Sophie Roman

University of Orléans | UO · Institut des Sciences de la Terre d'Orléans

Clogging of porous media by particulate flow is a complex process that relies on many different physical phenomena and depends on a wide range of parameters including particle size and concentration, flow conditions, and the geometry of porous microstructure. We developed a high-resolution pore-scale simulator to investigate particle depositions an...

Plain Language Summary Surface and borehole geoelectrical prospecting is used to understand the structure of the subsurface and the functioning of the processes that take place there. These processes include flows and changes in groundwater stocks, transport of pollutants, and dissolution and precipitation of minerals. The complexity of studying th...

We miniaturize geoelectrical acquisition using advanced microfabrication technologies to investigate coupled processes in the critical zone. We focus on the development of the complex electrical conductivity acquisition with the spectral induced polarization (SIP) method on a microfluidic chip equipped with electrodes. SIP is an innovative detectio...

Hypothesis: Understanding interfacial mass transfer during dissolution of gas in a liquid is vital for optimising large-scale carbon capture and storage operations. While the dissolution of CO2 bubbles in reservoir brine is a crucial mechanism towards safe CO2 storage, it is a process that occurs at the pore-scale and is not yet fully understood. D...

Immiscible two-phase flow through porous media is composed of a series of pore invasions; however, the consequences of pore-scale processes on macroscopic fluid front behavior remain to be clarified. In this work, we perform an analytical and experimental investigation of front behavior and pore invasions dynamics during drainage for various viscos...

This manuscript presents a benchmark problem for the simulation of single-phase flow, reactive transport, and solid geometry evolution at the pore scale. The problem is organized in three parts that focus on specific aspects: flow and reactive transport (part I), dissolution-driven geometry evolution in two dimensions (part II), and an experimental...

Computational microfluidics for geosciences is the third leg of the scientific strategy that includes microfluidic experiments and high-resolution imaging for deciphering coupled processes in geological porous media. This modeling approach solves the fundamental equations of continuum mechanics in the exact geometry of porous materials. Computation...

Hydrodynamic dispersion is a crucial mechanism for modelling contaminant transport in subsurface engineering and water resources management whose determination remains challenging. We use Digital Rock Physics (DRP) to evaluate the longitudinal dispersion of a sandpack. From a three-dimensional image of a porous sample obtained with X-ray microtomog...

An in-depth understanding of dissolution and precipitation of minerals in porous and fractured porous media and the complex feedback on the transport of fluids is essential for various subsurface applications. In this context, we developed a novel non-destructive “lab-on-chip” approach for quantitative in situ assessments of mineralogical changes i...

Hypothesis: The effects of mutual transfer of momentum between two immiscible flowing fluids in porous media are not well understood nor predictable yet. From considerations at the pore-scale, it should be possible to determine whether and to what extent interfacial viscous coupling effects are significant. Experiments: We visualize the velocity...

A micro-continuum approach is proposed to simulate the dissolution of solid minerals at the pore scale in the presence of multiple fluid phases. The approach employs an extended Darcy–Brinkman–Stokes formulation that accounts for the interfacial tension between the two immiscible fluid phases and the moving contact line at the mineral surface. The...

A micro-continuum approach is proposed to simulate the dissolution of solid minerals at the pore scale under single-phase flow conditions. The approach employs a Darcy–Brinkman–Stokes formulation and locally averaged conservation laws combined with immersed boundary conditions for the chemical reaction at the solid surface. The methodology compares...

When a wetting liquid is displaced by air in a capillary tube, a wetting film develops between the tube wall and the air that is responsible for the snap-off mechanism of the gas phase. By dissolving a dye in the wetting phase it is possible to relate a measure of the absorbance in the capillary to the thickness of liquid films. These data could be...

Silicon-based microfluidic devices, so-called micromodels in this application, are particularly useful laboratory tools for the direct visualization of fluid flow revealing pore-scale mechanisms controlling flow and transport phenomena in natural porous media. Current microfluidic devices with uniform etched depths, however, are limited when repres...

We perform micro-PIV measurements in micromodels using very simple optical equipment combined with efficient image acquisition and processing. The pore-scale velocity distributions are obtained for single-phase flow in porous media with a typical pore size of 5-40 mu m at a resolution of 1.8 mu m x 1.8 mu m vector grid. Because the application of m...

Studying the transport of ions through single-walled carbon nanotubes (SWCNTs) necessitate the fabrication of a fluidic setup integrating carbon nanotubes. In this article, we report on the development of a simple fabrication protocol of SWCNTs fluidic devices. This protocol allows an excellent control of the system features and of the experimental...

There is growing interest in using advanced imaging techniques to describe the complex pore-space of natural rocks at resolutions that allow for quantitative assessment of the flow and transport behaviors in these complex media. Here, we focus on representations of the complex pore-space obtained from X-ray microtomography and the subsequent use of...

Despite the development of microfluidics, experimental challenges are considerable for achieving a quantitative study of phase separation, i.e., the non-proportional distribution of Red Blood Cells (RBCs) and suspending fluid, in microfluidic bifurcations with channels smaller than 20 μm. Yet, a basic understanding of phase separation in such small...

We perform micro-PIV measurements in micromodels using very simple optical equipment combined with efficient image acquisition and processing. The pore-scale velocity distributions are obtained for single-phase flow in porous media with a typical pore size of 5–40 µm at a resolution of 1.8μm×1.8μm vector grid. Because the application of micro-PIV i...

Le sang est une suspension concentrée (45 % en volume) de cellules déformables, les globules rouges, dans un liquide newtonien, le plasma. Dans la microcirculation, i.e. le sous-ensemble du système de circulation sanguine où s’effectuent les échanges de matière entre le sang et les tissus, les diamètres des vaisseaux sont inférieurs à 100 μm, ce qu...

Egalement paru au 37ème Congrès de la Société de Biomécanique, à Toulouse, du 16 au 19 octobre 2012.

Oxygen and nutrient delivery to living tissues, as well as metabolic waste removal, are essentially determined by the dynamics of blood flow in microvascular networks. In these vessels, measuring the velocity distribution of red blood cells (RBCs) is still challenging. One of the most popular techniques used for that purpose is the Dual-Slit (DS),...

Oxygen and nutrient delivery to living tissues, as well as metabolic waste removal, are essentially determined by blood-flow dynamics in microvascular networks. Blood is a suspension of red blood cells (RBCs) at a high concentration in a Newtonian aqueous solution, called plasma. Because of the important size of RBCs relative to the vessels dimensi...

The homogenization theory in linear elasticity is applied to a periodic array of cylindrical inclusions in rectangular pattern extending to infinity in the inclusions axial direction, such that the deformation of tissue along this lastdirection is negligible. In the plane of deformation, the homogenization scheme is based on the average strain ener...

In this paper, an MRI image segmentation method based on two-dimensional survival exponential entropy (2DSEE) and particle swarm optimization (PSO) is proposed. The 2DSEE technique does not consider only the cumulative distribution of the gray level information but also takes advantage of the spatial information using the 2D-histogram. The problem...