Marcel Moura

J. F. Brodin, P. A. Rikvold, M. Moura, R. Toussaint and K. J. Måløy, "Competing Gravitational and Viscous Effects in 3D Two-Phase Flow Investigated With a Table-Top Optical Scanner," Front. Phys. 10, 936915 (2022).

K. J. Måløy, M. Moura, A. Hansen, E. G. Flekkøy, and R. Toussaint, “Burst Dynamics, Upscaling and Dissipation of Slow Drainage in Porous Media,” Front. Phys. 9, 718 (2021).

M. Moura, K. J. Måløy, E. G. Flekkøy and R. Toussaint, “ Intermittent dynamics of slow drainage experiments in porous media: Characterization under different boundary conditions,” Front. Phys. 7, 217 (2020).

M. Moura, E. G. Flekkøy, K. J. Måløy, G, Schäfer and R. Toussaint, “Connectivity enhancement due to film flow in porous media,” Phys. Rev. Fluids 4, 094102 (2019).

E. G. Flekkøy, M. Moura and K. J. Måløy, “Dynamics of the fluctuating flying chain,” Front. Phys. 7, 187 (2019).

E. G. Flekkøy, M. Moura and K. J. Måløy, “Mechanisms of the flying chain fountain,” Front. Phys. 6, 84 (2018).

M. Moura, K. J. Måløy, E. G. Flekkøy and R. Toussaint, “Verification of a dynamic scaling for the pair correlation function during the slow drainage of a porous medium,” Phys. Rev. Lett. 119, 154503 (2017).

M. Moura, K. J. Måløy, and R. Toussaint, “Critical behavior in porous media flow,” EPL (Europhysics Letters) 118, 14004 (2017).

M. Moura, E.-A. Fiorentino, K. J. Måløy, G. Schäfer, and R. Toussaint, "Impact of sample geometry on the measurement of pressure-saturation curves: Experiments and simulations,” Water Resour. Res., 51 (2015).

G. L. Vasconcelos, M. N. Moura, and A. M. J. Schakel, “Vortex motion around a circular cylinder,” Phys. Fluids 23, 123601 (2011).

G. L. Vasconcelos and M. Moura, “Vortex motion around a circular cylinder above a plane,” Phys. Fluids 29, 083603 (2017).

M. N. Moura, and G. L. Vasconcelos, “Four-vortex motion around a circular cylinder,” Phys. Fluids 25, 073601 (2013).

M. N. Moura, and G. L. Vasconcelos, "Vortex flow around a circular cylinder near a plane," Rev. Cub. Fis., 29, 1E42-1E44 (2012).

• Kern, Vanessa R.; Moura, Marcel; Olsen, Pål E. S. & Carlson, Andreas (2026). Patterning surface textured plates with a viscoplastic fluid. Physical Review Fluids. 11(9). doi: 10.1103/1jz3-5j4d. Full text in Research Archive Show summary

  The deposition of a viscoplastic fluid onto a substrate can be achieved by moving apart two plates initially separated by a fluid-filled gap, where the footprint shape depends on the initiation of a fingering instability. Here, we present an approach for controlled deposition of a viscoplastic fluid by designing the macroscopic structure of the solid substrate. Through experiments in a lifted Hele-Shaw cell, we explore how slot, square, pyramid, and triangular patterns affect the dynamics of liquid deposition. The substrate structures directly control the symmetry and final shape of the deposited viscoplastic footprint, while having little systematic influence on the maximal normal adhesive force or on the force-gap scaling exponents once the total entrapped volume is accounted for through an effective initial gap. We develop a scaling description for the normal force of a Herschel–Bulkley fluid, showing that the measured force decay reflects a superposition of capillary, yield stress, and viscous contributions. For experiments producing stable patterning, the measured effective exponents are consistent with the theoretical range predicted by this model. Finally, we interpret the pattern-selection mechanism through a dynamical permeability analysis where the substrate texture creates an anisotropic permeability field whose angular maxima correlate with the preferred inward propagation directions of the invading air. Our results highlight a direct link between substrate geometry, interfacial dynamics, and the final deposited morphology, showing how millimetric deposition patterns can be programed using submillimetric surface structures.

• Tavakkoli, Omid; Bedeaux, Dick; Kjelstrup, Signe; Berg, Steffen; Moura, Marcel & Wang, Ying Da [Show all 8 contributors for this article] (2026). Emergence of Darcy's law and apparent violation of Onsager symmetry in multiphase transport. Physical Review E (PRE). ISSN 2470-0045. 114(1). doi: 10.1103/79nz-zp2f. Full text in Research Archive
• Linga, Gaute; Pierce, Kevin; Moura, Marcel; Mathiesen, Joachim; Renard, Francois & Borgne, Tanguy Le (2026). Dynamic multiphase flow triggers chaotic mixing in porous media. Proceedings of the National Academy of Sciences of the United States of America (PNAS). ISSN 0027-8424. 123(34). doi: 10.1073/pnas.2612884123. Full text in Research Archive
• Xu, Yao; Moura, Marcel; Flekkøy, Eirik Grude & Måløy, Knut Jørgen (2026). A comparison of different image analysis techniques for mapping spatiotemporal pH and carbon dissolution in density-driven convection of CO2 in water. Advances in Water Resources. ISSN 0309-1708. 212. doi: 10.1016/j.advwatres.2026.105296. Full text in Research Archive
• Moura, Marcel; Bedeaux, Dick; Armstrong, Ryan T. & Kjelstrup, Signe (2025). Fluctuation–dissipation theorems in porous media two-phase flow: statistical characterisation of saturation fluctuations and measurement of Onsager coefficients | Journal of Fluid Mechanics | Cambridge Core. Journal of Fluid Mechanics. ISSN 0022-1120. 1026. doi: 10.1017/jfm.2025.10987. Full text in Research Archive Show summary

  Fluctuation–dissipation theorems in porous media two-phase flow: statistical characterisation of saturation fluctuations and measurement of Onsager coefficients - Volume 1026

• Moura, Marcel; Bedeaux, Dick; Armstrong, Ryan T. & Kjelstrup, Signe (2025). Fluctuation–dissipation theorems in porous media two-phase flow: statistical characterisation of saturation fluctuations and measurement of Onsager coefficients. Journal of Fluid Mechanics. ISSN 0022-1120. 1026. doi: 10.1017/jfm.2025.10987. Full text in Research Archive Show summary

  We introduce a novel experimental approach for measuring Onsager coefficients in steady-state multiphase flow through porous media, leveraging the fluctuation–dissipation theorem to analyse saturation fluctuations. This method provides a new tool for probing transport properties in porous media, which could aid in the characterisation of key macroscopic coefficients such as relative permeability. The experimental set-up consists of a steady-state flow system in which two incompressible fluids are simultaneously injected into a modified Hele-Shaw cell, allowing direct visualisation of the dynamics through optical imaging. By computing the temporal correlations of saturation fluctuations, we extract Onsager coefficients that govern the coupling between phase fluxes. Additionally, we have performed a statistical analysis of the fluctuations in the derivative of saturation under different flow conditions. This analysis reveals that while the fluctuations follow Gaussian statistics up to 2–3 standard deviations, they exhibit heavy tails beyond this range. This work provides an experimental foundation for recent theoretical developments in the extention of non-equilibrium thermodynamics to multiphase porous media flows. By linking microscopic fluctuations to macroscopic transport behaviour, our approach offers a new perspective that may complement existing techniques in the study of multiphase flow, making it relevant to both statistical physics and the broader fluid mechanics community.

• Moura, Marcel; Kern, Vanessa Ruth; Måløy, Knut Jørgen; Carlson, Andreas & Flekkøy, Eirik Grude (2025). Droplet spreading in a wedge: a route to fluid rheology for power-law liquids. Soft Matter. ISSN 1744-683X. 21(36), p. 7014–7020. doi: 10.1039/d5sm00286a. Full text in Research Archive Show summary

  Measuring the rheology of liquids typically requires precise control over shear rates and stresses. Here, we describe an alternative route for predicting the characteristic features of a power-law fluid by simply observing the capillary spreading dynamics of viscous droplets in a wedge-shaped geometry. In this confined setting, capillary and viscous forces interact to produce a spreading dynamics described by anomalous diffusion, a process where the front position grows as a power-law in time with an exponent that differs from the value 1/2 found in classical diffusion. We derive a nonlinear diffusion equation that captures this behavior, and we show that the diffusion exponent is directly related to the rheological exponent of the fluid. We verify this relationship by using both experiments and simulations for different power-law fluids. As the predictions are independent from flow-specific details, this approach provides a robust tool for inferring rheological properties from the spreading dynamics.

• Lee, Sang Hyun; Moura, Marcel; Srivastava, Shreya; Santelli, Cara & Kang, Peter K. (2025). Filamentous fungi control multiphase flow and fluid distribution in porous media. Nature Physics. ISSN 1745-2473. doi: 10.1038/s41567-025-03020-6. Full text in Research Archive
• Brodin, Joachim Falck; Pierce, James Kevin; Reis, Paula Kozlowski Pitombeira; Rikvold, Per Arne; Moura, Marcel & Jankov, Mihailo [Show all 7 contributors for this article] (2025). Interface instability of two-phase flow in a three-dimensional porous medium. Physical Review Fluids. 10(6). doi: 10.1103/hm82-167x. Full text in Research Archive Show summary

  We present an experimental study of immiscible, two-phase fluid flow through a three-dimensional porous medium consisting of randomly packed, monodisperse glass spheres. Our experiments combine refractive-index matching and laser-induced fluorescence imaging to resolve the morphology and stability of the moving interface resulting from the injection of one fluid into another. The imposed injection rate sets a balance between gravitational and viscous forces, producing interface morphologies which range from unstable collections of tangled fingers at low rates to stable sheets at high rates. The image data are complemented by time-resolved pressure measurements. We develop a stability criterion for the fluid interface based on the analysis of the 3D images and the pressure data. This criterion involves the Darcy permeability in each of the two phases and the time derivative of the pressure drop across the medium. We observe that the relative permeability encountered by the invading fluid is modified by the imposed flow rate in our experiment, which impacts the two-phase flow dynamics. We show that, in addition to the balance between the relevant forces driving the dynamics, local regions of crystalline order in the beadpack (crystallites) affect the stability of the invading front. This work provides insights into how disorder on multiple length scales in porous media can interact with viscous, capillary, and gravitational forces to determine the stability and dynamics of immiscible fluid interfaces.

• Khobaib, Khobaib; Reis, Paula Kozlowski Pitombeira; Moura, Marcel; Toussaint, Renaud; Flekkøy, Eirik Grude & Måløy, Knut Jørgen (2025). Gravity stabilized drainage in porous media with controlled disorder. Physical Review Research (PRResearch). 7(2). doi: 10.1103/PhysRevResearch.7.023040. Full text in Research Archive Show summary

  This work presents an experimental, numerical, and theoretical investigation of slow drainage processes in porous media, focusing on systematic variations in pore-scale disorder. We examine a system comprising a monolayer of cylinders in a quasi-two-dimensional (2D) geometry, where the medium's disorder is controlled via a disorder parameter, 𝜀. By systematically altering 𝜀, we randomly shift the positions of the cylinders and analyze the resulting effects on the gravity stabilized invasion front. Our results show that increasing 𝜀 has a significant impact on the stable width of the invasion front, with this width scaling with the disorder parameter according to an exponent 𝛽=0.57, which closely matches the theoretical value predicted by percolation theory for 2D systems. Additionally, we derive a reciprocal relationship between the dimensionless fluctuation number and the disorder parameter 𝜀. Moreover, we find a correlation between the invasion front width and the size of trapped clusters in the system, and we explore how pore disorder affects the air saturation left behind the invasion front. Both our experimental and numerical findings exhibit exponent values that align with theoretical scaling predictions. This study advances the current understanding of multiphase flows in porous media by specifically addressing the influence of pore-scale disorder on the morphology of invasion fronts.

• Birgisson, Hilmar Yngvi; Xu, Yao; Moura, Marcel; Flekkøy, Eirik Grude & Måløy, Knut Jørgen (2025). Mapping dissolved carbon in space and time: An experimental technique for the measurement of pH and total carbon concentration in density driven convection of CO2 dissolved in water. Advances in Water Resources. ISSN 0309-1708. 198. doi: 10.1016/j.advwatres.2025.104916. Full text in Research Archive
• Reis, Paula Kozlowski Pitombeira; Linga, Gaute; Moura, Marcel; Rikvold, Per Arne; Toussaint, Renaud & Flekkøy, Eirik Grude [Show all 7 contributors for this article] (2025). Interaction between corner and bulk flows during drainage in granular porous media. Advances in Water Resources. ISSN 0309-1708. 198. doi: 10.1016/j.advwatres.2025.104914. Full text in Research Archive
• Heijkoop, Selwin; Rieder, David; Moura, Marcel; Rücker, Maja & Spurin, Catherine (2024). A Statistical Analysis of Fluid Interface Fluctuations: Exploring the Role of Viscosity Ratio. Entropy. 26(9). doi: 10.3390/e26090774. Full text in Research Archive Show summary

  Understanding multiphase flow through porous media is integral to geologic carbon storage or hydrogen storage. The current modelling framework assumes each fluid present in the subsurface flows in its own continuously connected pathway. The restriction in flow caused by the presence of another fluid is modelled using relative permeability functions. However, dynamic fluid interfaces have been observed in experimental data, and these are not accounted for in relative permeability functions. In this work, we explore the occurrence of fluid fluctuations in the context of sizes, locations, and frequencies by altering the viscosity ratio for two-phase flow. We see that the fluctuations alter the connectivity of the fluid phases, which, in turn, influences the relative permeability of the fluid phases present.

• Reis, Paula Kozlowski Pitombeira; Linga, Gaute; Moura, Marcel; Rikvold, Per Arne; Toussaint, Renaud & Flekkøy, Eirik Grude [Show all 7 contributors for this article] (2024). Interaction between corner and bulk flows during drainage in granular porous media. arXiv.org. ISSN 2331-8422. doi: 10.48550/arXiv.2409.05574. Full text in Research Archive
• Alfazazi, Umar; Bedeaux, Dick; Kjelstrup, Signe; Moura, Marcel; Ebadi, Mohammad & Mostaghimi, Peyman [Show all 8 contributors for this article] (2024). Interpreting pore-scale fluctuations: Predicting transport coefficients in multiphase flow through porous media using the Green-Kubo formulation - An experimental investigation. Physics of Fluids. ISSN 1070-6631. 36(3). doi: 10.1063/5.0185605. Full text in Research Archive Show summary

  Flow fluctuations that are commonly associated with multiphase flow in porous media are studied using concepts from non-equilibrium thermodynamic and statistical mechanics. We investigate how the Green–Kubo formulation of the fluctuation dissipation theorem can be used to predict the transport coefficient from the two-phase extension of Darcy's law. Flow rate-time series data are recorded at the millisecond timescale using a novel experimental setup that allows for the determination of flow fluctuation statistics. By using Green–Kubo relations, a transport coefficient is predicted based on the integrated autocorrelation function. Notably, this coefficient aligned closely with the total effective phase mobility computed using Darcy's equation for multiphase flow, particularly in scenarios where a linear relationship between flow rate and pressure gradient was observed. Our results open a new field of coefficient explorations where microscale fluctuations during multiphase flow are directly linked to macroscale parameters.

• Holtzman, Ran; Dentz, Marco; Moura, Marcel; Chubynsky, Mykyta V.; Planet, Ramon & Ortín, Jordi (2024). Emergence of dissipation and hysteresis from interactions among reversible, nondissipative units: The case of fluid-fluid interfaces. Physical Review Fluids. 9(6). doi: 10.1103/PhysRevFluids.9.064001. Full text in Research Archive Show summary

  We examine the nonequilibrium nature of two-phase fluid displacements in a quasi-two-dimensional medium (a model open fracture) in the presence of localized constrictions (“defects”) from a theoretical and numerical standpoint. Our analysis predicts the capillary energy dissipated in abrupt interfacial displacements (jumps) across defects, and relates it to the corresponding hysteresis cycle, e.g., in pressure-saturation. We distinguish between “weak” (reversible interface displacement, exhibiting no hysteresis and dissipation) and “strong” (irreversible) defects. We expose the emergence of dissipation and irreversibility caused by spatial interactions, mediated by interfacial tension, among otherwise weak defects. We exemplify this cooperative behavior for a pair of weak defects and establish a critical separation distance, analytically and numerically, verified by a proof-of-concept experiment.

• Brodin, Joachim Falck; Måløy, Knut Jørgen; Moura, Marcel & Rikvold, Per Arne (2023). Rising Invader. In Médici, Ezequiel F. & Otero, Alejandro D. (Ed.), Album of Porous Media. Springer. ISSN 9783031238000. p. 55–55. doi: 10.1007/978-3-031-23800-0_41. Full text in Research Archive
• Brodin, Joachim Falck; Rikvold, Per Arne; Moura, Marcel & Måløy, Knut Jørgen (2023). Invasion Pattern. In Médici, Ezequiel F. & Otero, Alejandro D. (Ed.), Album of Porous Media. Springer. ISSN 9783031238000. p. 59–59. doi: 10.1007/978-3-031-23800-0_45. Full text in Research Archive
• Reis, Paula Kozlowski Pitombeira; Moura, Marcel; Linga, Gaute; Rikvold, Per Arne; Toussaint, Renaud & Flekkøy, Eirik Grude [Show all 7 contributors for this article] (2023). A simplified pore-scale model for slow drainage including film-flow effects. Advances in Water Resources. ISSN 0309-1708. 182. doi: 10.1016/j.advwatres.2023.104580. Full text in Research Archive Show summary

  Liquid-filled corners and capillary bridges can establish networks connecting seemingly isolated clusters during drainage in porous media. Coupled with drainage through the bulk of pores and throats, the flow through these networks constitutes a secondary drainage mechanism that can significantly affect fluid configurations and residual saturations. In order to investigate the prevalence of this drainage mechanism, we propose a quasi-static pore-network model based on modifying the trapped-cluster-identification algorithm in an invasion-percolation model. With the modification, wetting-phase connectivity is provided by direct successions of pores and throats, represented by sites and bonds, as well as by chains of interconnected capillary bridges. The advancement of the fluid interface in the porous matrix is determined by the bonds’ invasion thresholds and local capillary pressure values, calculated taking into consideration gravitational effects. With the proposed model, experimentally verified phenomena related to slow drainage in granular porous media are reproduced, showing good qualitative agreement.

• Brodin, Joachim Falck; Moura, Marcel; Toussaint, Renaud; Måløy, Knut Jørgen & Rikvold, Per Arne (2022). Visualization by optical fluorescence of two-phase flow in a three-dimensional porous medium. Journal of Physics: Conference Series (JPCS). ISSN 1742-6588. 2241. doi: 10.1088/1742-6596/2241/1/012004. Full text in Research Archive Show summary

  Abstract Slow flow of a single fluid through a porous medium is well understood on a macroscopic level through Darcy’s law, a linear relation between flow rate and a combination of pressure differences, viscosity, and gravitational forces. Two-phase flow is complicated by the interface separating the fluids, but understanding of two-dimensional, two-phase flow has been obtained from experiments using transparent cells. In most three-dimensional media, however, visual observation is difficult. Here, we present preliminary results of experiments on a model medium consisting of randomly packed glass spheres, in which one fluorescent liquid invades another. By refractive index matching and scanning with a sheet-shaped laser beam, we obtain slices of the flow patterns, which we combine into three-dimensional pictures. We observe a compact region of invading fluid, surrounded by finger-like protrusions. The compact region becomes more dominant with increasing invader flow rate. The patterns are theoretically analyzed in terms of the interplay between gravitational, viscous, and capillary forces.

• Brodin, Joachim Falck; Rikvold, Per Arne; Moura, Marcel; Toussaint, Renaud & Måløy, Knut Jørgen (2022). Competing Gravitational and Viscous Effects in 3D Two-Phase Flow Investigated With a Table-Top Optical Scanner. Frontiers in Physics. 10. doi: 10.3389/fphy.2022.936915. Full text in Research Archive Show summary

  We present experiments and theory describing the transition from viscosity-stabilized flow to gravitationally unstable fingering for two-phase flow in a cubic box, filled with a synthetic porous medium. Observation is made possible by the use of our newly developed table-top 3D scanner based on optical index matching and laser-induced fluorescence, which is described in detail. In the experiment, a more dense, more viscous fluid injected at a fixed flow rate from a point source at the top of the flow cell displaces a less viscous, less dense fluid. We observe a stable invasion zone near the inlet, which increases in size with increasing flow rates, and presents initially a close to hemispherical shape. At later times, the invasion front transits to an unstable mode and a fingering flow regime. The transition occurs at a predicted critical radius, Rc, corresponding to the zero of the combined viscous and gravitational pressure gradient.

• Spurin, Catherine; Rücker, Maja; Moura, Marcel; Bultreys, Tom; Garfi, Gaetano & Berg, Steffen [Show all 8 contributors for this article] (2022). Red Noise in Steady-State Multiphase Flow in Porous Media. Water Resources Research. ISSN 0043-1397. 58. doi: 10.1029/2022WR031947. Full text in Research Archive
• Vincent-Dospital, Tom Yannick Yves; Moura, Marcel; Toussaint, Renaud & Måløy, Knut Jørgen (2022). Stable and unstable capillary fingering in porous media with a gradient in grain size. Communications Physics. 5(1). doi: 10.1038/s42005-022-01072-1. Full text in Research Archive Show summary

  Multiphase flows in complex porous networks occur in many natural processes and engineering applications. We present an analytical, experimental and numerical investigation of slow drainage in porous media that exhibit a gradient in grain size. We show that the effect of such structural gradient is similar to that of an external force field on the obtained drainage patterns, when it either stabilises or destabilises the invasion front. For instance, gravity can enhance or reverse the drainage pattern in graded porous media. In particular, we show that the width of stable drainage fronts scales both with the spatial gradient of the necessary pressure for pore invasion and with the local distribution of this (disordered) threshold. The scaling exponent results from percolation theory and is − 0.57 for 2D systems. Overall, introducing a dimensionless Fluctuation number, we propose a unifying theory for the up-scaling of dual immiscible fluid flows covering most classical scenarii.

• Eriksen, Fredrik Kvalheim; Moura, Marcel; Jankov, Mihailo; Turquet, Antoine Leo & Måløy, Knut Jørgen (2022). Transition from viscous fingers to compact displacement during unstable drainage in porous media. Physical Review Fluids. 7(1). doi: 10.1103/PhysRevFluids.7.013901. Full text in Research Archive Show summary

  We describe a crossover from the viscous fingering instability to a compact invasion regime during viscously unstable drainage of porous media, and we investigate the underlying mechanisms of this compact fluid displacement. The study is based on a series of drainage experiments in a radial porous Hele-Shaw cell where we systematically vary the viscosity of the defending (wetting) fluid and the overpressure of the invading (nonwetting) fluid to map out the resulting invasion structures as a function of viscosity ratio and injection pressure. We show that above a threshold of injection pressure and viscosity ratio a more stable and compact invasion structure emerges within the viscous fingering patterns, i.e., a roughly circular displacement with viscous fingers on the outside. The onset of the stable displacement is found to begin at a rather low viscosity ratio M between the invading and defending fluids, i.e., when M≥10−3 for injection pressures of 3–5 kPa. We find that the ratio between the length of the outer fingers and the size of the compact invasion scales with the viscosity ratio and approaches a more or less constant value during growth, resulting in structures with proportionate growth and larger compact invasions for higher viscosity ratios. As opposed to the viscous fingering instability, we describe rich ganglion dynamics within the compact invasion structures and show that the pressure gradient is not screened by the outer fingers.

• Måløy, Knut Jørgen; Moura, Marcel; Hansen, Alex; Flekkøy, Eirik Grude & Toussaint, Renaud (2021). Burst Dynamics, Upscaling and Dissipation of Slow Drainage in Porous Media. Frontiers in Physics. 9. doi: 10.3389/fphy.2021.796019. Full text in Research Archive Show summary

  We present a theoretical and experimental investigation of drainage in porous media. The study is limited to stabilized fluid fronts at moderate injection rates, but it takes into account capillary, viscous, and gravitational forces. In the theoretical framework presented, the work applied on the system, the energy dissipation, the final saturation and the width of the stabilized fluid front can all be calculated if we know the dimensionless fluctuation number, the wetting properties, the surface tension between the fluids, the fractal dimensions of the invading structure and its boundary, and the exponent describing the divergence of the correlation length in percolation. Furthermore, our theoretical description explains how the Haines jumps’ local activity and dissipation relate to dissipation on larger scales.

• Moura, Marcel; Måløy, Knut Jørgen; Flekkøy, Eirik Grude & Toussaint, Renaud (2020). Intermittent Dynamics of Slow Drainage Experiments in Porous Media: Characterization Under Different Boundary Conditions. Frontiers in Physics. 7. doi: 10.3389/fphy.2019.00217. Full text in Research Archive Show summary

  The intermittent dynamics of slow drainage flows in a porous medium is studied experimentally. This kind of two-phase flow is characterized by a rich burst activity and our setup allows us to characterize those bursts directly via images of the flow and pressure measurements. Two different boundary conditions were analyzed: controlled withdrawal rate (CWR) and controlled imposed pressure (CIP). We have characterized geometrical and statistical properties of the bursts from images and pressure measurements. We have shown that in spite of leading to similar final invasion patterns, some dynamical features of the invasion differ considerably between the CWR and CIP boundary conditions. In particular, their pressure signatures are very distinct, which then translates into very distinct features on the power spectrum density of the pressure signals. A fully integrable analytical framework is presented which successfully describes the scaling features of the power spectrum for the CIP case.

• Flekkøy, Eirik Grude; Moura, Marcel & Måløy, Knut Jørgen (2019). Dynamics of the Fluctuating Flying Chain. Frontiers in Physics. 7, p. 1–15. doi: 10.3389/fphy.2019.00187. Full text in Research Archive Show summary

  A chain which is made to flow from a container, forms a striking arch that rises well above the container top. This phenomenon is caused by the well known Mould effect and is explained by a supply of momentum from the container, causing an upwards kick. Here we introduce a theory that allows for dynamic fluctuations of the chain and compare with corresponding simulations and experiments. The predictions for the chain velocity and fountain height agree well with experiments. We also explore the underlying mechanism for this momentum transfer for different chain models and find that it depends subtly on the nature of the chain as well as on the container.

• Moura, Marcel; Flekkøy, Eirik Grude; Måløy, Knut Jørgen; Schäfer, Gerhard & Toussaint, Renaud (2019). Connectivity enhancement due to film flow in porous media. Physical Review Fluids. 4(9). doi: 10.1103/PhysRevFluids.4.094102. Full text in Research Archive Show summary

  We study the effects of connectivity enhancement due to film flow phenomena on the drainage of an artificial porous medium and the relative influence of gravity for such effects. The medium is initially fully saturated with a liquid (wetting phase), which is displaced by air (nonwetting phase). Our setup allows us to directly visualize the dynamics of the flow and, in particular, to pinpoint which pore invasion events are due to film flow phenomena. We have observed the formation of an active zone behind the liquid-air interface, inside which film flow drainage events are more likely to occur. Understanding the basic mechanisms of film flow in artificial porous media is of relevance for the analysis of real three-dimensional porous systems, in which gravity cannot be neglected and film flow is bound to be present.

View all works in NVA

• Reis, Paula Kozlowski Pitombeira; Moura, Marcel; Pierce, Kevin; Måløy, Knut Jørgen & Linga, Gaute (2026). Secondary imbibition in 2D porous media: The role of flow direction in trapping. Full text in Research Archive
• Lynnebakken, Hilde & Moura, Marcel (2026). Oljesøl truet bibliotekets underjordiske magasin. Da fant forskerne fram en sopp som kan få oljen løs. - Titan.uio.no. Titan.uio.no. Full text in Research Archive
• Lee, Sang Hyun; Moura, Marcel; Srivastava, Shreya; Santelli, Cara & Kang, Peter K. (2026). There's a mushroom in the network: Filamentous fungi control multiphase flow and fluid distribution in porous media. Full text in Research Archive
• Moura, Marcel; Brodin, Joachim Falck; Reis, Paula Kozlowski Pitombeira; Pierce, Kevin; Jankov, Mihailo & Rikvold, Per Arne [Show all 11 contributors for this article] (2026). From Thin Films to Stable Fronts: Tabletop Experimental Approaches to 2D and 3D Porous Media Flows. doi: https:/www.youtube.com/live/bSQ-sHK6FTU?si=W9_rbJ5BkyRPHP0m. Full text in Research Archive
• Moura, Marcel; Bedeaux, Dick; Armstrong, Ryan T. & Kjelstrup, Signe (2026). Transient and steady-state multiphase flow experiments: fluctuation analysis, and the measurement of the Onsager coefficients. Full text in Research Archive
• Moura, Marcel; Hansen, Alex; Flekkøy, Eirik Grude & Måløy, Knut Jørgen (2026). POROUS MATTER: PoreLab's sci-art adventures in Romania. Full text in Research Archive
• Moura, Marcel; Reis, Paula Kozlowski Pitombeira; Rikvold, Per Arne; Linga, Gaute; Flekkøy, Eirik Grude & Schäfer, Gerhard [Show all 8 contributors for this article] (2026). Thin Film Flow: Fluid Transport via Thin Liquid Films in Slow Porous Media Flows. Full text in Research Archive
• Kern, Vanessa Ruth; Moura, Marcel; Olsen, Pål Eivind & Carlson, Andreas (2026). Complex Fluids in confinement: instabilities in textured lifting Hele-Shaw cells. Full text in Research Archive
• Moura, Marcel; Lanza, Federico; Kern, Vanessa Ruth; Olsen, Pål Eivind; Carlson, Andreas & Måløy, Knut Jørgen [Show all 7 contributors for this article] (2026). Instabilities in textured lifted Hele-Shaw cells and bubbly flows in a pipe. Full text in Research Archive
• Moura, Marcel (2026). Experimental methods in porous media: A little bit of our experimental activity at PoreLab (and some simulations). Full text in Research Archive
• Kern, Vanessa Ruth; Moura, Marcel; Olsen, Pål Eivind & Carlson, Andreas (2026). Instabilities and Pattern Formation in Textured Lifting Hele-Shaw Cells with Viscoplastic Fluids. Full text in Research Archive
• Xu, Yao; Moura, Marcel; Flekkøy, Eirik Grude & Måløy, Knut Jørgen (2025). Quantification for density-driven convection of CO2 in water. Full text in Research Archive
• Alfazazi, Umar; Moura, Marcel; Wang, Ying Da; Bedeaux, Dick; Kjelstrup, Signe & Mostaghimi, Peyman [Show all 7 contributors for this article] (2025). Using the fluctuation-dissipation theorem to measure total phase mobility during fractional flow experiments. zenodo. doi: 10.5281/ZENODO.16814306. Full text in Research Archive
• Moura, Marcel; Reis, Paula Kozlowski Pitombeira; Rikvold, Per Arne; Linga, Gaute; Flekkøy, Eirik Grude & Schäfer, Gerhard [Show all 8 contributors for this article] (2025). Thin Film Flow: Fluid Transport via Thin Liquid Films in Slow Porous Media Flows. Full text in Research Archive
• Moura, Marcel; Kern, Vanessa Ruth; Olsen, Pål Eivind; Carlson, Andreas; Måløy, Knut Jørgen & Flekkøy, Eirik Grude (2025). Complex fluids in confinement: spreading in a wedge and instabilities in textured lifted Hele-Shaw cells. Full text in Research Archive
• Lee, Sang Hyun; Moura, Marcel; Srivastava, Shreya; Santelli, Cara & Kang, Peter K. (2025). There's a mushroom in the network: Filamentous fungi control multiphase flow and fluid distribution in porous media. Full text in Research Archive
• Moura, Marcel; Kern, Vanessa Ruth; Olsen, Pål Eivind; Carlson, Andreas; Måløy, Knut Jørgen & Flekkøy, Eirik Grude (2025). Fluidos complexos em confinamento: espalhamento em cunha e instabilidades em células de Hele-Shaw texturizadas. Full text in Research Archive
• Brodin, Joachim Falck; Moura, Marcel; Pierce, James Kevin; Reis, Paula Kozlowski Pitombeira; Rikvold, Per Arne & Jankov, Mihailo [Show all 7 contributors for this article] (2025). Experimental Investigation of Two-Phase Flow with a Table-Top Optical Scanner: Interface Instability in a Three-Dimensional Porous Medium. Full text in Research Archive
• Reis, Paula Kozlowski Pitombeira; Moura, Marcel; Linga, Gaute; Toussaint, Renaud; Rikvold, Per Arne & Flekkøy, Eirik Grude [Show all 7 contributors for this article] (2025). Modeling Gas-Liquid Drainage in Porous Media with Network Models. Full text in Research Archive
• Moura, Marcel (2024). Radio Romania Cultural: Art is a vehicle of communication between science and society. [Radio]. Timisoara, Romania. Full text in Research Archive
• Moura, Marcel; Hansen, Alex; Måløy, Knut Jørgen & Flekkøy, Eirik Grude (2024). POROUS MATTER: Our sci-art adventures in Romania. Full text in Research Archive
• Moura, Marcel; Kern, Vanessa Ruth; Carlson, Andreas; Måløy, Knut Jørgen & Flekkøy, Eirik Grude (2024). Linking anomalous diffusion and rheology for a droplet spreading in a corner: A rheometer for power-law liquids. Full text in Research Archive
• Moura, Marcel; Måløy, Knut Jørgen; Flekkøy, Eirik Grude; Brodin, Joachim Falck; Reis, Paula Kozlowski Pitombeira & Linga, Gaute [Show all 7 contributors for this article] (2024). A pool of two-phase flows experiments: films, bursts, patterns and avalanches. Full text in Research Archive
• Moura, Marcel; Måløy, Knut Jørgen; Flekkøy, Eirik Grude; Brodin, Joachim Falck; Reis, Paula Kozlowski Pitombeira & Linga, Gaute [Show all 7 contributors for this article] (2024). A little bit of our activity at PoreLab and Njord. Full text in Research Archive
• Moura, Marcel; Hansen, Alex; Flekkøy, Eirik Grude & Måløy, Knut Jørgen (2024). POROUS MATTER: PoreLab's sci-art adventures in Romania. Full text in Research Archive
• Moura, Marcel; Eriksen, Fredrik Kvalheim; Jankov, Mihailo; Turquet, Antoine Leo; Hansen, Alex & Måløy, Knut Jørgen (2024). Experiments on transient and steady-state flows in porous media: the transition from viscous fingers to compact displacement during unstable drainage flows. Full text in Research Archive
• Reis, Paula Kozlowski Pitombeira; Linga, Gaute; Moura, Marcel; Rikvold, Per Arne; Toussaint, Renaud & Flekkøy, Eirik Grude [Show all 7 contributors for this article] (2024). Investigation of liquid connectivity and drainage in granular porous media. Full text in Research Archive
• Reis, Paula Kozlowski Pitombeira; Linga, Gaute; Moura, Marcel; Rikvold, Per Arne; Toussaint, Renaud & Flekkøy, Eirik Grude [Show all 7 contributors for this article] (2024). Investigation of liquid connectivity and drainage in granular porous media. Full text in Research Archive
• Reis, Paula Kozlowski Pitombeira; Linga, Gaute; Moura, Marcel; Rikvold, Per Arne; Toussaint, Renaud & Flekkøy, Eirik Grude [Show all 7 contributors for this article] (2024). Network modeling of corner and bulk flows during drainage in granular porous media. Full text in Research Archive
• Moura, Marcel & Stoeac-Vlăduți, Mirela (2023). Porous Hypnosis 1. doi: https:/www.metaspatiu.art/porous-matter-void-fractions-in-materials-ideas-and-society/#exhibition-view. Full text in Research Archive
• Moura, Marcel & Stoeac-Vlăduți, Mirela (2023). All Roads Are Porous. doi: https:/www.metaspatiu.art/porous-matter-void-fractions-in-materials-ideas-and-society/#exhibition-view. Full text in Research Archive
• Moura, Marcel; Hansen, Alex & Stoeac-Vlăduți, Mirela (2023). POROUS MATTER. Void fractions in materials, ideas and society. doi: https:/porelab.no/porous-matter-void-fractions-in-materials-ideas-and-society/. Full text in Research Archive Show summary

  The exhibition “POROUS MATTER. Void fractions in materials, ideas and society” opened its door on September 15th , 2023, located at Politehnica University in Timisoara, Romania. The POROUS MATTER exhibition delves into the concept of “porous matter” and explores its implications in various contexts. Through an interdisciplinary approach that combines art, science and societal perspectives, the exhibition aims to shed light on the hidden beauty and deeper meaning of the “void fractions” in our world. The four artists from Romania and Norway – Floriama Cândea, Maria Castellanos, Cosmin Haias, Stahl Stenslie, together with four scientists – Florin Dragan (UPT), Alex Hansen (PoreLab), Liviu Marsavina (UPT), Marcel Moura (PoreLab) and the project’s curatorial team – Mirela Stoeac- Vlăduți (curator) and Loredana Nedelcu (assistant curator), examine through their works and perspectives the complex relationship between porous materials and the impact of their research on ideas and society as a whole. Through the contemporary art installations created, artistic and scientific experiments, the exhibition invites visitors to reflect on the multifaceted nature of empty fractions and their role in shaping our physical and conceptual environment.

• Moura, Marcel; Reis, Paula Kozlowski Pitombeira; Schäfer, Gerhard; Toussaint, Renaud; Flekkøy, Eirik Grude & Rikvold, Per Arne [Show all 7 contributors for this article] (2023). Thin film flow: fluid transport via thin liquid films in slow porous media flows. Full text in Research Archive
• Holtzman, Ran; Sandnes, Bjørnar; Moura, Marcel; Icardi, Matteo & Planet, Ramon (2023). Editorial: Nonequilibrium multiphase and reactive flows in porous and granular materials. Frontiers in water. doi: 10.3389/frwa.2023.1315909. Full text in Research Archive
• Brodin, Joachim Falck; Rikvold, Per Arne; Moura, Marcel; Pierce, James Kevin; Toussaint, Renaud & Måløy, Knut Jørgen (2023). Experimental investigation of two phase flow with a table top optical scanner: the competition between viscous and gravitational effects under different boundary conditions. Full text in Research Archive
• Khobaib, Khobaib; Reis, Paula Kozlowski Pitombeira; Jankov, Mihailo; Moura, Marcel & Måløy, Knut Jørgen (2023). Experimental studies of slow drainage in porous media: Effect of the randomness of the porous medium on the fluid flow. Full text in Research Archive
• Moura, Marcel (2023). Interview TV Teleuniversitatea. [TV]. Timisoara, Romania. Full text in Research Archive
• Reis, Paula Kozlowski Pitombeira; Moura, Marcel; Linga, Gaute; Rikvold, Per Arne; Flekkøy, Eirik Grude & Måløy, Knut Jørgen (2023). A simplified pore-scale model for drainage including film flow effects. Full text in Research Archive
• Reis, Paula Kozlowski Pitombeira; Moura, Marcel; Linga, Gaute; Rikvold, Per Arne; Flekkøy, Eirik Grude & Måløy, Knut Jørgen (2023). A modified-invasion-percolation model for drainage in quasi-2D porous media. Full text in Research Archive
• Reis, Paula Kozlowski Pitombeira; Moura, Marcel; Linga, Gaute; Rikvold, Per Arne; Flekkøy, Eirik Grude & Måløy, Knut Jørgen (2023). A simplified pore-scale model for slow drainage including film-flow effects. Full text in Research Archive
• Reis, Paula Kozlowski Pitombeira; Moura, Marcel; Linga, Gaute; Rikvold, Per Arne; Toussaint, Renaud & Flekkøy, Eirik Grude [Show all 7 contributors for this article] (2023). Numerical analysis of drainage in porous media using network models. Full text in Research Archive
• Holtzman, Ran; Sandnes, Bjørnar; Moura, Marcel; Icardi, Matteo & Planet, Ramon (2023). Editorial: Nonequilibrium multiphase and reactive flows in porous and granular materials. Frontiers in water. 5. doi: 10.3389/frwa.2023.1315909. Full text in Research Archive
• Kern, Vanessa Ruth; Olsen, Pål Eivind; Moura, Marcel & Carlson, Andreas (2023). Patterned plates mould the shape of yield-stress fluids in lifted Hele-Shaw cells. Full text in Research Archive Show summary

  As fluids displace one another in lifted Hele-Shaw cells, complex fingering patterns can emerge. Our understanding of such fingering instabilities in complex materials, such as yield-stress fluids, is still in its fledgling stage. Here we experimentally consider the finger growth dynamics of a yield-stress fluid displaced by air in a lifted Hele-Shaw cell confined by various groove patterned plates. As air displaces the yield-stress fluid, the emergent fingering pattern depends on the lifting speed, initial plate separation and plate texture. Interestingly, we find that the plate’s texture influences finger growth, even outside the regime of traditional unstable viscous fingering, which will be discussed.

• Moura, Marcel; Måløy, Knut Jørgen & Hansen, Alex (2023). Experiments on the motion of liquids and gases through porous materials. Full text in Research Archive
• Moura, Marcel (2023). Towards the measurement of entropy in porous media flows: our preliminary experimental attempts. Full text in Research Archive
• Pierce, James Kevin; Moura, Marcel & Linga, Gaute (2023). Chaotic mixing in two-dimensional unsteady porous media flow. Full text in Research Archive
• Pierce, James Kevin; Linga, Gaute & Moura, Marcel (2023). Hallmarks of chaotic mixing in two dimensional unsteady porous media flow. Full text in Research Archive
• Pierce, James Kevin; Linga, Gaute & Moura, Marcel (2023). Impact of the solid structure on solute mixing in porous media flow. Full text in Research Archive
• Moura, Marcel (2022). Drainage experiments in porous media: from viscous fingers to compact invasion to film flow. Full text in Research Archive
• Moura, Marcel; Eriksen, Fredrik Kvalheim; Jankov, Mihailo; Turquet, Antoine Leo & Måløy, Knut Jørgen (2022). Transition from viscous Fingers to compact displacement during unstable drainage in porous media. Full text in Research Archive
• Moura, Marcel; Eriksen, Fredrik Kvalheim; Jankov, Mihailo; Turquet, Antoine Léo & Måløy, Knut Jørgen (2022). Transition from viscous fingers to compact displacement during unstable drainage in porous media. Full text in Research Archive
• Moura, Marcel; Brodin, Joachim Falck; Måløy, Knut Jørgen; Rikvold, Per Arne; Flekkøy, Eirik Grude & Jankov, Mihailo [Show all 8 contributors for this article] (2022). Thin film flow: fluid transport and pollution spreading in porous media. Full text in Research Archive
• Moura, Marcel; Reis, Paula Kozlowski Pitombeira; Eriksen, Fredrik Kvalheim; Turquet, Antoine Léo; Flekkøy, Eirik Grude & Toussaint, Renaud [Show all 8 contributors for this article] (2022). Complexity: “More is Different” also in porous media flows. Full text in Research Archive
• Moura, Marcel; Vincent-Dospital, Tom Yannick Yves; Måløy, Knut Jørgen & Flekkøy, Eirik Grude (2022). Watching paint dry and the making of the non-Newtonian doughnut. Full text in Research Archive
• Moura, Marcel; Brodin, Joachim Falck; Måløy, Knut Jørgen; Flekkøy, Eirik Grude & Rikvold, Per Arne (2022). Capillary pumping – the spreading of pollution in porous media. Full text in Research Archive
• Moura, Marcel; Eriksen, Fredrik Kvalheim; Jankov, Mihailo; Turquet, Antoine Léo & Måløy, Knut Jørgen (2022). Transition from viscous fingers to compact displacement during unstable drainage in porous media. Full text in Research Archive
• Moura, Marcel; Vincent-Dospital, Tom Yannick Yves; Måløy, Knut Jørgen & Flekkøy, Eirik Grude (2022). Watching paint dry and the making of the non-Newtonian doughnut. Full text in Research Archive
• Reis, Paula Kozlowski Pitombeira; Moura, Marcel; Måløy, Knut Jørgen; Flekkøy, Eirik Grude & Rikvold, Per Arne (2022). Pore-scale modeling of film flow effects during gas-liquid drainage. Full text in Research Archive
• Moura, Marcel; Eriksen, Fredrik Kvalheim; Turquet, Antoine Leo; Flekkøy, Eirik Grude; Toussaint, Renaud & Jankov, Mihailo [Show all 7 contributors for this article] (2021). Complexity: “More is Different” also in porous media flows. Full text in Research Archive
• Moura, Marcel; Måløy, Knut Jørgen; Flekkøy, Eirik Grude & Toussaint, Renaud (2021). Coffee is for drinking, tea is for porous media science: intermittent burst dynamics in slow drainage experiments in porous media. Full text in Research Archive
• Moura, Marcel (2021). Slik lager du bedre kaffe med litt fysikk og litt botanikk. Full text in Research Archive
• Bjorå, Charlotte Sletten; Moura, Marcel & Lynnebakken, Hilde (2021). Slik lager du bedre kaffe med litt fysikk og litt botanikk. [Internet]. Titan.uio.no. Full text in Research Archive
• Moura, Marcel (2021). Formação de padrões, sistemas complexos e mecânica de fluidos em meios porosos: mais é diferente. Full text in Research Archive
• Måløy, Knut Jørgen; Brodin, Joachim Falck; Rikvold, Per Arne; Moura, Marcel; Toussaint, Renaud & Schaefer, Gerhard [Show all 7 contributors for this article] (2020). Drainage in porous media under influence of a gravitational field. Full text in Research Archive
• Moura, Marcel; Måløy, Knut Jørgen; Flekkøy, Eirik Grude; Schäfer, Gerhard & Toussaint, Renaud (2020). Thin film flow: fluid transport via thin liquid films in slow porous media flows. Full text in Research Archive
• Rikvold, Per Arne; Brodin, Joachim Falck; Moura, Marcel Nascimento de & Måløy, Knut Jørgen (2020). Visualization of Two-phase Flow in a Three-dimensional Porous Medium. Full text in Research Archive
• Rikvold, Per Arne; Brodin, Joachim Falck; Moura, Marcel Nascimento de & Måløy, Knut Jørgen (2020). Visualization of Two-phase Flow in a Three-dimensional Porous Medium. Full text in Research Archive
• Brodin, Joachim Falck; Måløy, Knut Jørgen; Moura, Marcel; Toussaint, Renaud & Rikvold, Per Arne (2020). An experimental study of the interplay between viscous, capillary and gravitational forces in two-phase flow in a three-dimensional porous medium. Full text in Research Archive Show summary

  We study the interplay between viscous, capillary and gravitational forces in two-phase flow in a threedimensional porous medium, with the use of an optical scanner based on index-matched medium and fluorescent fluids. A more viscous, denser, fluid is injected into a less viscous, less dense fluid in a 3D porous medium, comprised of randomly packed glass beads of uniform size. We tune the injection rate over 10 experiments. Experience from the 2D scenario suggests that with a slow injection rate capillary and gravitational forces will dominate, and we should observe an unstable displacement and fingering. Conversely, with a high injection rate, viscous forces will dominate, leading to a more stable displacement and a narrower invasion front. How do the 2D findings hold up in the 3D scenario? We confirm the qualitative findings from the 2D experiments and establish a clear regime change, from unstable to stable displacement. We seek to derive a dimensionless number to quantify the relevant balance of forces and consider this number in relation to the invasion pattern. We characterize the invasion by Minkowski-functionals and fractal dimensions and seek relations between the found geometries and the derived dimensionless numbers.

• Moura, Marcel (2020). Ta en kopp te og tenk på jordskjelv. [Internet]. Norway. Full text in Research Archive
• Moura, Marcel (2020). Our activity at PoreLab and how the passage of air through a facemask is a flow in porous media problem. [TV]. Brazil. Full text in Research Archive
• Moura, Marcel (2019). Clean-up operation of the Brazilian beaches affected by the 2019 oil spill: how scientific knowledge derived from previous environmental disasters can help in defining a plan of action. Full text in Research Archive
• Moura, Marcel (2019). Como limpar uma praia II. Jornal Vanguarda. Full text in Research Archive

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