Conventional macroscale two-phase flow equations for porous media (such as Darcy's law and Richards Equation) require a constitutive relation for capillary pressure (Pc). The capillary pressure relation significantly impacts the behavior and prediction of fluid flow in porous media, and needs to accurately characterize the capillary forces. In a typical laboratory experiment, a functional macroscopic

We upscale reactive mixing using effective dispersion coefficients to capture the combined effect of pore-scale heterogeneity and molecular diffusion on the evolution of the mixing interface between two initially segregated dissolved species. Effective dispersion coefficients are defined in terms of the average spatial variance of the solute distribution evolving from a pointlike injection, that is

We study the upscaling of pore-scale transport of passive solute in a carbonate rock sample. It is characterized by microporous regions displaying heterogeneous porosity distribution that are accessible due to diffusion only, and a strongly heterogeneous mobile pore space, characterized by a broad distribution of flow velocities. We observe breakthrough curves that are characterized by strong tailing

The intent of this paper is to provide both an introduction to the concepts of information theory, and to review how such concepts might be effectively applied in computing information reduction via upscaling methods. The concept of using scaling postulates to reduce the dimensionality or amount of information in a problem is a central idea in upscaling. In this paper, we present a number of introductory

Quasi-steady gravity currents propagating first on a horizontal and then up a sloping boundary are investigated by means of theoretical analysis and laboratory experiments. The bottom slope ranged from 0.18 to 1 and full- and partial-depth configurations were considered. The developed theoretical model, using the depth averaged momentum equation, provides new physical insight into the importance of

This study characterized and modeled heterogeneous surface wettability in sandstone and investigated the role of spatial heterogeneity and correlation length of surface wettability on relative permeability in a supercritical CO2 (scCO2)-brine-rock system. Understanding the role of wettability heterogeneity on relative permeability is essential to geological CO2 sequestration, oil and gas recovery,

The Smoothed Particle Hydrodynamics (SPH) method is used in this paper to simulate the transport process of coastal pollutant by solving the two-dimensional (2D) depth averaged advection-diffusion equation in Lagrangian framework. To avoid directly discretizing the second-order derivatives, the diffusion terms are decomposed into two first-order derivatives by introducing the diffusive flux. To verify

Catalytic membranes can degrade gaseous pollutants to clean gas via a catalytic reaction to achieve green emissions. A catalytic membrane is a three scale porous medium. Membranes used in catalytic filters usually have thickness centimeters or millimeters, and consist of active (washcoat) particles, inert material and microscale, micron size, pores. The washcoat particles are porous material with nanoscale

Multiphase flow in porous media is found in a variety of engineering problems, including in technologies focused on satisfying the energy needs of an expanding global population while minimizing the effects of human activity on climate change. The objective of this study is to provide a better understanding of the importance and interdependence of the wettability-altered fraction, the degree of wettability

Using micro-CT imaging and differential pressure measurements, we design a comparative study in which we simultaneously measure relative permeability and capillary pressure on the same reservoir sandstone sample under water-wet and mixed-wet conditions during steady-state waterflooding experiments. This allows us to isolate the impact of wettability on a pore-by-pore basis and its effect on the macroscopic

Pore-network representations of permeable media provide the framework for explicit simulation of capillary-driven immiscible displacement governed by invasion-percolation theory. The most demanding task of a pore-network flow simulation is the identification of trapped defending phase clusters at every displacement step, i.e. the phase connectivity problem. Instead of employing the conventional adjacency

In recent years, several approaches in the field of pollution source identification have been developed to identify the unknown pollution source parameters (PSP) of a river pollution incident. These approaches rely on monitoring data which have to be collected in the case of the pollution incident. Up until now, the influence of the often arbitrarily selected monitoring data on the identification results

Despite a longstanding interest in understanding the effects of rock fragments on soil hydraulic properties, physically-based models to describe the effective hydraulic conductivity of stony soils are still rare. The conductivity of stony soils is mostly described by simple scaling approaches, assuming impermeable rock fragments. We present a model based on the general effective medium (GEM) theory

This article shows how to consistently and accurately manage the Lagrangian formulation of chemical reaction equations coupled with the superficial velocity formalism introduced in the late 80s by Quintard and Whitaker. Lagrangian methods prove very helpful in problems in which transport effects are strong or dominant, but they need to be periodically put back in a regular lattice, a process called

This study presents the development, refinement, and application of a 3-D multiphase flow model for the simulation of tsunami propagation on land and its hydrodynamic force on a coastal building. The model is based on the Volume/Surface Integrated Average-based Multi-Moment Method (VSIAM3) with improved accuracy by adopting the temporary moment (TM) method to update the non-normal flow variables. A

Anthropogenic climate change has led to nonstationarity in hydrological data and their statistical characteristics. To consider nonstationarity in regional frequency analysis, several nonstationary index flood (NS-IF) methods comprising a time-dependent site-specific scaling factor or nonstationary regional growth curves have been suggested. However, these methods have limitations related to underestimation

Reservoirs have been widely used to regulate streamflow to meet both human and natural water requirements. This study applies a hidden Markov-decision tree (HM-DT) model to derive representative reservoir operation modules under various operation conditions (i.e., inflow, storage, as well as unknown factors) and their transitions (the dynamic change of operation rules) that reflect the impacts of seasonality

We use Approximate Bayesian Computation and the Kullback–Leibler divergence measure to quantify to what extent horizontal and vertical equivalent electrical conductivity time-series observed during tracer tests constrain the 2-D geostatistical parameters of multivariate Gaussian log-hydraulic conductivity fields. Considering a perfect and known relationship between salinity and electrical conductivity

Michaelis–Menten kinetics describe a broad range of physical, chemical, and biological processes. Since they are non-linear, spatial averaging of reaction kinetics is non-trivial, and it is not known how concentration gradients affect the global effective kinetics. Here, we use numerical simulations and theoretical developments to investigate the effective kinetics of diffusing solute pulses locally

In this paper we introduce a mathematical model of sediment entrainment due to bore-generated turbulence in a shallow water context. In this model, the entrainment is assumed to be proportional to the energy decay rate across a bore on a mobile bed. The energy decay rate across a bore on a mobile bed is derived analytically. This model is incorporated into the one dimensional morphodynamic model developed

Information on menisci dynamics and equilibrium contact angles, θe, is needed for modeling multiphase flow of fluids in geologic formations. The wettability of fracture faces is relevant to applications such as waterflooding in enhanced oil recovery and evaluation of caprock integrity for geologic carbon sequestration. We investigated the vertical capillary rise of air-water menisci on exposed fracture

Mangrove forests can significantly attenuate tsunami waves and thus play an important role in coastal protection. As a first approximation, the problem is modeled utilizing solitary waves impinging on emergent/submerged rigid cylinders. A three-dimensional (3-D) numerical model using cyclic boundary conditions was developed based on the IHFOAM solver to investigate the effects of wave nonlinearity

Understanding of the soil moisture movement process in the unsaturated zone is crucial for an accurate estimate of the rate of recharge to the aquifer. The goal of the present research is therefore to quantify the temporal variability of moisture movement through the unsaturated zone. A new framework for quantifying the temporal variability of soil moisture movement over a relatively large space scale

The predictions of two recent and two classical mathematical models are compared with experimentally measured three-phase relative permeabilities. Experimentally determined constitutive relationships in two-phase systems were used as model input parameters to numerically predict relative permeabilities (kr) in three-phase systems. Then the estimated results were compared with experimental three-phase

The biofilm plays an important role in NAPL bioremediation, natural attenuation and the flow behaviour of contaminant in porous media. Therefore, NAPL biodegradation in the presence of any bacteria in the porous media needs to be considered for more accurate prediction of contaminant remediation from the soil and groundwater. The complex interaction between the NAPL biodegradation/dissolution and physiochemical

A pore-network modeling approach is proposed to understand mineral dissolution regimes during reactive transport, as well as changes in porosity and permeability. The transport problem is implemented with full consideration of the mass balance of the solute in all pore spaces, including pore-bodies and throats. The changes in geometry of the pore network due to calcite dissolution are taken into account

An isobar generated by a line or point sink draining a confined semi-infinite aquifer is an analytic curve, to which a steady 2-D plane or axisymmetric Darcian flow converges. This sink may represent an excavation, ditch, or wadi on Earth, or a channel on Mars. The strength of the sink controls the form of the ditch depression: for 2-D flow, the shape of the isobar varies from a zero-depth channel

An analytical model is proposed in this study to describe transient drawdown induced by non-Darcian flow in a confined aquifer with a single well circulation groundwater heat pump system. The Izbash equation and a linearization method are employed to describe non-Darcian flow in the horizontal direction of a confined aquifer and to approximate the nonlinear term in the governing equation, respectively

We present empirical evidence of the impact of water markets on agricultural production. From 1954 to 2012, we compare the crop composition in counties of the Rio Grande water market with neighboring control counties before and after the establishment of the water market in 1971. What we find is consistent with water markets facilitating a shift from low- to high-value crops, or, in terms of our empirical

We rest on an Information Theory perspective and assess (i) the average information content and (i) the information shared between Darcy flux fields associated with fields of hydraulic conductivity (K) characterized by differing support (or measurement) scale. We treat hydraulic conductivity as a spatial random field, characterized by a given distribution and correlation structure. The latter is modeled

We introduce original sensitivity analysis metrics with the aim of assistingdiagnosis of the functioning of a given model. We do so by characterizing model-induced dependencies between a target model output and selected model input(s) through the associated bivariate copuladensity. The latter fully characterizes the dependencies between two random variables at any order (i.e., without being limited

We present an Eulerian stochastic advection–diffusion–reaction (SADR) model and use it to explain incomplete mixing typically observed in transport experiments with bimolecular reactions. Unlike traditional advection–dispersion–reaction (ADR) models, the SADR model describes mechanical and diffusive mixing as two separate processes. In the SADR model, mechanical mixing is driven by random advective

Image-based modelling of porous media to study the transport and reaction processes has become an essential tool. The availability of increasingly large image datasets at high resolution creates a need to develop algorithms that can process massive size images at a low computational cost. This study presents an efficient workflow to extract pore networks from large size porous domains using a watershed

In this paper, different pore network models to simulate single-phase flow in porous media are built and their accuracy is evaluated. In addition to the conventional pore network model (CPNM) which consists of regular pore bodies and throat bonds, three improved pore network models (IPNMs) are developed allowing to better describing the real pore and throat geometry. The first improved pore network

Safe and cost-effective design of infrastructures, such as dams, bridges, highways, often requires knowing the magnitude and frequency of peak floods. The Generalized Extreme Value distribution (GEV) prevailed in flood frequency analysis along with distributions comprising location, scale, and shape parameters. Here we explore alternative models and propose power-type models, having one scale and two

Water demands for power generation within the energy-water nexus focus on both consumptive and withdrawn water for thermoelectric power plant cooling. However, the consumptive-based approach of water footprinting is incongruent with withdrawn water. Grey water footprints of thermoelectric power plants associated with thermal pollution offer a proxy method to integrate the consumptive (blue) water footprint

Hydropower generation in the Hetch Hetchy Power System is strongly tied to snowmelt dynamics in the central Sierra Nevada and consequently is particularly financially vulnerable to changes in snowpack availability and timing. This study explores the Hetchy Hetchy Power System as a representative example from the broader class of financial risk management problems that hold promise in helping utilities

Urban pluvial flooding is a threatening natural hazard in urban areas all over the world, especially in recent years given its increasing frequency of occurrence. In order to prevent flood occurrence and mitigate the subsequent aftermath, urban water managers aim to predict precipitation characteristics, including peak intensity, arrival time and duration, so that they can further warn inhabitants

In this article we consider a two-phase flow model in a highly heterogeneous porous column. The porous column consists of homogeneous blocks, where the porosity and permeability vary from one block to the other. The flow direction is perpendicular to the layering of the porous column, and hence can be approximated by one-dimensional model equations. The periodic change in porosity and absolute permeability

Flood is one of the most catastrophic natural disasters in the United States, particularly in the Southeast states where hurricanes and tropical storms are most prevalent, causing billions of dollars in damage annually and significant losses of life and property. The Weather Research and Forecasting Hydrological model (WRF-Hydro) is a community-based hydrologic model designed to improve the skill of

Solving image-based pore-scale flow and transport in porous materials is a mainstream of fundamental and industrial research to reveal the pertinent physics in the field of hydrogeology, reservoir engineering, paper and filter engineering. This research discipline requires tremendous integration of multidisciplinary research areas of image processing, computational fluid modelling, and high-performance

A procedure combining experiments and deep learning is demonstrated to acquire pore-scale images of oil- and water-wet surfaces over a large field of view in microfluidic devices and to classify wettability based upon these pore scale images. Deep learning supplants the manual, time-consuming, error-prone investigation and categorization of such images. Image datasets were obtained by visualizing the

The morphodynamics of tidal marshes is investigated using a novel model (MarshMorpho2D) that couples 2D tidal dynamics, wave dynamics, mass-conserving sediment transport, edge erosion, pond dynamics, and marsh upland migration. By only changing tidal range, sediment supply, and RSLR rate, the model reproduces a great variety of spatial patterns in marsh loss. For all tidal ranges, an increase in RSLR

Estimation of the permeability tensor is crucial for many natural and industrial porous media applications. Homogenization provides a rigorous framework to calculate effective parameters from pore-scale images of a representative unit cell of the porous medium by solving a boundary value problem, also known as closure problem, subject to global constraints. However, the latter are hard to satisfy for

A series of micro-scale core-flooding experiments were conducted in a miniature water-wet Berea sandstone sample to examine how changes in the desaturation (water-displacing-oil) protocol impact the non-wetting phase recovery and to provide, to the best of our knowledge, the first pore-scale evidences of the associated displacement subtleties. We studied (i) the continuous displacement mode (CDM),

In this work we develop a multiscale model for flow and transport problem in CO2-enhanced coalbed methane recovery. The coalbed methane reservoir is characterized by two levels of porosity associated with nanopores in the matrix and cleat network. Mass conservation equations for fluid mixture (CH4 and CO2) in the matrix at the microscale are rigorously derived by using the formal homogenization technique

The effect of emergent stems on the transport of downstream floating particles (e.g., buoyant seeds) is explored theoretically and experimentally at moderate to high Reynolds number (Rd=2Ubas/υ>300) in an open channel, where Ub is the bulk velocity, as is stem radius, and ν is the kinematic viscosity. Longitudinal dispersion (Dl) of such seeds is shown to be given by Dl=Up3τ02η(1−η)/2/(S1+ητ0Up) thereby

Hydraulic barriers using either two or three injection wells are studied analytically to evaluate their performance on improving groundwater extraction in a coastal aquifer under the threat of seawater intrusion. The multiple well system is operated by extracting fresh groundwater through a landward well and partially reinjecting into the aquifer through two or three wells located parallel to the coastline