2022.sciencesconf.org/},
year = {2022},
date = {2022-06-01},
booktitle = {1th European Conference on Gas Hydrates},
address = {Lyon, France},
abstract = {CO
2 hydrate slurry is a promising phase change material for secondary refrigeration cold distribution
issues, due to its high latent heat (about 500 kJ.kg 1 of water, higher than that of ice 333 kJ.kg 1) and
wide melting temperature range suitable for air c onditioning application. While the thermodynamic
properties of CO 2 hydrates are now well established, knowledge of crystallization kinetics phenomena
is still a challenge. Trying to understand and control the formation of gas hydrates is a key factor since
their discovery in pipeline plugs by Hammerschmidt, but unlike that case, the goal here is to promote
the rate of CO 2 hydrate formation. Most laboratory scale hydrate reactors are equipped with pressure
and temperature loggers, and mass balance on CO 2 all ows formation kinetic studies, but with
assumptions on CO 2 concentration in liquid phase in the liquid phase and the hydration number.
The
present work investigates the kinetics of CO 2 hydrate crystallization for different types of stirrers
and stirring sp eed conditions in a jacketed stirred batch reactor. Heat balance obtain experimentally
using a specially developed sensor installed on the cooling jacket. The mass fraction of crystallized
hydrate determine directly from the heat balance on the cooling jac ket. First, tests on water heating and
cooling steps and ice crystallization allowed the method validation before to apply it to CO 2 hydrate
crystallization. Experimental results described with an empirical model and compared to other mass
balance based ki netic determinations. Finally, the development of a simplified thermal model improved
this kinetic determination by estimating heat fl ows inside the reactor and with the environment.},
keywords = {},
pubstate = {accepted},
tppubtype = {inproceedings}
}
Osswald, Véronique; Clain, Pascal; Dalmazzone, Didier; Fournaison, Laurence; Delahaye, Anthony
Suivi cinétique de la cristallisation des hydrates de CO2 par mesure thermique - Effet de l'agitation Inproceedings
In: CRISTAL 10, Lyon, France, 2022.
@inproceedings{osswald_1851,
title = {Suivi cinétique de la cristallisation des hydrates de CO2 par mesure thermique - Effet de l'agitation},
author = {Véronique Osswald and Pascal Clain and Didier Dalmazzone and Laurence Fournaison and Anthony Delahaye},
url = {http://cristal10.univ-lyon1.fr/fr},
year = {2022},
date = {2022-06-01},
booktitle = {CRISTAL 10},
address = {Lyon, France},
abstract = {Les coulis d'hydrates de CO2 constituent un matériau à changement de phase prometteur pour la distribution du froid en réfrigération secondaire [1], en raison de leur chaleur latente élevée (environ 500 kJ.kg-1 d'eau, supérieure à celle de la glace: 333 kJ.kg-1) et de leur large plage de température de fusion adaptée aux applications de climatisation. Ce sont des structures cristallines proche de la glace, au sein desquelles sont enclathrées des molécules de dioxyde de carbone. Si les propriétés thermodynamiques des hydrates de CO2 sont désormais bien établies, la connaissance des phénomènes cinétiques de cristallisation reste parcellaire [2]. Comprendre et contrôler la formation des hydrates de gaz est un défi depuis leur découverte dans les bouchons de pipeline par Hammerschmidt [3]. Mais contrairement à ce cas, où l'on cherche à retarder l'apparition des hydrates, l'objectif ici est de favoriser leur cristallisation. La plupart des réacteurs dans lesquels est étudiée la cristallisation des hydrates à l'échelle du laboratoire sont équipés d'enregistreurs de pression et de température, et c'est à partir d'un bilan matière sur le CO2, en faisant des hypothèses sur la concentration de CO2 en phase liquide et le nombre d'hydratation, que le suivi de la cinétique est réalisé [4].
L'objet des travaux présentés ici est l'étude de la cinétique de cristallisation des hydrates de CO2 pour différents types d'agitateurs et différentes conditions de vitesse d'agitation dans un réacteur batch agité à double enveloppe. Le bilan thermique est obtenu expérimentalement en utilisant un capteur spécialement développé et installé sur la double enveloppe du réacteur. La fraction massique cristallisée est déterminée directement à partir du bilan thermique sur la double-enveloppe. Des essais sur les étapes de chauffage et de refroidissement de l'eau et la cristallisation de la glace ont permis de valider la méthode avant de l'appliquer à la cristallisation des hydrates de CO2. Les résultats expérimentaux sont décrits à partir d'un modèle empirique et comparés à d'autres déterminations cinétiques basées sur le bilan de matière. Enfin, le développement d'un modèle thermique simplifié du réacteur a permis d'améliorer cette détermination cinétique en estimant les flux de chaleur au sein du réacteur et avec l'environnement.},
keywords = {},
pubstate = {accepted},
tppubtype = {inproceedings}
}
Bobbia, Benjamin
Théorème de Donsker pour des mesures empiriques locales sur des régions aléatoires Conference
53-ème journées de statistique, Lyon, France, 2022.
@conference{bobbia_1855,
title = {Théorème de Donsker pour des mesures empiriques locales sur des régions aléatoires},
author = {Benjamin Bobbia},
year = {2022},
date = {2022-06-01},
booktitle = {53-ème journées de statistique},
address = {Lyon, France},
abstract = {Nowadays, empirical processes are well known objects. A reason that push forward theirs studies is that, in many models, we can write the estimators as images of empirical measures. In this work we investigate the case of local empirical measures built over a sub-sample with data conditioned to be in a certain area. There exists numerous results about such question, but what can we say if the area of interest is data driven ? In the present work we present a general framework which allows to derive asymptotic results for this particular empirical measures (with "low" cost in terms of technicality and assumptions). This approach is mainly presented through the prism of extreme values theory. And we present an example illustrating how this empirical conditional measure assumption work well with optimal transport methods.},
keywords = {},
pubstate = {accepted},
tppubtype = {conference}
}
Clain, Pascal; Fournaison, Laurence; Rioual, François; Delahaye, Anthony
In: 30ème congrès annuel de la Société Française de Thermique, Valenciennes, France, 2022.
@inproceedings{clain_1852,
title = {Étude du comportement de mouillage d'une goutte d'eau sur une surface superhydrophobe en fonction de la température et de l'humidité},
author = {Pascal Clain and Laurence Fournaison and François Rioual and Anthony Delahaye},
url = {http://www.congres-sft.fr/2022/},
year = {2022},
date = {2022-05-01},
booktitle = {30ème congrès annuel de la Société Française de Thermique},
address = {Valenciennes, France},
abstract = {Cet article présente une étude sur le comportement de mouillage d'une gouttes sur une
surface recouverte d'un revêtement superhydrophobe à différentes températures de surface et humidités
relatives. Les résultats montrent que l'évolution des angles de contact pendant le refroidissement des
surfaces est influencée par deux phénomènes : le premier est l'évaporation des gouttes et le second est
la condensation de la vapeur d'eau sur ces surfaces à basse température. Un modèle semi-empirique
de l'évaporation d'une goutte sur une surface superhydrophobe est présenté et comparé aux résultats
expérimentaux.},
keywords = {},
pubstate = {accepted},
tppubtype = {inproceedings}
}
Abdallah, Abir Ben; Kallel, Achraf; Tcharkhtchi, Abbas; Hassine, Tarek; Gamaoun, Fehmi
Modeling of viscoelastic behavior of a shape memory polymer blend Journal Article
In: Journal Of Applied Polymer Science, vol. 139, no. 13, pp. 51859, 2022.
@article{ben_abdallah_1721,
title = {Modeling of viscoelastic behavior of a shape memory polymer blend},
author = {Abir Ben Abdallah and Achraf Kallel and Abbas Tcharkhtchi and Tarek Hassine and Fehmi Gamaoun},
url = {https://onlinelibrary.wiley.com/doi/10.1002/app.51859},
year = {2022},
date = {2022-05-01},
journal = {Journal Of Applied Polymer Science},
volume = {139},
number = {13},
pages = {51859},
abstract = {Shape memory effect (SME) of polymers is a property that concerns both,
macroscopic and microscopic changes. The variation of internal polymer
properties such, as molecular weight (Mw), rigidity, and viscoelasticity could
alter its SME. In this study, a bi-parabolic model with six parameters is used to
describe the viscoelastic behavior of a shape memory polymer (SMP) blend
(40% poly(caprolactone), PCL/60% Styrene-Butadiene-Styrene) with different
PCL Mw. These parameters are determined using the Cole-Cole method.
Modeling curves (E00 = f (E0)) will be then compared to experimental data from
dynamical mechanical analysis (DMA) tests. It is shown that the bi-parabolic
model predicts well the behavior of the SMP mixture for different Mw of PCL.
Afterwards, the evolution of the model parameters with the Mw of PCL is
investigated. It is revealed that, when Mw of PCL drops, the relaxation modulus
E0 increases. This result proves that the rigidity of the SMP blend rises with
Mw declines.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Taleb, Ihab; Guérard, Guillaume; Nguyen, Nga; Fauberteau, Frédéric
A Flexible Deep Learning Method for Energy Forecasting Journal Article
In: Energies, vol. 15, no. 11, pp. 3926, 2022.
@article{taleb_1836,
title = {A Flexible Deep Learning Method for Energy Forecasting},
author = {Ihab Taleb and Guillaume Guérard and Nga Nguyen and Frédéric Fauberteau},
url = {https://www.mdpi.com/1996-1073/15/11/3926},
year = {2022},
date = {2022-05-01},
journal = {Energies},
volume = {15},
number = {11},
pages = {3926},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Samah, Walid; Clain, Pascal; Fournaison, Laurence; Rioual, François; Delahaye, Anthony
In: 30ème congrès annuel de la Société Française de Thermique, Valenciennes, France, 2022.
@inproceedings{samah_1852,
title = {Étude du comportement de mouillage d'une goutte d'eau sur une surface superhydrophobe en fonction de la température et de l'humidité},
author = {Walid Samah and Pascal Clain and Laurence Fournaison and François Rioual and Anthony Delahaye},
url = {http://www.congres-sft.fr/2022/},
year = {2022},
date = {2022-05-01},
booktitle = {30ème congrès annuel de la Société Française de Thermique},
address = {Valenciennes, France},
abstract = {Cet article présente une étude sur le comportement de mouillage d'une gouttes sur une
surface recouverte d'un revêtement superhydrophobe à différentes températures de surface et humidités
relatives. Les résultats montrent que l'évolution des angles de contact pendant le refroidissement des
surfaces est influencée par deux phénomènes : le premier est l'évaporation des gouttes et le second est
la condensation de la vapeur d'eau sur ces surfaces à basse température. Un modèle semi-empirique
de l'évaporation d'une goutte sur une surface superhydrophobe est présenté et comparé aux résultats
expérimentaux.},
keywords = {},
pubstate = {accepted},
tppubtype = {inproceedings}
}
Salvarani, Francesco
Exponential convergence towards consensus for non-symmetric linear first-order systems in finite and infinite dimensions Conference
Applied Analysis, Complex Systems & Dynamics Seminar, Graz, Autriche, 2022.
@conference{salvarani_1876,
title = {Exponential convergence towards consensus for non-symmetric linear first-order systems in finite and infinite dimensions},
author = {Francesco Salvarani},
year = {2022},
date = {2022-04-01},
booktitle = {Applied Analysis, Complex Systems & Dynamics Seminar},
address = {Graz, Autriche},
keywords = {},
pubstate = {accepted},
tppubtype = {conference}
}
Yakoubi, Driss; Bernardi, Christine; Maarouf, Sarra
Characteristics/finite element analysis for two incompressible fluid flows with surface tension using level set method Journal Article
In: Computer Methods In Applied Mechanics And Engineering, vol. 394, no. XXXX, pp. Paper No. 114843, 2022.
@article{yakoubi_1803,
title = {Characteristics/finite element analysis for two incompressible fluid flows with surface tension using level set method},
author = {Driss Yakoubi and Christine Bernardi and Sarra Maarouf},
url = {https://www.sciencedirect.com/science/article/pii/S0045782522001530},
year = {2022},
date = {2022-03-01},
journal = {Computer Methods In Applied Mechanics And Engineering},
volume = {394},
number = {XXXX},
pages = {Paper No. 114843},
abstract = {In this paper, we present and analyze a finite element level set method based on the method of characteristics for two phase
flow. Surface tension effects are taken into account by the CSF approach. We first write the variational formulation of the problem and investigate its well-posedness. Next, for the discretization, a first order method of characteristics approach for the
evolution of the level set function and for the material derivative of the velocity is used. The velocity and pressure unknowns
are discretized by P2? P1 Taylor-Hood finite elements. Then, in each time step, the interface transport is decoupled from the
Navier-Stokes equations. Well-posedness results for subproblems in this decoupled discrete problem are derived. Furthermore,
under high regularity assumptions, we state error estimates for our scheme. Ultimately, three computational examples illustrate
the performance of the proposed method.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Maarouf, Sarra; Bernardi, Christine; Yakoubi, Driss
Characteristics/finite element analysis for two incompressible fluid flows with surface tension using level set method Journal Article
In: Computer Methods In Applied Mechanics And Engineering, vol. 394, pp. 114843, 2022.
@article{maarouf_1803,
title = {Characteristics/finite element analysis for two incompressible fluid flows with surface tension using level set method},
author = {Sarra Maarouf and Christine Bernardi and Driss Yakoubi},
url = {https://www.sciencedirect.com/science/article/pii/S0045782522001530},
year = {2022},
date = {2022-03-01},
journal = {Computer Methods In Applied Mechanics And Engineering},
volume = {394},
pages = {114843},
abstract = {In this paper, we present and analyze a finite element level set method based on the method of characteristics for two phase
flow. Surface tension effects are taken into account by the CSF approach. We first write the variational formulation of the problem and investigate its well-posedness. Next, for the discretization, a first order method of characteristics approach for the
evolution of the level set function and for the material derivative of the velocity is used. The velocity and pressure unknowns
are discretized by P2? P1 Taylor-Hood finite elements. Then, in each time step, the interface transport is decoupled from the
Navier-Stokes equations. Well-posedness results for subproblems in this decoupled discrete problem are derived. Furthermore,
under high regularity assumptions, we state error estimates for our scheme. Ultimately, three computational examples illustrate
the performance of the proposed method.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Bobbia, Benjamin
A Dansker's Theorem for data driven local empirical measures Conference
Séminaire de l'équipe S2A Télécom Paris, Palaiseau, France, 2022.
@conference{bobbia_1856,
title = {A Dansker's Theorem for data driven local empirical measures},
author = {Benjamin Bobbia},
year = {2022},
date = {2022-03-01},
booktitle = {Séminaire de l'équipe S2A Télécom Paris},
address = {Palaiseau, France},
abstract = {Nowadays, empirical processes are well known objects. A reason that push forward theirs studies is that, in many models, we can write the estimators as images of empirical measures. In this work we investigate the case of local empirical measures built over a sub-sample with data conditioned to be in a certain area. There exists numerous results about such question, but what can we say if the area of interest is data driven ? In the present work we present a general framework which allows to derive asymptotic results for this particular empirical measures (with "low" cost in terms of technicality and assumptions). In this talk, this approach is specified for the framework of extreme values theory. In which we presente how tail and quantile estimation can be derived from a such methodology.},
keywords = {},
pubstate = {accepted},
tppubtype = {conference}
}
Yakoubi, Driss; Deteix, Jean; Kouamoa, Gerard Lionel Ndetchoua
A new energy stable fractional time stepping scheme for the Navier-Stokes/Allen-Cahn diffuse interface model Journal Article
In: Computer Methods In Applied Mechanics And Engineering, vol. 393, no. XXXX, pp. Paper No. 114759, 25, 2022.
@article{yakoubi_1802,
title = {A new energy stable fractional time stepping scheme for the Navier-Stokes/Allen-Cahn diffuse interface model},
author = {Driss Yakoubi and Jean Deteix and Gerard Lionel Ndetchoua Kouamoa},
url = {https://www.sciencedirect.com/science/article/pii/S0045782522001104},
year = {2022},
date = {2022-02-01},
journal = {Computer Methods In Applied Mechanics And Engineering},
volume = {393},
number = {XXXX},
pages = {Paper No. 114759, 25},
abstract = {In this work, we present an original time-discrete formulation of the coupled equations relating the velocity and pressure
of an unsteady flow of two immiscible fluids and the Allen-Cahn equation describing the interface between both of them. We
first prove this time-discrete formulation (based on the concept of coupled projection scheme (Deteix et al., 2014)) to be well
posed and energy stable. We then propose a new family of iterative schemes for the actual approximation of solutions. We
complete this work with numerical tests illustrating the order of accuracy and applying the new scheme on the well known
rising bubble benchmark.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Bobbia, Benjamin
Donsker's Theorem for local Data-Driven Empirical Measure Conference
Séminaire du laboratoire Modal X, Nanterre, France, 2022.
@conference{bobbia_1773,
title = {Donsker's Theorem for local Data-Driven Empirical Measure},
author = {Benjamin Bobbia},
year = {2022},
date = {2022-02-01},
booktitle = {Séminaire du laboratoire Modal X},
address = {Nanterre, France},
abstract = {Nowadays, empirical processes are well known objects. A reason that push forward theirs studies is that, in many models, we can write the estimators as images of empirical measures. In this work we investigate the case of local empirical measures built over a sub-sample with data conditioned to be in a certain area. There exists numerous results about such question, but what can we say if the area of interest is data driven ? In the present work we present a general framework which allows to derive asymptotic results for this particular empirical measures (with "low" cost in terms of technicality and assumptions). Then, we use this approach in the framework of extreme values theory deriving tail and quantile estimations.},
keywords = {},
pubstate = {accepted},
tppubtype = {conference}
}
Deteix, Jean; Kouamoa, Gerard Lionel Ndetchoua; Yakoubi, Driss
A new energy stable fractional time stepping scheme for the Navier-Stokes/Allen-Cahn diffuse interface model Journal Article
In: Computer Methods In Applied Mechanics And Engineering, vol. 393, pp. 114759, 2022.
@article{deteix_1802,
title = {A new energy stable fractional time stepping scheme for the Navier-Stokes/Allen-Cahn diffuse interface model},
author = {Jean Deteix and Gerard Lionel Ndetchoua Kouamoa and Driss Yakoubi},
url = {https://www.sciencedirect.com/science/article/pii/S0045782522001104},
year = {2022},
date = {2022-02-01},
journal = {Computer Methods In Applied Mechanics And Engineering},
volume = {393},
pages = {114759},
abstract = {In this work, we present an original time-discrete formulation of the coupled equations relating the velocity and pressure
of an unsteady flow of two immiscible fluids and the Allen-Cahn equation describing the interface between both of them. We
first prove this time-discrete formulation (based on the concept of coupled projection scheme (Deteix et al., 2014)) to be well
posed and energy stable. We then propose a new family of iterative schemes for the actual approximation of solutions. We
complete this work with numerical tests illustrating the order of accuracy and applying the new scheme on the well known
rising bubble benchmark.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Yakoubi, Driss
A projection scheme for phase change problems with convection Journal Article
In: Computers & Mathematics With Applications, vol. 108, no. 1, pp. 109-122, 2022.
@article{yakoubi_1795,
title = {A projection scheme for phase change problems with convection},
author = {Driss Yakoubi},
url = {https://www-sciencedirect-com.acces.bibl.ulaval.ca/science/article/pii/S0898122122000013?via%3Dihub},
year = {2022},
date = {2022-01-01},
journal = {Computers & Mathematics With Applications},
volume = {108},
number = {1},
pages = {109-122},
abstract = {Numerical modeling of phase change problems with convection is known to be computationally expensive. The main challenge comes from the coupling between Navier-Stokes and heat energy equations. In this paper, we develop a new scheme for phase change problems based on a projection method. The proposed method reduces the size of the system by splitting the temperature, the velocity, and the pressure fields while preserving the accuracy of the simulations. A single-domain approach using a variant of the enthalpy-porosity formulation is employed. Incompressible Navier-Stokes problem with Boussinesq approximation for thermal effects in solid and liquid regions is considered. We regularize the discontinuous variables such as latent heat and material properties by a continuous and differentiable hyperbolic tangent function. The robustness and effectiveness of the proposed scheme are illustrated by comparing the numerical results with numerical and experimental benchmark},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Guérard, Guillaume; Djebali, Sonia; Gabot, Quentin
Tourists Profiling by Interest Analysis Inproceedings
In: International Conference on Advanced Data Mining and Applications, pp. 42-53, Springer, Cham, Virtual, 2022, ISBN: 978-3-030-95407-9.
@inproceedings{guerard_1662,
title = {Tourists Profiling by Interest Analysis},
author = {Guillaume Guérard and Sonia Djebali and Quentin Gabot},
url = {https://link.springer.com/chapter/10.1007/978-3-030-95408-6_4},
issn = {978-3-030-95407-9},
year = {2022},
date = {2022-01-01},
booktitle = {International Conference on Advanced Data Mining and Applications},
volume = {13088},
pages = {42-53},
publisher = {Springer, Cham},
address = {Virtual},
abstract = {With the recent digital revolution, analyzing of tourists' behaviors
and research elds associated with it have changed profoundly.
It is now easier to examine behaviors of tourists using digital traces they
leave during their travels. The studies conducted on diverse aspects of
tourism focus on quantitative aspects of digital traces to reach its conclusions.
In this paper, we suggest a study focused on both qualitative and
quantitative aspect of digital traces to understand the dynamics governing
tourist behavior, especially those concerning attractions networks.},
keywords = {},
pubstate = {published},
tppubtype = {inproceedings}
}
Montiel, Antoine; Sargueil, Paul; Nguyen, Thuy; Rountree, Cindy; Geertsen, Valérie; Guenoun, Patrick; Bonamy, Daniel
Mechanical & fracture behaviour of microlattice metamaterial with disordered architecture Conference
Mécanique des Matériaux Architecturés, MacaMat Aussois, France, 2022.
@conference{montiel_1775,
title = {Mechanical & fracture behaviour of microlattice metamaterial with disordered architecture},
author = {Antoine Montiel and Paul Sargueil and Thuy Nguyen and Cindy Rountree and Valérie Geertsen and Patrick Guenoun and Daniel Bonamy},
url = {https://aussois2022.sciencesconf.org/},
year = {2022},
date = {2022-01-01},
booktitle = {Mécanique des Matériaux Architecturés},
address = {Aussois, France},
organization = {MacaMat},
keywords = {},
pubstate = {published},
tppubtype = {conference}
}
Haddad, Mireille El; Belhamadia, Youssef; Deteix, Jean; Yakoubi, Driss
A projection scheme for phase change problems with convection Journal Article
In: Computers & Mathematics With Applications, vol. 108, no. 1, pp. 109-122, 2022.
@article{el_haddad_1795,
title = {A projection scheme for phase change problems with convection},
author = {Mireille El Haddad and Youssef Belhamadia and Jean Deteix and Driss Yakoubi},
url = {https://www-sciencedirect-com.acces.bibl.ulaval.ca/science/article/pii/S0898122122000013?via%3Dihub},
year = {2022},
date = {2022-01-01},
journal = {Computers & Mathematics With Applications},
volume = {108},
number = {1},
pages = {109-122},
abstract = {Numerical modeling of phase change problems with convection is known to be computationally expensive. The main challenge comes from the coupling between Navier-Stokes and heat energy equations. In this paper, we develop a new scheme for phase change problems based on a projection method. The proposed method reduces the size of the system by splitting the temperature, the velocity, and the pressure fields while preserving the accuracy of the simulations. A single-domain approach using a variant of the enthalpy-porosity formulation is employed. Incompressible Navier-Stokes problem with Boussinesq approximation for thermal effects in solid and liquid regions is considered. We regularize the discontinuous variables such as latent heat and material properties by a continuous and differentiable hyperbolic tangent function. The robustness and effectiveness of the proposed scheme are illustrated by comparing the numerical results with numerical and experimental benchmark},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Boudin, Laurent; Salvarani, Francesco; Trélat, Emmanuel
Exponential Convergence Towards Consensus for Non-Symmetric Linear First-Order Systems in Finite and Infinite Dimensions Journal Article
In: Siam Journal On Mathematical Analysis, vol. 54, no. 3, pp. 2727-2752, 2022.
@article{boudin_1819,
title = {Exponential Convergence Towards Consensus for Non-Symmetric Linear First-Order Systems in Finite and Infinite Dimensions},
author = {Laurent Boudin and Francesco Salvarani and Emmanuel Trélat},
url = {https://epubs.siam.org/doi/abs/10.1137/21M1416102},
year = {2022},
date = {2022-01-01},
journal = {Siam Journal On Mathematical Analysis},
volume = {54},
number = {3},
pages = {2727-2752},
abstract = {We consider finite and infinite-dimensional first-order consensus systems with time- constant interaction coefficients. For symmetric coefficients, convergence to consensus is classically established by proving, for instance, that the usual variance is an exponentially decreasing Lyapunov function. We investigate here the convergence to consensus in the non-symmetric case: we identify a positive weight which allows us to define a weighted mean corresponding to the consensus and obtain exponential convergence towards consensus. Moreover, we compute the sharp exponential decay rate.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Gürcan, Özgür; Anderson, Johan; Moradi, Sara; Biancalani, Alessandro; Morel, Pierre
Phase and amplitude evolution in the network of triadic interactions of the Hasegawa-Wakatani system Journal Article
In: Physics Of Plasmas, vol. 29, no. 5, pp. 052306, 2022.
@article{gurcan_1825,
title = {Phase and amplitude evolution in the network of triadic interactions of the Hasegawa-Wakatani system},
author = {Özgür Gürcan and Johan Anderson and Sara Moradi and Alessandro Biancalani and Pierre Morel},
url = {https://aip.scitation.org/doi/10.1063/5.0089073},
year = {2022},
date = {2022-01-01},
journal = {Physics Of Plasmas},
volume = {29},
number = {5},
pages = {052306},
abstract = {The Hasegawa-Wakatani system, commonly used as a toy model of dissipative drift waves in fusion devices, is revisited with considerations
of phase and amplitude dynamics of its triadic interactions. It is observed that a single resonant triad can saturate via three way phase
locking, where the phase differences between dominant modes converge to constant values as individual phases increase in time. This allows
the system to have approximately constant amplitude solutions. Non-resonant triads show similar behavior only when one of its legs is a
zonal wave number. However, when an additional triad, which is a reflection of the original one with respect to the y axis is included, the
behavior of the resulting triad pair is shown to be more complex. In particular, it is found that triads involving small radial wave numbers
(large scale zonal flows) end up transferring their energy to the subdominant mode which keeps growing exponentially, while those involving
larger radial wave numbers (small scale zonal flows) tend to find steady chaotic or limit cycle states (or decay to zero). In order to study the
dynamics in a connected network of triads, a network formulation is considered, including a pump mode, and a number of zonal and non-
zonal subdominant modes as a dynamical system. It was observed that the zonal modes become clearly dominant only when a large number
of triads are connected. When the zonal flow becomes dominant as a ?collective mean field,? individual interactions between modes become
less important, which is consistent with the inhomogeneous wave-kinetic picture. Finally, the results of direct numerical simulation are dis-
cussed for the same parameters, and various forms of the order parameter are computed. It is observed that nonlinear phase dynamics results
in a flattening of the large scale phase velocity as a function of scale in direct numerical simulations.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}