FEFLOW (Finite Element subsurface FLOW system) is a computer program for simulating

groundwater Groundwater is the water present beneath Earth's surface in rock and soil pore spaces and in the fractures of rock formations. About 30 percent of all readily available freshwater in the world is groundwater. A unit of rock or an unconsolidate ...

flow,

mass transfer Mass transfer is the net movement of mass from one location (usually meaning stream, phase, fraction or component) to another. Mass transfer occurs in many processes, such as absorption, evaporation, drying, precipitation, membrane filtration, ...

and

heat transfer Heat transfer is a discipline of thermal engineering that concerns the generation, use, conversion, and exchange of thermal energy (heat) between physical systems. Heat transfer is classified into various mechanisms, such as thermal conduction, ...

porous media A porous medium or a porous material is a material containing pores (voids). The skeletal portion of the material is often called the "matrix" or "frame". The pores are typically filled with a fluid (liquid or gas). The skeletal material is usu ...

and fractured media. The program uses

finite element analysis The finite element method (FEM) is a popular method for numerically solving differential equations arising in engineering and mathematical modeling. Typical problem areas of interest include the traditional fields of structural analysis, heat ...

to solve the

groundwater flow equation Used in hydrogeology, the groundwater flow equation is the mathematical relationship which is used to describe the flow of groundwater through an aquifer. The transient flow of groundwater is described by a form of the diffusion equation, similar to ...

of both saturated and unsaturated conditions as well as mass and heat transport, including

fluid In physics, a fluid is a liquid, gas, or other material that continuously deforms (''flows'') under an applied shear stress, or external force. They have zero shear modulus, or, in simpler terms, are substances which cannot resist any shear ...

density Density (volumetric mass density or specific mass) is the substance's mass per unit of volume. The symbol most often used for density is ''ρ'' (the lower case Greek letter rho), although the Latin letter ''D'' can also be used. Mathematical ...

effects and

chemical kinetics Chemical kinetics, also known as reaction kinetics, is the branch of physical chemistry that is concerned with understanding the rates of chemical reactions. It is to be contrasted with chemical thermodynamics, which deals with the direction in wh ...

for

multi-component reaction In chemistry, a multi-component reaction (or MCR), sometimes referred to as a "Multi-component Assembly Process" (or MCAP), is a chemical reaction where three or more compounds react to form a single product. By definition, multicomponent reaction ...

systems.

History

The software was firstly introduced by Hans-Jörg G. Diersch in 1979, se

and. He developed the software in the Institute of Mechanics of the

German Academy of Sciences Berlin The German Academy of Sciences at Berlin, german: Deutsche Akademie der Wissenschaften zu Berlin (DAW), in 1972 renamed the Academy of Sciences of the GDR (''Akademie der Wissenschaften der DDR (AdW)''), was the most eminent research institution ...

up to 1990. In 1990 he was one of the founders of WASY GmbH of

Berlin Berlin ( , ) is the capital and largest city of Germany by both area and population. Its 3.7 million inhabitants make it the European Union's most populous city, according to population within city limits. One of Germany's sixteen constitue ...

Germany Germany,, officially the Federal Republic of Germany, is a country in Central Europe. It is the second most populous country in Europe after Russia, and the most populous member state of the European Union. Germany is situated betwe ...

(the acronym WASY translates from German to ''Institute for Water Resources Planning and Systems Research''), where FEFLOW has been developed further, continuously improved and extended as a commercial simulation package. In 2007 the shares of WASY GmbH were purchased by DHI. The WASY company has been fused and FEFLOW became part of the DHI Group software portfolio. FEFLOW is being further developed at DHI by an international team. Software distribution and services are worldwide.

Technology

The program is offered in both

32-bit In computer architecture, 32-bit computing refers to computer systems with a processor, memory, and other major system components that operate on data in 32-bit units. Compared to smaller bit widths, 32-bit computers can perform large calculation ...

and

64-bit In computer architecture, 64-bit Integer (computer science), integers, memory addresses, or other Data (computing), data units are those that are 64 bits wide. Also, 64-bit central processing unit, CPUs and arithmetic logic unit, ALUs are those ...

versions for

Microsoft Windows Windows is a group of several proprietary graphical operating system families developed and marketed by Microsoft. Each family caters to a certain sector of the computing industry. For example, Windows NT for consumers, Windows Server for serv ...

and

Linux Linux ( or ) is a family of open-source Unix-like operating systems based on the Linux kernel, an operating system kernel first released on September 17, 1991, by Linus Torvalds. Linux is typically packaged as a Linux distribution, which ...

operating systems. FEFLOW's theoretical basis is fully described in the comprehensive ''FEFLOW book''.Diersch, Hans-Jörg G., ''FEFLOW – Finite element modeling of flow, mass and heat transport in porous and fractured media'', Springer, 2014, Berlin Heidelberg, XXXV, 996p., , (eBook), doi:10.1007/978-3-642-38739-5. It covers a wide range of physical and computational issues in the field of porous/fractured-media modeling. The book starts with a more general theory for all relevant flow and transport phenomena on the basis of the

continuum mechanics Continuum mechanics is a branch of mechanics that deals with the mechanical behavior of materials modeled as a continuous mass rather than as discrete particles. The French mathematician Augustin-Louis Cauchy was the first to formulate such m ...

, systematically develops the basic framework for important classes of problems (e.g., multiphase/multispecies non-isothermal flow and transport phenomena, variably saturated

, free-surface

groundwater flow Groundwater is the water present beneath Earth's surface in rock and soil pore spaces and in the fractures of rock formations. About 30 percent of all readily available freshwater in the world is groundwater. A unit of rock or an unconsolidate ...

, aquifer-averaged equations, discrete feature elements), introduces

finite element methods The finite element method (FEM) is a popular method for numerically solving differential equations arising in engineering and mathematical modeling. Typical problem areas of interest include the traditional fields of structural analysis, heat ...

for solving the basic multidimensional balance equations, in detail discusses advanced numerical algorithms for the resulting nonlinear and linear problems, and completes with a number of

benchmark Benchmark may refer to: Business and economics * Benchmarking, evaluating performance within organizations * Benchmark price * Benchmark (crude oil), oil-specific practices Science and technology * Benchmark (surveying), a point of known elevati ...

s, applications and exercises to illustrate the different types of flow, mass and heat transport problems (e.g., subsurface flow and

seepage Soil mechanics is a branch of soil physics and applied mechanics that describes the behavior of soils. It differs from fluid mechanics and solid mechanics in the sense that soils consist of a heterogeneous mixture of fluids (usually air and wat ...

problems, unsaturated-saturated flow, advective-diffusion transport,

saltwater intrusion Saltwater intrusion is the movement of saline water into freshwater aquifers, which can lead to groundwater quality degradation, including drinking water sources, and other consequences. Saltwater intrusion can naturally occur in coastal aquifers ...

, geothermal and

thermohaline Thermohaline circulation (THC) is a part of the large-scale ocean circulation that is driven by global density gradients created by surface heat and freshwater fluxes. The adjective ''thermohaline'' derives from '' thermo-'' referring to tempe ...

flow).

Other groundwater simulators

MODFLOW MODFLOW is the U.S. Geological Survey modular finite-difference flow model, which is a computer code that solves the groundwater flow equation. The program is used by hydrogeologists to simulate the flow of groundwater through aquifers. The sou ...

Groundwater Modeling System GMS (Groundwater Modeling System) is water modeling application for building and simulating groundwater models from Aquaveo. It features 2D and 3D geostatistics, stratigraphic modeling and a unique conceptual model approach. Currently supported ...

* MARTHE *

HydroGeoSphere HydroGeoSphere (HGS) is a 3D control-volume finite element groundwater model, and is based on a rigorous conceptualization of the hydrologic system consisting of surface and subsurface flow regimes. The model is designed to take into account all ...

HYDRUS Hydrus is a small constellation in the deep southern sky. It was one of twelve constellations created by Petrus Plancius from the observations of Pieter Dirkszoon Keyser and Frederick de Houtman and it first appeared on a 35-cm (14 in) d ...

* PORFLOW * MicroFEM LT * OpenGeoSys * Leapfrog Hydro * ECLIPSE simulator with the H2O extension

Peer review

References

External links

*{{official website, www.feflow.com Finite element software Finite element software for Linux Hydrogeology software Scientific simulation software Software that uses Motif (software) Engineering software that uses Qt Geology software for Linux