Multi-scale modeling of clogging in permeable pavements using CFD–DEM coupling / Modélisation multi-échelle du colmatage des chaussées perméables par couplage CFD–DEM

The candidate will join the Civil Engineering and Energy team at the Icube laboratory (UMR 7357) (icube.unistra.fr), specifically the research group focused on the behavior of structures under complex loading, which is based at the INSA Strasbourg premises.

The group’s activities focus on the study and modeling of the behavior of civil engineering structures and infrastructures in their environment, using various multi-scale numerical approaches (FEM, DEM, BEM), rheological laws associated with different materials, and experimental devices for characterization under small and large deformations, as well as hydraulic properties.

INSA Strasbourg is a public scientific, cultural, and professional institution (EPSCP). The school, whose origins date back to 1875, joined the INSA Group in 2003. As a Grande École for engineers and a school of architecture under the supervision of the Ministry of Higher Education, Research, and Innovation, its engineering programs are accredited by the Commission des Titres d’Ingénieur (CTI), while its architecture program is accredited by the Ministry of Culture’s Cultural, Scientific, and Technical Commission.

INSA Strasbourg welcomes approximately 2,000 students on its campus, located on the Esplanade university campus, just a short distance from the city center, in the heart of the European capital.

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Le candidat intégrera l’équipe Génie Civil et Energétique du laboratoire Icube (UMR 7357) (https://icube.unistra.fr/) et plus particulièrement le groupe de recherche comportement des ouvrages sous sollicitations complexes qui se trouve dans les locaux de l’INSA de Strasbourg.

Les activités du groupe portent sur l’étude et la modélisation du comportement des structures et des infrastructures du Génie Civil dans leur environnement en considérant différentes approches numériques multi-échelles (FEM, DEM, BEM), les lois rhéologiques associées aux différents matériaux et les dispositifs expérimentaux de caractérisation en petites et grandes transformations, et des propriétés hydrauliques.

L’INSA Strasbourg est un établissement public à caractère scientifique culturel et professionnel (EPSCP). L’école, dont les origines remontent à 1875, a rejoint le Groupe INSA en 2003.

Grande école d’ingénieurs et école d’architecture sous la tutelle du ministère de l’Enseignement supérieur, de la Recherche et de l’Innovation, ses formations d’ingénieurs sont accréditées par la commission des titres d’ingénieur, celle d’architecte est accréditée par la commission culturelle, scientifique et technique du ministère de la Culture.

L’INSA Strasbourg accueille environ 2 000 étudiants dans ses locaux, sur le campus universitaire de l’esplanade, à deux pas du centre ville, au cœur de la capitale européenne.

Title: Multi-scale modeling of clogging in permeable pavements using CFD–DEM coupling

The postdoctoral researcher will be responsible for developing a multi-scale numerical approach dedicated to modeling the evolution of permeability in permeable and draining pavement layers, in relation to progressive clogging mechanisms induced by cohesive and non-cohesive sediments. This work is part of the ANR-I OpenPav project.

The research will focus on the influence of:

the properties of the pore network,

the grain size distribution of the materials,

the nature of the sediments,

deposition mechanisms, arching effects, and accumulation,

on the kinetics of hydraulic conductivity loss. Special attention will be given to resolved and unresolved CFD–DEM coupling.

Main activities:

Develop numerical models to study the permeability of draining layers.

Implement resolved CFD–DEM simulations at the pore scale.

Develop unresolved CFD–DEM simulations to study sediment accumulation in voids.

Investigate the influence of the porous microstructure:

Porosity

Tortuosity

Connectivity

Pore size distribution

For sediments, analyze the effect of:

Grain size distribution

Concentration

Cohesion

Establish laws for the evolution of permeability as a function of clogging.

Conduct parametric studies.

Contribute to scientific dissemination:

Publications

Conferences

Project reports

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TITRE : Modélisation multi-échelle du colmatage des chaussées perméables par couplage CFD–DEM.

Le/la post-doctorant(e) aura pour mission de développer une approche numérique multi-échelle dédiée à la modélisation de l’évolution de la perméabilité des couches de chaussées perméables et drainantes, en lien avec les mécanismes de colmatage progressif induits par des sédiments cohésifs et non cohésifs. Les travaux sont menés dans le cadre de l’ANR-I OpenPav.

Le travail portera sur l’influence :

• des propriétés du réseau poral,
• de la granulométrie des matériaux,
• de la nature des sédiments,
• des mécanismes de dépôt, d’effet de voûte et d’accumulation,

sur la cinétique de perte de conductivité hydraulique. Une attention particulière sera portée au couplage CFD–DEM en modes résolu et non résolu. 

Activités principales :

• Développer des modèles numériques pour l’étude de la perméabilité des couches drainantes  
• Mettre en œuvre des simulations CFD–DEM résolues à l’échelle du pore
• Développer des simulations CFD–DEM non résolues pour l’étude du cumul de sédiments dans les vides

Etudier l'influence de la microstructure porale:

• Prorosité 
• Tortuosité
•  Connectivité
• Distribution de la taille des pores

Pour les sédiments analyser l'effet de :

•  la ganulométrie
• la concentration
• la cohésion 

Etablir les lois d’évolution de la perméabilité en fonction du colmatage 

Réaliser des campagnes paramétriques 

Participer à la valorisation scientifique : 

• •  
  • Publications
  • Conférences
  • Rapports de projet

Education level:
PhD in Fluid Mechanics, Computational Mechanics, Granular Materials, or Porous Media.

Experience level:

Recent PhD graduate or initial postdoctoral experience.

Prior experience in the following will be highly valued:

CFD–DEM

Multiphysics simulation

Porous media

Additional experience in the following areas will be considered an asset:

Clogging

Filtration

Cohesive sediments

Drainage materials

Knowledge and expertise:

The candidate must have strong knowledge in:

Computational fluid mechanics

Porous media

Particle transport

Granular mechanics

Clogging/filtration phenomena

Hydraulics of porous materials

Multiphysics numerical methods

The following knowledge will be appreciated:

Permeable pavements

Urban hydrology

Road granular materials

Skills:

Proficiency in CFD tools:

OpenFOAM

ANSYS Fluent

Or equivalent

Experience with DEM:

LIGGGHTS

YADE

CFDEM

Or similar tools

Python/C++ development

Numerical data analysis

Post-processing:

Paraview

Python

MATLAB

Ability to develop constitutive laws or reduced-order models

Scientific writing in English

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Title : Improving the durability of open porous asphalt pavements in urban areas

Several WP exist with many tests about the mechanical behaviour, permeability tests and clogging tests.

WP2 has two main objectives, i. e. (i.) to quantify the susceptibility of PA pavements to damage related to
clogging, and (ii.) to identify the key factors of influence for clogging. For this purpose, numerical analysis is
used based on the binder and mixture parameters derived in WP1.
Multiphysical models are developed to reproduce the mechanical behavior of PA pavements under clogging
(Task 2.1) and subsequently to freeze-thaw cycles (Task 2.2). Simulations of 2D and 3D samples under
homogeneous conditions are adopted.
 

Task 2.1 addresses the impact of clogging on PA layer permeability, using Discrete Element Modeling (DEM) for
granular material structure and sediments, and the simulation of water flow through PA layers using
Computational Fluid Dynamics (CFD). The solid and fluid equations are coupled in order to define permeability
of PA layers.
 

One fundamental goal of Task 2.1 is to quantitatively reproduce the evolution of permeability as a function of
solid injection during the clogging tests. This objective relies on various pieces of information provided by
multiple experiments.

Measurements of porosity, along with CT scan assessments of microstructure (conducted in WP1 and WP2),
yield a realistic description of the voids. This information is used to represent DEM samples of the PA mixture.
Subsequent measurements after clogging tests enable the verification of numerical model results concerning
the distribution of sediments within the porous medium.
Developing a robust model for permeability based on porosity and associated sediment mass balance facilitates
the extrapolation of results beyond the project's experiments. This allows the analysis of PA materials with
different porosities, water flow velocities, and solid concentrations. The derivation of general and simplified
equations related to measurable system quantities (porosity, permeability, granulometry, fluid flow, solid
concentration, etc.) is a crucial tool for the design of PA pavements.
A second goal of Task 2.1 is to create a representative clogged microstructure of PA pavements for use in Task
2.2.