https://sam.ensam.eu:443 The DSpace digital repository system captures, stores, indexes, preserves, and distributes digital research material. Sun, 07 Jun 2026 02:37:46 GMT 2026-06-07T02:37:46Z http://hdl.handle.net/10985/9755 Towards a new method of porosimetry: principles and experiments RODRIGUEZ DE CASTRO, Antonio; AHMADI-SENICHAULT, Azita; BRUNEAU, Denis; OMARI, Aziz Current experimental methods used to determine pore size distributions (PSD) in porous media present several drawbacks such as toxicity of employed fluids (e.g. mercury porosimetry). Theoretical basis of a new method to obtain the PSD of porous media has been proposed in the literature [1, 2] ... Tue, 01 Jan 2013 00:00:00 GMT http://hdl.handle.net/10985/9755 2013-01-01T00:00:00Z RODRIGUEZ DE CASTRO, Antonio AHMADI-SENICHAULT, Azita BRUNEAU, Denis OMARI, Aziz Current experimental methods used to determine pore size distributions (PSD) in porous media present several drawbacks such as toxicity of employed fluids (e.g. mercury porosimetry). Theoretical basis of a new method to obtain the PSD of porous media has been proposed in the literature [1, 2] ... http://hdl.handle.net/10985/9722 Towards a new method of porosimetry: principles and experiments RODRIGUEZ DE CASTRO, Antonio; OMARI, Aziz; AHMADI-SENICHAULT, Azita; BRUNEAU, Denis Abstract Current experimental methods used to determine pore size distributions (PSD) of porous media present several drawbacks such as toxicity of the employed fluids (e.g., mercury porosimetry). The theoretical basis of a new method to obtain the PSD by injecting yield stress fluids through porous media and measuring the flow rate Q at several pressure gradients ∇P was proposed in the literature. On the basis of these theoretical considerations, an intuitive approach to obtain PSD from Q(∇P) is presented in this work. It relies on considering the extra increment of Q when ∇P is increased, as a consequence of the pores of smaller radius newly incorporated to the flow. This procedure is first tested and validated on numerically generated experiments. Then, it is applied to exploit data coming from laboratory experiments and the obtained PSD showgood agreement with the PSD deduced frommercury porosimetry. Tue, 01 Jan 2013 00:00:00 GMT http://hdl.handle.net/10985/9722 2013-01-01T00:00:00Z RODRIGUEZ DE CASTRO, Antonio OMARI, Aziz AHMADI-SENICHAULT, Azita BRUNEAU, Denis Abstract Current experimental methods used to determine pore size distributions (PSD) of porous media present several drawbacks such as toxicity of the employed fluids (e.g., mercury porosimetry). The theoretical basis of a new method to obtain the PSD by injecting yield stress fluids through porous media and measuring the flow rate Q at several pressure gradients ∇P was proposed in the literature. On the basis of these theoretical considerations, an intuitive approach to obtain PSD from Q(∇P) is presented in this work. It relies on considering the extra increment of Q when ∇P is increased, as a consequence of the pores of smaller radius newly incorporated to the flow. This procedure is first tested and validated on numerically generated experiments. Then, it is applied to exploit data coming from laboratory experiments and the obtained PSD showgood agreement with the PSD deduced frommercury porosimetry. http://hdl.handle.net/10985/9978 On the Determination of Pore size distribution from Injection of yield stress fluids through model porous media RODRIGUEZ DE CASTRO, Antonio; MALVAULT, Guillaume; AHMADI-SENICHAULT, Azita; AMBARI, Abdelhak; BRUNEAU, Denis; CHAMPMARTIN, Stephane; OMARI, Aziz Current methods used to determine pore size distribution of porous media (as mercury porosimetry) present several drawbacks the main of which is their toxicity An innovative method using yield stress fluids has been proposed in the literature. The main idea in these works is that using fluids with a threshold below which the fluid does not flow allows obtaining the pore size distribution by simply measuring the evolution of the flow rate versus pressure gradient. In fact this attractive method should be carefully handled and very precise experimental results are needed to make the method tractable in order to meet the targeted objective. This will be discussed through presentation of our recent experimental results. In these experiments two kinds of fluids where specifically formulated and rheologically characterized. These fluids were injected in both simple and complex artificial porous media and flow rate-pressure gradient relationships where established allowing us to estimate the pore size distribution. Sun, 01 Jan 2012 00:00:00 GMT http://hdl.handle.net/10985/9978 2012-01-01T00:00:00Z RODRIGUEZ DE CASTRO, Antonio MALVAULT, Guillaume AHMADI-SENICHAULT, Azita AMBARI, Abdelhak BRUNEAU, Denis CHAMPMARTIN, Stephane OMARI, Aziz Current methods used to determine pore size distribution of porous media (as mercury porosimetry) present several drawbacks the main of which is their toxicity An innovative method using yield stress fluids has been proposed in the literature. The main idea in these works is that using fluids with a threshold below which the fluid does not flow allows obtaining the pore size distribution by simply measuring the evolution of the flow rate versus pressure gradient. In fact this attractive method should be carefully handled and very precise experimental results are needed to make the method tractable in order to meet the targeted objective. This will be discussed through presentation of our recent experimental results. In these experiments two kinds of fluids where specifically formulated and rheologically characterized. These fluids were injected in both simple and complex artificial porous media and flow rate-pressure gradient relationships where established allowing us to estimate the pore size distribution. http://hdl.handle.net/10985/17210 Flow of yield stress and Carreau fluids through rough-walled rock fractures: Prediction and experiments RADILLA, Giovanni; RODRIGUEZ DE CASTRO, Antonio Many natural phenomena in geophysics and hydrogeology involve the flow of non-Newtonian fluids through natural rough-walled fractures. Therefore, there is considerable interest in predicting the pressure drop generated by complex flow in these media under a given set of boundary conditions. However, this task is markedly more challenging than the Newtonian case given the coupling of geometrical and rheological parameters in the flow law. The main contribution of this paper is to propose a simple method to predict the flow of commonly used Carreau and yield stress fluids through fractures. To do so, an expression relating the “in-situ” shear viscosity of the fluid to the bulk shear-viscosity parameters is obtained. Then, this “in-situ” viscosity is entered in the macroscopic laws to predict the flow rate-pressure gradient relations. Experiments with yield stress and Carreau fluids in two replicas of natural fractures covering a wide range of injection flow rates are presented and compared to the predictions of the proposed method. Our results show that the use of a constant shift parameter to relate “in-situ” and bulk shear viscosity is no longer valid in the presence of a yield stress or a plateau viscosity. Consequently, properly representing the dependence of the shift parameter on the flow rate is crucial to obtain accurate predictions. The proposed method predicts the pressure drop in a rough-walled fracture at a given injection flow rate by only using the shear rheology of the fluid, the hydraulic aperture of the fracture and the inertial coefficients as inputs. Sun, 01 Jan 2017 00:00:00 GMT http://hdl.handle.net/10985/17210 2017-01-01T00:00:00Z RADILLA, Giovanni RODRIGUEZ DE CASTRO, Antonio Many natural phenomena in geophysics and hydrogeology involve the flow of non-Newtonian fluids through natural rough-walled fractures. Therefore, there is considerable interest in predicting the pressure drop generated by complex flow in these media under a given set of boundary conditions. However, this task is markedly more challenging than the Newtonian case given the coupling of geometrical and rheological parameters in the flow law. The main contribution of this paper is to propose a simple method to predict the flow of commonly used Carreau and yield stress fluids through fractures. To do so, an expression relating the “in-situ” shear viscosity of the fluid to the bulk shear-viscosity parameters is obtained. Then, this “in-situ” viscosity is entered in the macroscopic laws to predict the flow rate-pressure gradient relations. Experiments with yield stress and Carreau fluids in two replicas of natural fractures covering a wide range of injection flow rates are presented and compared to the predictions of the proposed method. Our results show that the use of a constant shift parameter to relate “in-situ” and bulk shear viscosity is no longer valid in the presence of a yield stress or a plateau viscosity. Consequently, properly representing the dependence of the shift parameter on the flow rate is crucial to obtain accurate predictions. The proposed method predicts the pressure drop in a rough-walled fracture at a given injection flow rate by only using the shear rheology of the fluid, the hydraulic aperture of the fracture and the inertial coefficients as inputs. http://hdl.handle.net/10985/17199 On the rapid manufacturing process of functional 3D printed sand molds MITRA, Saptarshee; EL MANSORI, Mohamed; RODRIGUEZ DE CASTRO, Antonio 3D printing sand mold technology offers an opportunity for the foundry industry to rethink old casting approaches and to revive the manufacturing approach using computer models. One of the major concerns in sand molding using 3D printing is the functional characterization of the 3D printed molds as its mechanical and mass transport properties. This research paper discusses the effects of binder content on the mechanical strength and the permeability of 3DP sand molds at different curing conditions. The local permeability of the 3DP specimen was measured as a function of the injection flow rate in order to quantify the inertial pressure effects. The mechanical strength of the 3DP sand molds was characterized using traditional three-point bending strength measurements. The results show that the mechanical strength of the printed molds is deeply dependent on the amount of binder and the curing process. The 3PB strength was found to increase when cured at 100 °C and decrease when cured at 200 °C for all binder contents. The 3PB strength attains its maximum when cured at 100 °C for 2 h for all binder content. In contrast, no significant effect of the amount of binder on the initial permeability of the samples before curing was observed within the functional range of binder mass fraction (1.02–1.98 %). Maximum permeability is attained at the same conditions as the 3PB strength. Therefore, the mechanical strength of the sample can be optimized within the investigated range of binder contents without resulting in any significant decrease in permeability. Tue, 01 Jan 2019 00:00:00 GMT http://hdl.handle.net/10985/17199 2019-01-01T00:00:00Z MITRA, Saptarshee EL MANSORI, Mohamed RODRIGUEZ DE CASTRO, Antonio 3D printing sand mold technology offers an opportunity for the foundry industry to rethink old casting approaches and to revive the manufacturing approach using computer models. One of the major concerns in sand molding using 3D printing is the functional characterization of the 3D printed molds as its mechanical and mass transport properties. This research paper discusses the effects of binder content on the mechanical strength and the permeability of 3DP sand molds at different curing conditions. The local permeability of the 3DP specimen was measured as a function of the injection flow rate in order to quantify the inertial pressure effects. The mechanical strength of the 3DP sand molds was characterized using traditional three-point bending strength measurements. The results show that the mechanical strength of the printed molds is deeply dependent on the amount of binder and the curing process. The 3PB strength was found to increase when cured at 100 °C and decrease when cured at 200 °C for all binder contents. The 3PB strength attains its maximum when cured at 100 °C for 2 h for all binder content. In contrast, no significant effect of the amount of binder on the initial permeability of the samples before curing was observed within the functional range of binder mass fraction (1.02–1.98 %). Maximum permeability is attained at the same conditions as the 3PB strength. Therefore, the mechanical strength of the sample can be optimized within the investigated range of binder contents without resulting in any significant decrease in permeability. http://hdl.handle.net/10985/17200 The effect of ageing process on three-point bending strength and permeability of 3D printed sand molds MITRA, Saptarshee; EL MANSORI, Mohamed; RODRIGUEZ DE CASTRO, Antonio The objective of this paper was to investigate the effects of curing parameters (i.e., temperature and time), on the permeability and mechanical strength of the printed molds. Several sets of samples were hence produced with a state-of-the-art 3D printer using well-characterized silica sand and furan resin binder. Then, experiments were performed in which the evolution over time of the three-point bending (3 PB) strength and permeability of the samples were monitored at three different curing temperatures. From these measurements, both the individual and combined effects of curing temperature and time on the functionality of the 3D printed molds were assessed. Moreover, loss-on-ignition (LOI) tests were also performed in order to relate the loss of binder mass to the variation in permeability and mechanical strength of the samples. The results showed that the printed molds can be stored at room temperature for a long time before being used, roughly preserving the initial properties. No significant change in 3 PB strength was observed when curing at 100 °C. In contrast, the permeability was shown to decrease with increasing curing temperature. Mon, 01 Jan 2018 00:00:00 GMT http://hdl.handle.net/10985/17200 2018-01-01T00:00:00Z MITRA, Saptarshee EL MANSORI, Mohamed RODRIGUEZ DE CASTRO, Antonio The objective of this paper was to investigate the effects of curing parameters (i.e., temperature and time), on the permeability and mechanical strength of the printed molds. Several sets of samples were hence produced with a state-of-the-art 3D printer using well-characterized silica sand and furan resin binder. Then, experiments were performed in which the evolution over time of the three-point bending (3 PB) strength and permeability of the samples were monitored at three different curing temperatures. From these measurements, both the individual and combined effects of curing temperature and time on the functionality of the 3D printed molds were assessed. Moreover, loss-on-ignition (LOI) tests were also performed in order to relate the loss of binder mass to the variation in permeability and mechanical strength of the samples. The results showed that the printed molds can be stored at room temperature for a long time before being used, roughly preserving the initial properties. No significant change in 3 PB strength was observed when curing at 100 °C. In contrast, the permeability was shown to decrease with increasing curing temperature. http://hdl.handle.net/10985/15179 Non-Darcian flow of shear-thinning fluids through packed beads: Experiments and predictions using Forchheimer’s law and Ergun’s equation RADILLA, Giovanni; RODRIGUEZ DE CASTRO, Antonio The flow of shear-thinning fluids through unconsolidated porous media is present in a number of impor- tant industrial applications such as soil depollution, Enhanced Oil Recovery or filtration of polymeric liq- uids. Therefore, predicting the pressure drop–flow rate relationship in model porous media has been the scope of major research efforts during the last decades. Although the flow of Newtonian fluids through packs of spherical particles is well understood in most cases, much less is known regarding the flow of shear-thinning fluids as high molecular weight polymer aqueous solutions. In particular, the experimen- tal data for the non-Darcian flow of shear-thinning fluids are scarce and so are the current approaches for their prediction. Given the relevance of non-Darcian shear-thinning flow, the scope of this work is to perform an experimental study to systematically evaluate the effects of fluid shear rheology on the flow rate–pressure drop relationships for the non-Darcian flow through different packs of glass spheres. To do so, xanthan gum aqueous solutions with different polymer concentrations are injected through four packs of glass spheres with uniform size under Darcian and inertial flow regimes. A total of 1560 experimen- tal data are then compared with predictions coming from different methods based on the extension of widely used Ergun’s equation and Forchheimer’s law to the case of shear thinning fluids, determining the accuracy of these predictions. The use of a proper definition for Reynolds number and a realistic model to represent the rheology of the injected fluids results in the porous media are shown to be key aspects to successfully predict pressure drop–flow rate relationships for the inertial shear-thinning flow in packed beads. Sun, 01 Jan 2017 00:00:00 GMT http://hdl.handle.net/10985/15179 2017-01-01T00:00:00Z RADILLA, Giovanni RODRIGUEZ DE CASTRO, Antonio The flow of shear-thinning fluids through unconsolidated porous media is present in a number of impor- tant industrial applications such as soil depollution, Enhanced Oil Recovery or filtration of polymeric liq- uids. Therefore, predicting the pressure drop–flow rate relationship in model porous media has been the scope of major research efforts during the last decades. Although the flow of Newtonian fluids through packs of spherical particles is well understood in most cases, much less is known regarding the flow of shear-thinning fluids as high molecular weight polymer aqueous solutions. In particular, the experimen- tal data for the non-Darcian flow of shear-thinning fluids are scarce and so are the current approaches for their prediction. Given the relevance of non-Darcian shear-thinning flow, the scope of this work is to perform an experimental study to systematically evaluate the effects of fluid shear rheology on the flow rate–pressure drop relationships for the non-Darcian flow through different packs of glass spheres. To do so, xanthan gum aqueous solutions with different polymer concentrations are injected through four packs of glass spheres with uniform size under Darcian and inertial flow regimes. A total of 1560 experimen- tal data are then compared with predictions coming from different methods based on the extension of widely used Ergun’s equation and Forchheimer’s law to the case of shear thinning fluids, determining the accuracy of these predictions. The use of a proper definition for Reynolds number and a realistic model to represent the rheology of the injected fluids results in the porous media are shown to be key aspects to successfully predict pressure drop–flow rate relationships for the inertial shear-thinning flow in packed beads. http://hdl.handle.net/10985/15199 Non-Darcian flow experiments of shear-thinning fluids through rough-walled rock fractures RADILLA, Giovanni; RODRIGUEZ DE CASTRO, Antonio Understanding non-Darcian flow of shear-thinning fluids through rough-walled rock fractures is of vital importance in a number of industrial applications such as hydrogeology or petroleum engineering. Different laws are available to express the deviations from linear Darcy law due to inertial pressure losses. In particular, Darcy’s law is often extended through addition of quadratic and cubic terms weighted by two inertial coefficients depending on the strength of the inertia regime. The relations between the effective shear viscosity of the fluid and the apparent viscosity in porous media when inertial deviations are negligible were extensively studied in the past. However, only recent numerical works have investigated the superposition of both inertial and shear-thinning effects, finding that the same inertial coefficients obtained for non-Darcian Newtonian flow applied in the case of shear-thinning fluids. The objective of this work is to experimentally validate these results, extending their applicability to the case of rough-walled rock fractures. To do so, flow experiments with aqueous polymer solutions have been conducted using replicas of natural fractures, and the effects of polymer concentration, which determine the shear rheology of the injected fluid, have been evaluated. Our findings show that the experimental pressure loss-flow rate data for inertial flow of shear-thinning fluids can be successfully predicted from the empirical parameters obtained during non-Darcian Newtonian flow and Darcian shear-thinning flow in a given porous medium. Fri, 01 Jan 2016 00:00:00 GMT http://hdl.handle.net/10985/15199 2016-01-01T00:00:00Z RADILLA, Giovanni RODRIGUEZ DE CASTRO, Antonio Understanding non-Darcian flow of shear-thinning fluids through rough-walled rock fractures is of vital importance in a number of industrial applications such as hydrogeology or petroleum engineering. Different laws are available to express the deviations from linear Darcy law due to inertial pressure losses. In particular, Darcy’s law is often extended through addition of quadratic and cubic terms weighted by two inertial coefficients depending on the strength of the inertia regime. The relations between the effective shear viscosity of the fluid and the apparent viscosity in porous media when inertial deviations are negligible were extensively studied in the past. However, only recent numerical works have investigated the superposition of both inertial and shear-thinning effects, finding that the same inertial coefficients obtained for non-Darcian Newtonian flow applied in the case of shear-thinning fluids. The objective of this work is to experimentally validate these results, extending their applicability to the case of rough-walled rock fractures. To do so, flow experiments with aqueous polymer solutions have been conducted using replicas of natural fractures, and the effects of polymer concentration, which determine the shear rheology of the injected fluid, have been evaluated. Our findings show that the experimental pressure loss-flow rate data for inertial flow of shear-thinning fluids can be successfully predicted from the empirical parameters obtained during non-Darcian Newtonian flow and Darcian shear-thinning flow in a given porous medium. http://hdl.handle.net/10985/20621 Application of Non-toxic Yield Stress Fluids Porosimetry Method and Pore-Network Modelling to Characterize the Pore Size Distribution of Packs of Spherical Beads RODRIGUEZ DE CASTRO, Antonio; AGNAOU, Mehrez; AHMADI-SENICHAULT, Azita; OMARI, Abdelaziz With X-ray computed tomography still being flawed as a result of limitations in terms of spatial resolution and cost, toxic mercury intrusion porosimetry (MIP) is nowadays the prevailing technique to determine PSDs of most porous media. Recently, yield stress fluids porosimetry method (YSM) has been identified as a promising clean alternative to MIP. This technique is based on the particular percolation patterns followed by yield stress fluids, which only flow through certain pores when injected at a given pressure gradient. In previous works, YSM was used to characterize natural and synthetic porous media, and the results were compared with MIP showing reasonable agreement. However, considerable uncertainty still remains regarding the characterized pore dimension with each method arising from the highly complex geometry of the interstices in real porous media. Therefore, a critical stage for the validation of YSM consists in achieving successful characterization of model porous media with well-known pore morphology and topology. With this objective in mind, a set of four packs of glass beads each with a given monodisperse bead size were characterized in the present work using different porosimetry methods: experimental YSM, numerically simulation of MIP and pore-network extraction from a 3D image. The results provided by these techniques were compared, allowing the identification of the pore dimensions being characterized in each case. The results of this research elucidate the causes of the discrepancies between the considered porosimetry methods and demonstrate the usefulness of the PSD provided by YSM when predicting flow in porous media. Tue, 01 Jan 2019 00:00:00 GMT http://hdl.handle.net/10985/20621 2019-01-01T00:00:00Z RODRIGUEZ DE CASTRO, Antonio AGNAOU, Mehrez AHMADI-SENICHAULT, Azita OMARI, Abdelaziz With X-ray computed tomography still being flawed as a result of limitations in terms of spatial resolution and cost, toxic mercury intrusion porosimetry (MIP) is nowadays the prevailing technique to determine PSDs of most porous media. Recently, yield stress fluids porosimetry method (YSM) has been identified as a promising clean alternative to MIP. This technique is based on the particular percolation patterns followed by yield stress fluids, which only flow through certain pores when injected at a given pressure gradient. In previous works, YSM was used to characterize natural and synthetic porous media, and the results were compared with MIP showing reasonable agreement. However, considerable uncertainty still remains regarding the characterized pore dimension with each method arising from the highly complex geometry of the interstices in real porous media. Therefore, a critical stage for the validation of YSM consists in achieving successful characterization of model porous media with well-known pore morphology and topology. With this objective in mind, a set of four packs of glass beads each with a given monodisperse bead size were characterized in the present work using different porosimetry methods: experimental YSM, numerically simulation of MIP and pore-network extraction from a 3D image. The results provided by these techniques were compared, allowing the identification of the pore dimensions being characterized in each case. The results of this research elucidate the causes of the discrepancies between the considered porosimetry methods and demonstrate the usefulness of the PSD provided by YSM when predicting flow in porous media. http://hdl.handle.net/10985/20695 Empirical Flow Rate/Pressure Drop Relationships for Capillaries of Triangular and Rectangular Cross-Sections to be Used in Yield Stress Fluid Porosimetry MACKAYA, Terence Emery; AHMADI-SENICHAULT, Azita; OMARI, Abdelaziz; RODRIGUEZ DE CASTRO, Antonio The aim of the present work is to investigate the flow rate/pressure gradient relationship for the flow of yield stress fluids through rectilinear capillaries of non-circular cross-sections. These capillaries very often serve as basic elements in the modeling of porous media as bundles of capillaries or pore-network models. Based on the notions of shape coefficient and critical Bingham number, empirical flow rate/pressure gradient relationships have been proposed for both Bingham and Herschel–Bulkley fluids. The reliability of these relationships has been assessed by performing numerical simulations with the open-source Computational Fluid Dynamics (CFD) package OpenFOAM. For the considered cross-sectional shapes (equilateral triangle and square), and for a wide range of Bingham numbers, the predictions of the proposed empirical relationships have shown to be in very good agreement with the results of the current numerical simulations, as well as with previous results from the literature. An interesting feature of the proposed empirical relationships is the possibility to easily predict the total flow rate under a given imposed pressure gradient in a bundle of non-circular capillaries having any random distribution of inscribed circle radii. Furthermore, in the context of the yield stress fluid porosimetry method (YSM), experimental data may now be processed based upon bundles of capillaries with non-circular cross-sections. Fri, 01 Jan 2021 00:00:00 GMT http://hdl.handle.net/10985/20695 2021-01-01T00:00:00Z MACKAYA, Terence Emery AHMADI-SENICHAULT, Azita OMARI, Abdelaziz RODRIGUEZ DE CASTRO, Antonio The aim of the present work is to investigate the flow rate/pressure gradient relationship for the flow of yield stress fluids through rectilinear capillaries of non-circular cross-sections. These capillaries very often serve as basic elements in the modeling of porous media as bundles of capillaries or pore-network models. Based on the notions of shape coefficient and critical Bingham number, empirical flow rate/pressure gradient relationships have been proposed for both Bingham and Herschel–Bulkley fluids. The reliability of these relationships has been assessed by performing numerical simulations with the open-source Computational Fluid Dynamics (CFD) package OpenFOAM. For the considered cross-sectional shapes (equilateral triangle and square), and for a wide range of Bingham numbers, the predictions of the proposed empirical relationships have shown to be in very good agreement with the results of the current numerical simulations, as well as with previous results from the literature. An interesting feature of the proposed empirical relationships is the possibility to easily predict the total flow rate under a given imposed pressure gradient in a bundle of non-circular capillaries having any random distribution of inscribed circle radii. Furthermore, in the context of the yield stress fluid porosimetry method (YSM), experimental data may now be processed based upon bundles of capillaries with non-circular cross-sections.