Download or read book Stochastic Analysis of Contaminant Transport in Heterogeneous Structured Porous Media written by Hai Huang and published by . This book was released on 2001 with total page 486 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Diffusion in Random Fields written by Nicolae Suciu and published by Springer. This book was released on 2019-05-31 with total page 267 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents, in an accessible and self-consistent way, the theory of diffusion in random velocity fields, together with robust numerical simulation approaches. The focus is on transport processes in natural porous media, with applications to contaminant transport in groundwater. Starting from basic information on stochastic processes, more challenging issues are subsequently addressed, such as the correlation structure of the diffusion process in random fields, the relation between memory effects and ergodic properties, derivation and parameterizations of evolution equations for probability densities, and the relation between measurements and spatio-temporal upscaling. Written for readers with a background in applied mathematics, engineering, physics or geophysics, the book offers an essential basis for further research in the stochastic modeling of groundwater systems.
Download or read book Stochastic Analysis Of Flow And Solute Transport In Heterogeneous Porous Media Using Perturbation Approach written by and published by . This book was released on 2001 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Analysis of flow and solute transport problem in porous media are affected by uncertainty inbuilt both in boundary conditions and spatial variability in system parameters. The experimental investigation reveals that the parameters may vary in various scales by several orders. These affect the solute plume characteristics in field-scale problem and cause uncertainty in the prediction of concentration. The main focus of the present thesis is to analyze the probabilistic behavior of solute concentration in three dimensional(3-D) heterogeneous porous media. The framework for the probabilistic analysis has been developed using perturbation approach for both spectral based analytical and finite element based numerical method. The results of the probabilistic analysis are presented either in terms of solute plume characteristics or prediction uncertainty of the concentration. After providing a brief introduction on the role of stochastic analysis in subsurface hydrology in chapter 1, a detailed review of the literature is presented to establish the existing state-of-art in the research on the probabilistic analysis of flow and transport in simple and complex heterogeneous porous media in chapter 2. The literature review is mainly focused on the methods of solution of the stochastic differential equation. Perturbation based spectral method is often used for probabilistic analysis of flow and solute transport problem. Using this analytical method a nonlocal equation is solved to derive the expression of the spatial plume moments. The spatial plume moments represent the solute movement, spreading in an average sense. In chapter 3 of the present thesis, local dispersivity if also assumed to be random space function along with hydraulic conductivity. For various correlation coefficients of the random parameters, the results in terms of the field scale effective dispersivity are presented to demonstrate the effect of local dispersivity variation in space. The randomness of local.
Download or read book Groundwater Contaminant Transport written by F.B.J. Barends and published by Routledge. This book was released on 2017-07-12 with total page 313 pages. Available in PDF, EPUB and Kindle. Book excerpt: Impacts of developed tools of heterogenous characterization on the hydrodynamics of flow and the transport mechanisms are illustrated in this text through a series of extensive numerical simulations consisting of single and multiple-realizations (Monte Carlo method).
Download or read book Stochastic Analysis of Contaminant Transport written by and published by . This book was released on 1990 with total page 48 pages. Available in PDF, EPUB and Kindle. Book excerpt: A reliability approach for probabilistic modeling of one-dimensional non-reactive and reactive transport in porous media provides two important quantitative results: (1) an estimate of the probability that dimensionless concentration equals or exceeds some specified level and, (2) the sensitivity of the probabilistic outcome to likely changes in each uncertain variable. The reliability approach is particularly attractive because it can incorporate various marginal probability density functions (PDF) for any of the uncertain variables. In this work uncertain variables include: groundwater flow velocity, diffusion coefficient, dispersivity, distribution coefficient, porosity and bulk density. The primary objective is to examine how the probabilistic outcome is influenced by choice of marginal PDF, correlation and magnitude of uncertainty for the variables. Because little information exists concerning the statistical characteristics of these uncertain variables, the investigation assumes a wide range of PDF types and statistical values in order to identify and isolate the most critical issues for further study. Results indicate that, even for very slow mean velocity, the probability estimate for non-reactive transport is most sensitive to uncertain flow velocity. For practical analysis, it appears acceptable to treat dispersivity as a deterministic constant. For non-reactive transport, correlation between flow velocity and diffusion coefficient has a slight impact, but correlation among other combinations of uncertain variables is not important. 34 refs., 10 tabs.
Download or read book Subsurface Flow and Transport written by Gedeon Dagan and published by Cambridge University Press. This book was released on 1997-09-04 with total page 257 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book describes a major method in modelling the flow of water and transport of solutes in the subsurface, a subject of considerable interest in the exploitation and preservation of water resources. The stochastic approach allows the uncertainty which affects various properties and parameters to be incorporated in models of subsurface flow and transport. These much more realistic models are of greater use in, for example, modelling the transport and build-up of contaminants in groundwater. The volume is based on the second Kovacs Colloquium organised by the International Hydrological Programme (UNESCO) and the International Association of Hydrological Sciences. Fifteen leading scientists with international reputations review the latest developments in this area. The book is a valuable reference work for graduate students, research workers and professionals in government and public institutions, interested in hydrology, environmental issues, soil physics, petroleum engineering, geological engineering and applied mathematics.
Download or read book Stochastic Analysis of Contaminant Transport written by and published by . This book was released on 1992 with total page 9 pages. Available in PDF, EPUB and Kindle. Book excerpt: A reliability algorithm is used to develop probabilistic (stochastic) models or contaminant transport in porous media. The models are based on advective-dispersive transport equations, and utilize the reliability algorithm with existing one- and two-dimensional analytical and numerical solutions. Uncertain variables in the models include: groundwater flow velocity (or permeability in the numerical model), dispersivity, diffusion coefficient, bulk density, porosity, and solute distribution coefficient. Each uncertain variable is assigned a mean, covariance, and marginal distribution. The models yield an estimate of the probability that the contaminant concentration will equal or exceed a target concentration at a selected location and time. The models also yield probabilistic sensitivity measures which identify those uncertain variables with most influence on the probabilistic outcome. The objective of this study is to examine the basic behavior and develop general conclusions regarding transport under certain conditions as modeled using a reliability approach.
Download or read book American Doctoral Dissertations written by and published by . This book was released on 2002 with total page 776 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Diffusion in Natural Porous Media written by Peter Grathwohl and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 198 pages. Available in PDF, EPUB and Kindle. Book excerpt: Diffusion in Natural Porous Media: Contaminant Transport, Sorption/Desorption and Dissolution Kinetics introduces the general principles of diffusion in the subsurface environment and discusses the implications for the fate and transport of contaminants in soils and groundwater. Emphasis is placed on sorption/desorption and the dissolution kinetics of organic contaminants, both of which are limited by the slow speed of molecular diffusion. Diffusion in Natural Porous Media: Contaminant Transport, Sorption/Desorption and Dissolution Kinetics compiles methods for calculating the diffusion coefficients of organic compounds (in aqueous solution or vapor phase) in natural porous media. The author uses analytical solutions of Fick's 2nd law and some simple numerical models to model diffusive transport under various initial and boundary conditions. A number of these models may be solved using spreadsheets. The book examines sorption/desorption rates of organic compounds in various soils and aquifer materials, and also examines the dissolution kinetics of nonaqueous phase liquids in aquifers, in both the trapped residual phase and in pools. Diffusion in Natural Porous Media: Contaminant Transport, Sorption/Desorption and Dissolution Kinetics concludes with a discussion of the impact of slow diffusion processes on soil and groundwater decontamination and the implications of these processes for groundwater risk assessment.
Download or read book Dissertation Abstracts International written by and published by . This book was released on 2005 with total page 842 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Stochastic Modeling of Macrodispersion in Unsaturated Heterogeneous Porous Media written by and published by . This book was released on 1992 with total page 19 pages. Available in PDF, EPUB and Kindle. Book excerpt: The objectives of the proposed study are: (1) to investigate factors controlling the fate and transport of contaminants in heterogeneous unsaturated soils, and (2) to develop a computationally feasible methodology for predicting chemical movements in large-scale unsaturated zone. The proposed study will provide ways to estimate uncertainties in chemical transport due to spatial variability of soil hydrologic parameters. The uncertainty analysis is essential to interpretation of any field experiment of transport of chemically reactive tracers. Without eliminating the uncertainty due to heterogeneity in hydrologic parameters, mechanisms and principles controlling chemical behaviors of contaminants in the field condition may be misinterpreted.
Download or read book Stochastic Analysis of Contaminant Transport Final Report July 1 1989 November 1 1991 written by and published by . This book was released on 1992 with total page 9 pages. Available in PDF, EPUB and Kindle. Book excerpt: A reliability algorithm is used to develop probabilistic (stochastic) models or contaminant transport in porous media. The models are based on advective-dispersive transport equations, and utilize the reliability algorithm with existing one- and two-dimensional analytical and numerical solutions. Uncertain variables in the models include: groundwater flow velocity (or permeability in the numerical model), dispersivity, diffusion coefficient, bulk density, porosity, and solute distribution coefficient. Each uncertain variable is assigned a mean, covariance, and marginal distribution. The models yield an estimate of the probability that the contaminant concentration will equal or exceed a target concentration at a selected location and time. The models also yield probabilistic sensitivity measures which identify those uncertain variables with most influence on the probabilistic outcome. The objective of this study is to examine the basic behavior and develop general conclusions regarding transport under certain conditions as modeled using a reliability approach.
Download or read book Scale Effect of Contaminant Transport in Saturated Porous Media Identified by the Time Fractional Advection dispersion Equation written by Rhiannon Maire Garrard and published by . This book was released on 2017 with total page 55 pages. Available in PDF, EPUB and Kindle. Book excerpt: Time nonlocal transport models such as the time fractional advection-dispersion equation (t-fADE) were proposed to capture well-documented non-Fickian dynamics for conservative solutes transport in heterogeneous media, with the underlying assumption that the time nonlocality (which means that the current concentration change is affected by previous concentration load) embedded in the physical models can release the effective dispersion coefficient from scale dependency. This assumption however has never been systematically examined using real data. This study fills this historical knowledge gap by capturing non-Fickian transport (likely due to solute retention) documented in literature (Huang et al. 1995) and observed in our laboratory from small to intermediate spatial scale using the promising, tempered t-fADE model. Fitting exercises show that the effective dispersion coefficient in the t-fADE, although differing subtly from the dispersion coefficient in the standard advection-dispersion equation, increases nonlinearly with the travel distance (varying from 0.5 to 12 m) for both heterogeneous and macroscopically homogeneous sand columns. Further analysis reveals that, while solute retention in relatively immobile zones can be efficiently captured by the time nonlocal parameters in the t-fADE, the retention-independent solute movement in the mobile zone is affected by the spatial evolution of local velocities in the host medium, resulting in a scale-dependent dispersion coefficient. The same result may be found for the other standard time nonlocal transport models, such as the well-known multi-rate mass transfer (MRMT) model and the hydrologic version of continuous time random walk (CTRW), that separate solute retention and jumps (i.e., displacement). Therefore, the t-fADE with a constant dispersion coefficient cannot capture scale-dependent dispersion in saturated porous media, challenging the application for stochastic hydrogeology methods in quantifying real-world, pre-asymptotic transport. Hence, improvements on time nonlocal models using, for example the novel subordination approach, are necessary to incorporate the spatial evolution of local velocities without adding cumbersome parameters. Future improvements are also explored, given knowledge obtained in this study.
Download or read book An Experimental Study of Contaminant Transport in Heterogeneous Porous Media written by Fengteng Chang and published by . This book was released on 1988 with total page 146 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Stochastic Models for Flow and Transport in Heterogeneous Porous Media written by Amir Hossein Delgoshaie and published by . This book was released on 2018 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Modeling flow and transport in porous media is an important part of the decision-making process in managing crucial resources such as underground aquifers and hydrocarbon reservoirs, subsurface disposal of contaminants, and the design of battery systems. The multiscale nature of porous media, the heterogeneity of their properties and the uncertainty of our knowledge of these properties pose significant modeling challenges that have been the focus of extensive research. In this work, four important contributions are made to the modeling of flow and transport in porous systems. First, a non-local formulation is rigorously derived to find the average flow solution in multiscale porous media. Second, the stochastic representation of the flow problem is used for quantifying the flow uncertainty in cases with heterogeneous conductivity fields. An algorithm is proposed for using the Feynman-Kac formulation for one-dimensional elliptic problems with piecewise constant conductivity and various schemes were explored to improve the efficiency of particle tracking algorithms for both stochastic and deterministic flow problems. The third contribution of this work is the introduction of the stencil method, a discrete temporal Markov model for modeling transport in networks representing porous material. The stencil method simplifies the temporal models used to simulate mean transport in porous media. Finally, a fast discrete temporal Markov velocity process is introduced to simulate ensemble transport in highly heterogeneous continuum scale conductivity fields. This is the first stochastic model to simulate dispersion in high-variance conductivity fields for both Gaussian and exponential correlation structures.
Download or read book Theory Modeling and Field Investigation in Hydrogeology written by S. P. Neuman and published by Geological Society of America. This book was released on 2000-01-01 with total page 260 pages. Available in PDF, EPUB and Kindle. Book excerpt: The refereed and edited proceedings of the symposium Schlomo P. Neuman: Recent Advances After 30 Years of Exceptional Contributions to Well Hydraulics, Numerical Modeling, and Field Investigations, which was held in Tucson, Arizona, in October 1998. Among the topics are four decades of inverse problems in hydrogeology, a connected-network paradigm for the alluvial aquifer system, the influence of multi-scale structure in non-ergodic solute transport in heterogeneous porous media, the Gaussian analysis of one-dimensional unsaturated flow in randomly heterogeneous soils, and the type-curve interpretation of transient single-hole pneumatic injection tests in unsaturated fractured tuffs at the Apache Leap Research Site. Annotation copyrighted by Book News Inc., Portland, OR
Download or read book Stochastic Modeling of Macrodispersion in Unsaturated Heterogeneous Porous Media Semi annual Progress Report August 1 1991 February 1 1992 written by and published by . This book was released on 1992 with total page 19 pages. Available in PDF, EPUB and Kindle. Book excerpt: The objectives of the proposed study are: (1) to investigate factors controlling the fate and transport of contaminants in heterogeneous unsaturated soils, and (2) to develop a computationally feasible methodology for predicting chemical movements in large-scale unsaturated zone. The proposed study will provide ways to estimate uncertainties in chemical transport due to spatial variability of soil hydrologic parameters. The uncertainty analysis is essential to interpretation of any field experiment of transport of chemically reactive tracers. Without eliminating the uncertainty due to heterogeneity in hydrologic parameters, mechanisms and principles controlling chemical behaviors of contaminants in the field condition may be misinterpreted.
