The Boundary Element Method For Groundwater Flow

In this book the application of the boundary element method to the solution of the Laplace equation is examined. This equation is of fundamental importance in engineering and science as it describes different types of phenomena, inclu- ding the groundwater flow applications highlighted in this book. Special subjects such as numerical integration, subdi- visionof the domain into regions and other computational aspects are discussed in detail in the first chapters. To demonstrate the accuracy and efficiency of the boundary ele- ment method, results obtained when solving the Laplace equa- tion have been compared against known analytical solutions. Other chapters deal with problems such as steady and unstea- dy flow in addition to infiltration problems. The applica- tions demonstrate that the boundary element method provides a powerful solution technique which can be effectively ap- plied to solve this type of problem.

The finite element method (FEM) is one of those modern numerical methods whose rise and development was incited by the rapid development of computers. This method has found applications in all the technical disciplines as well as in the natural sciences.One of the most effective applications of the finite element method is its use for the solution of groundwater flow problems encountered in the design and maintenance of hydraulic structures and tailing dams, in soil mechanics, hydrology, hydrogeology and engineering geology.The stimuli to write this book came from the results obtained in the solution of practical problems connected both with the construction and maintenance of fill-type dams and tailing dams and the utilization of groundwater in Czechoslovakia, and on the other hand from the experience gained in teaching hydraulic structures theory at the Faculty of Civil Engineering of the Technical University of Prague. All the experience so far obtained shows markedly the advantages of the finite element method and the great possibilities of its further development as well as its considerable demands on the algorithmization, programming and use of computer possibilities. The reader will find an explanation of the fundamentals of the finite element method directed mainly toward isoparametric elements having an exceptional adaptability and numerical reliability. The finite element method application to groundwater flow concerns mainly two-dimensional problems, which occur most frequently in practice. Considerable attention is given to non-linear and non-stationary problems, which are most important in application.A computer program (based on the eight-noded isoparametric elements) is included and fully documented.The book will be useful to civil engineers, hydrogeologists and engineering geologists who need the finite element method as a solution tool for the complex problems encountered in engineering practice.

This volume contains edited papers from IABEM-90, the 1990 Symposium of the Interna tional Association for Boundary Element Methods (IABEM). As stated in the By-Laws of the Association, the purposes of IABEM are: 1. to promote the international exchange of technical information related to the devel opment and application of boundary-integral equation (BIE) formulations and their numerical implementation to problems in engineering and science, commonly referred to as the boundary element method (BEM); 2. to promote research and development activities for the advancement of boundary integral equation methods and boundary element solution algorithms; 3. to foster closer personal relationships within the BEM community of researchers. The objectives of the Symposium, in line with those of the Association, was to provide a forum where the two "souls" of the Association, i. e. , (i) mathematical foundations and numerical aspects, and (ii) engineering applications could be integrated. We believe that the first aspect has been neglected in too many of the BEM Symposia held in the past, which, with a few exceptions (notably, the IUTAM Symposia on the subject) have emphasized the practical aspects of the method. As a consequence, we have tried to give a stronger emphasis to the more theoretical issues: this is attested for instance, by the fact that the two general lectures were given by Prof. Gaetano Fichera, of the University of Rome "La Sapienza," and Prof.

The dramatic advances in the efficiency of digital computers during the past decade have provided hydrologists with a powerful tool for numerical modeling of groundwater systems. Introduction to Groundwater Modeling presents a broad, comprehensive overview of the fundamental concepts and applications of computerized groundwater modeling. The book covers both finite difference and finite element methods and includes practical sample programs that demonstrate theoretical points described in the text. Each chapter is followed by problems, notes, and references to additional information. This volume will be indispensable to students in introductory groundwater modeling courses as well as to groundwater professionals wishing to gain a complete introduction to this vital subject. Key Features * Systematic exposition of the basic ideas and results of Hilbert space theory and functional analysis * Great variety of applications that are not available in comparable books * Different approach to the Lebesgue integral, which makes the theory easier, more intuitive, and more accessible to undergraduate students

The editors have published a select group of full length papers on boundary element analysis (BEA) photographed from camera ready manuscripts. The articles have been prepared by some of the most distinguished and prolific individuals in this field. More than half of these articles have been submitted by authors that participated in an International Forum on Boundary Element Methods, in Melbourne Australia, in the Summer of 1991. However, this volume is not a conference proceedings, as these authors have expanded their accounts to chapter length, and/or have tailored their expositions more toward the style employed in archival journal publications. The authors that did not participate in the International Forum have also adhered to the above mentioned philosophy. This work contains a definitive representation of the significant capabilities and applications currently available or under investigation that fall under the general category of advanced boundary element analysis. With treatments of mechanical, thermal, fluid, and electromagnetic phenomena, this book should thus be of value to graduate students, practitioners, and researchers in engineering, mathematics, and the physical sciences wishing to obtain a broader perspective or remain current in these important areas of computational simulation.

The Boundary Element Methods (BEM) has become one of the most efficient tools for solving various kinds of problems in engineering science. The International Association for Boundary Element Methods (IABEM) was established in order to promote and facilitate the exchange of scientific ideas related to the theory and applications of boundary element methods. The aim of this symposium is to provide a forum for researchers in boundary element methods and boundary-integral formulations in general to present contemporary concepts and techniques leading to the advancement of capabilities and understanding of this com putational methodology. The topics covered in this symposium include mathematical and computational aspects, applications to solid mechanics, fluid mechanics, acoustics, electromagnetics, heat transfer, optimization, control, inverse problems and other interdisciplinary problems. Papers deal ing with the coupling of the boundary element method with other computational methods are also included. The editors hope that this volume presents some innovative techniques and useful knowl edge for the development of the boundary element methods. February, 1992 S. Kobayashi N. Nishimura Contents Abe, K.

Computational Methods in Subsurface Flow explores the application of all of the commonly encountered computational methods to subsurface problems. Among the problems considered in this book are groundwater flow and contaminant transport; moisture movement in variably saturated soils; land subsidence and similar flow and deformation processes in soil and rock mechanics; and oil and geothermal reservoir engineering. This book is organized into 10 chapters and begins with an introduction to partial differential and various solution approaches used in subsurface flow. The discussion then shifts to the fundamental theory of the finite element method, with emphasis on the Galerkin finite element method and how it can be used to solve a wide range of subsurface problems. The subjects treated range from simple problems of saturated groundwater flow to more complex ones of moisture movement and multiphase flow in petroleum reservoirs. The chapters that follow focus on fluid flow and mechanical deformation of conventional and fractured porous media; point and subdomain collocation techniques and the boundary element technique; and the applications of finite difference techniques to single- and multiphase flow and solute transport. The final chapter is devoted to other alternative numerical methods that are based on combinations of the standard finite difference approach and classical mathematics. This book is intended for senior undergraduate and graduate students in geoscience and engineering, as well as for professional groundwater hydrologists, engineers, and research scientists who want to solve or model subsurface problems using numerical techniques.