DHI-WASY SoftwareFinite Element Subsurface Flow & Transport Simulation System FEFLOW 6 ® Installation Guide & Demonstration Exercise Copyright notice: No part of this manual may be photocopied, reproduced, or translated without written permission of the developer and distributor DHI-WASY GmbH. Copyright © 2010 DHI-WASY GmbH Berlin – all rights reserved. DHI-WASY, FEFLOW and WGEO are registered trademarks of DHI-WASY GmbH. DHI-WASY GmbH Waltersdorfer Straße 105, 12526 Berlin, Germany Phone: +49-(0)30-67 99 98-0, Fax: +49-(0)30-67 99 98-99 E-Mail:
[email protected] Internet: www.feflow.info www.dhigroup.com 2 Contents I Installation Guide I.1 I.2 l.2.1 I.2.2 I.2.3 I.2.4 l.2.5 l.2.6 I.2.7 I.3 I.4 Introduction Installing FEFLOW (Windows) Introduction System recommendations FEFLOW Installation Demo Data Installation Installation of the X server Exceed 2006 Installation of the Network License Manager NetLM License installation Installing FEFLOW (Linux) Installation Packages 3 4 4 5 5 6 6 7 7 8 8 9 10 II.2 Getting Started II.2.1 II.2.2 II.3.1 II.3.2 II.3.3 II.3.4 Starting FEFLOW The FEFLOW 6 User Interface Maps and Model Bounds Supermesh Finite element-mesh Expansion to 3D 14 14 14 II.3 Geometry 15 15 16 19 21 II.4 II.5 II.5.1 II.5.2 II.5.3 Problem settings Model Parameters Initial conditions Boundary conditions Material properties 28 30 30 32 37 II.6 II.7 II.7.1 II.7.2 II.7.3 II.7.4 II.7.5 II.7.6 II.7.7 II.7.8 Simulation Flow Transport Model Problem settings Initial Conditions Boundary conditions Material properties Vertical resolution Reference data Simulation Run Postprocessing 39 42 42 44 45 46 46 48 49 50 II Demonstration Exercise II.1 Introduction II.1.1 II.1.2 II.1.3 II.1.4 II.1.5 About FEFLOW Scope and Structure Terms and Notations Requirements Model Scenario 11 11 11 11 12 12 13 FEFLOW 6 I Installation Guide I.1 Introduction The FEFLOW simulation package contains the following main programs along with additional software tools: FEFLOW for other Linux distributions may be available for download from the FEFLOW website www.feflow.info. If you need FEFLOW for another Linux distribution, please do not hesitate to contact us at
[email protected]! For evaluation purposes, it is possible to obtain a fully functional but time-limited license from DHIWASY, one of the DHI offices, or from your local FEFLOW distributor. FEFLOW® 6.0 Interactive finite-element simulation system for modeling 3D and 2D flow, mass and heat transport processes in groundwater and the vadose zone. FEFLOW is provided on DVD for the following platforms: 32-bit operating systems • Windows XP, Vista, 7, Server 2003, Server 2008 • Linux: CentOS 4.6 (RedHat family), OpenSUSE 11.0 (SUSE family), Ubuntu 8.04 (Debian family) 64-bit operating systems • Windows XP x64 Edition, Vista x64 Edition, 7 x64 Edition, Server 2003 x64 Edition, Server 2008 x64 Edition • Linux: CentOS 4.4 (RedHat family), OpenSUSE 11.0 (SUSE family), Ubuntu 8.04 (Debian family) FEFLOW® Viewer FEFLOW Viewer is free software for visualizing FEFLOW models and results and for postprocessing purposes. FEFLOW Viewer is installed with FEFLOW. WGEO® 6.0 WGEO® is a sophisticated georeferencing, geoimaging and coordinate transformation software developed by DHI-WASY GmbH. A license for WGEO® Basis and the flexible 7-parameter transformation comes with each FEFLOW license and is installed automatically. WGEO® is provided for the Windows platform. Installation Guide & Demonstration Exercise 4 I.2 Installing FEFLOW (Windows) 5 I.2.1 Introduction FEFLOW 6 Standard provides powerful state-ofthe-art editing and visualization tools for most kinds of applications. As some of the lesser used functionality for data input is not yet implemented in FEFLOW 6 Standard, FEFLOW 6 Classic is provided as a fallback. Convenient tools make it easy to switch between the two types of user interface. The FEFLOW 6 Classic requires an X server running on display number 10 for proper operation. DHIWASY recommends to use Hummingbird Exceed 2006 for this purpose, a customized version of which is available on the FEFLOW DVD. It may only be used in conjunction with FEFLOW. To run FEFLOW in single-seat mode, the DHI-WASY License Manager NetLM has to be installed locally. Only NetLM has to be installed on network license servers, distributing FEFLOW licenses to clients in the network. So a typical FEFLOW installation on a Windows operating system consists of four steps: • Installation of FEFLOW and additional programs • Installation of the demo data package • Installation of the X server Exceed 2006 (only needed for running FEFLOW 6 Classic) • Installation of the DHI-WASY license manager NetLM After inserting the DVD into the DVD drive, an overview of the DVD contents is shown automatically. If autostart is disabled, run Starter.exe from the windows directory on the DVD. The hyperlinks in the overview can be used to start the different parts of the FEFLOW installation, to view the documentation and example movies, and to install third-party software. FEFLOW is automatically installed as a 32 bit version on 32 bit systems, and as 32 and 64 bit versions on 64 bit operating systems. FEFLOW 6 I 2 System recommendations The following system specifications are recommended as a minimum configuration. In the License window.3 FEFLOW Installation Start the Windows Installer by clicking on the hyperlink FEFLOW Program Files.2. The memory requirements depend on the size and complexity of the actual model to be simulated. • 512 MB RAM • 450 MB of disk space • Screen resolution of 1280 x 1024 or higher for FEFLOW 6 Classic • Separate graphics card with up-to-date graphics driver 3. choose Demo for testing FEFLOW without a license. A Welcome screen appears first. 2. Installation Guide & Demonstration Exercise 6 . In the next step. I I. Click Next after each step to proceed to the next step. the License Agreement has to be accepted. Select Client if the license to be used is installed on a remote license server (Network License) and type in the name or IP number of the license server. Please read it carefully before proceeding with the installation.2. Choose Server if a Single Seat License is to be used or if the machine is intended to act as a license server for a Network License.Installation Guide I. 1. For specifying a different destination directory.0.2. Start the installation or go back to change the settings. I. 6.4 Demo Data Installation The demo data installation is started by clicking on the hyperlink FEFLOW Demo Data.2. Finish the installation by clicking Finish. I. we recommend to manually deinstall all previous versions of Exceed.4.5 Installation of the X server Exceed 2006 Before installing Hummingbird Exceed for FEFLOW. click Browse. Select the packages to install. The default installation location is C:\Program Files\WASY\FEFLOW 6. FEFLOW 6 I . 5. FEFLOW is installed. Details about the packages can be found on the right of the window and on page 10 of this booklet. 7 7. This may take several minutes. If the dongle is lost.2. The basic X server settings are customized for running FEFLOW. Installation Guide & Demonstration Exercise 8 . Make sure that the firewall allows (local) TCP/IP connections on port 1800.7 License installation This step can be skipped for working in Demo mode only. Installation on a Terminal Server). There is only one dongle for each copy of FEFLOW. Start the DHI-WASY License Administration tool by clicking on the WASY License Administration entry in the All Programs\WASY group of the Windows start menu.Installation Guide Start the installation by clicking on the corresponding hyperlink. the installation of Exceed 2006 has to be performed in a different way: Follow the procedure described in ConnectivityInstallation. Follow the instructions in the installation dialog.6 Installation of the Network License Manager NetLM Before installing the Network License Manager NetLM we recommend to deinstall all previous versions of NetLM. The installation is started by clicking on the hyperlink License Manager NetLM.2. The setup installs all parts of Exceed 2006 (version 11) required for running FEFLOW. it can only be replaced by purchasing a new license of FEFLOW! I. I Terminal Server installation On Terminal Server. located in the windows\exceed directory of the FEFLOW DVD. • Install the dongle (hardware lock) on the USB port or parallel port resp.pdf (Chapter 3. All license installations have to be done with administrator privileges. I. or insert the name or the IP number of the remote license manager. Check whether the number returned in the field HOSTID is identical to the number on the FEFLOW license sheet.0. The information has to be identical in all details.0 from the WASY program group or double click on the desktop icon to start FEFLOW. select Dongle license in the FEFLOW 6. If the installation was not successful. The license information can be pasted from the clipboard if the license has been received digitally. insert localhost if the dongle is installed locally. I. please note that you have to use “6. a HASP HL USB dongle is required. • Click OK to close the License Administration dialog. FEFLOW 6 I . 9 For the version. In this case remove all dongles except the DHIWASY dongle. • For a full installation. If you do not already have such a dongle.0x” because your license is valid for all sub-versions of FEFLOW 6. use rpm e ‘rpm -qa | grep ’^wasy-’‘ • Note that you may need root privileges to perform these commands.For the 64 bit version of FEFLOW. • Click Install. A message box indicates that the license has been successfully installed.rpm • For deinstalling all WASY packages. Please also make sure that the same license type as on the license sheet is selected: • Single seat license – FEFLOW can be run only on the computer the dongle is attached to. use the following command: rpm -i *.0 branch.3 Installing FEFLOW (Linux) • Browse to the linux directory on the DVD. In case that multiple dongles of the same brand are connected. • Network license – FEFLOW can be used on any computer connected to the license server via TCP/IP network (LAN or WAN/internet). • Browse to the sub directory corresponding to your Linux distribution. Clients need TCP/IP connection on port 1800 to have access to the license server. a HOSTID mismatch may occur. please contact your FEFLOW distributor or DHIWASY for a dongle exchange! • In the tree view on the left side. • Switch to the Licenses tab and enter the license information from the FEFLOW license sheet. check all the license information in comparison to the information provided on the license sheet. Using a Network License for FEFLOW. In the Hostname or IP address field. • Choose FEFLOW 6. Copy the selected section in the license document to the clipboard and use on the Paste license from clipboard button to insert all the license information at once. • Click Connect. the WASY License Manager can be installed on any computer within the network (LAN or WAN) without the complete FEFLOW installation. • WGEO help .data for the demonstration exercise • Tutorial . FEFLOW FEFLOW program files .online help system • German Transformations . I.Installation Guide WGEO Basis is licensed automatically with FEFLOW. • The following packages are available: Plot Assistant GIS-like software for producing plots with FEFLOW data. geoimaging and transformation software .WGEO icon on the Windows desktop I • Packages for installation can be selected during the first installation or by re-running the installation in Modify mode. In the demo data installation there are the following packages: • Examples .data for the tutorials (User Manual) • Benchmarks .a WGEO license is installed automatically.example models • Exercise .4 Installation Packages WGEO Georeferencing. • A description for each package is shown in the right part of the Select feature dialog of the installation by selecting one of the packages. If a license dialog show up.coordinate transformation routines for Germany (may require separate licensing) • Desktop shortcut icon .development kit for the open programming interface IFM (required for plug-in development) • Desktop shortcut icon . just click on Cancel.FEFLOW help system • Interface Manager SDK .required for running FEFLOW • Help .benchmark models Installation Guide & Demonstration Exercise 10 .WGEO icon on the Windows desktop Data Tools Scripts for data checking and format conversion. vertical or axisymmetric) • fluid density-coupled. FEFLOW is used worldwide as a high-end groundwater modeling tool at universities. simulation.II Demonstration Exercise II.1 About FEFLOW FEFLOW (Finite Element subsurface FLOW and transport system) is an interactive groundwater modeling system for • three-dimensional and two-dimensional • areal and cross-sectional (horizontal. FEFLOW is available for WINDOWS systems as well as for different Linux distributions. to model geothermal processes. FEFLOW can be efficiently used to describe the spatial and temporal distribution and reactions of groundwater contaminants. Since its first appearance in 1979 FEFLOW has been continuously extended and improved.1. or uncoupled • variably saturated • transient or steady state • flow. mass and heat transport • reactive multi-species transport in subsurface water resources with or without one or multiple free surfaces. one of the FEFLOW distributors. and post processing of a three-dimensional flow and transport model based on (simplyfied) real-world data. to plan and design remediation strategies and interception techniques. For additional information about FEFLOW please do not hesitate to contact your local DHI office. Sophisticated interfaces to GIS and CAD data as well as simple text formats are provided.1 Introduction II. It is consistently maintained and further developed by a team of experts at DHI-WASY. research institutes. or have a look at the FEFLOW web site http://www. and to assist in designing alternatives and effective monitoring schemes.1. The option to use and develop user-specific plugins via the programming interface (Interface Manager IFM) allows the addition of external code or even external programs to FEFLOW.2 Scope and Structure This exercise provides a step-by-step description of the setup. 11 II. to estimate the duration and travel times of chemical species in aquifers. FEFLOW 6 . showing the philosopy and handling of the FEFLOW user interface.info. government agencies and engineering companies. also thermohaline.feflow. DHI-WASY. boundary conditions and material properties • Import of GIS data and regionalization • Simulation run • Results visualization and post processing toolbar panel button input box for text or numbers switch toggle radio button checkbox All file names are printed in bold red. The demo data installation package is available on the FEFLOW DVD as well as on the FEFLOW web site for download. The icons refer to the kind of setting to be done: main menu context menu Installation Guide & Demonstration Exercise 12 . The exercise covers the following work steps: • Import of background maps • Definition of the basic model geometry • Generation of a 2D finite-element mesh • Expansion of the mesh to 3D • Setup of a steady-state flow and transient transport model. A license is not necessary to run this tutorial (FEFLOW can be run in demo mode). please install the FEFLOW software including the demo data package. or common literature should be consulted in parallel. map names are printed in red.1. the demo data files for FEFLOW have to be installed. The latest version of FEFLOW can be downloaded from the website www. They are intended to assist in relating the written description to the graphical information provided by FEFLOW. II. In addition to the verbal description of the required screen actions this exercise makes use of some icons. Thus the exercise does not have to be done in one step even in demo mode.4 Requirements If not already done. numbers to be input in bold green.info. These files are not necessarily ready to run in the simulator.if working with a license .the model can be saved. Therefore. All required files are available in the FEFLOW demo data.de). II II.Demonstration Exercise You can skip any of the steps in this exercise by loading already prepared files at certain stages.3 Terms and Notations For following the exercise. some background knowledge of groundwater modeling is required. The demonstration exercise is not intended as an introduction to groundwater modeling itself. In case of any problems or additional questions please do not hesitate to contact the FEFLOW technical support (support@dhi-wasy. The symbol indicates an intermediary stage where either a prepared file can be loaded to resume this exercise or . Keyboard keys are referenced in <italic> style.1.feflow. including initial conditions. The other possible source is an abandoned waste-disposal site further east. There are two potential sources of the contamination: The first are abandoned sewage fields close to a waste-water treatment plant located in an industrial area northeast of town. such as rivers and lakes. The northern part of the model area is primarily used for agriculture. in the southeast of Berlin. and to quantify the potential pollution. First.II.5 Model Scenario A fictitious contaminant has been detected near the small town of Friedrichshagen. The town is surrounded by many natural flow boundaries. An increasing concentration of nitrate can be observed in two water supply wells. In both parts. The lake Müggelsee can limit the model domain to the south. The hydrogeologic system contains two main aquifers separated by an aquitard. A three-dimensional groundwater flow and contaminant transport model is set up to evaluate the overall threat to groundwater quality. FEFLOW 6 II . The northern boundary is chosen along an east-west hydraulic contour line of groundwater level north of the two potential sources of the contamination. significant urbanized areas exist. There are two small rivers that run northsouth on either side of Friedrichshagen that can act as the eastern and western boundaries. the model domain needs to be defined. 13 The geology of the study area is comprised of Quaternary sediments.1. The top hydrostratigraphic unit is considered to be a sandy unconfined aquifer up to 7 meters thick. The second aquifer located below the clayey aquitard has an average thickness of approximately 30 meters. whereas the southern portion is dominated by forest. Germany. adding or hiding particular toolbars and panels by using Installation Guide & Demonstration Exercise The last type of user interface component relevant for the exercise are diagrams. the other parts of the interface can be customized.Demonstration Exercise II. There are four different types of view windows: Supermesh view. Such files are provided for this example so that the model setup can be interrupted and picked up again. Looking very similar to panels. respectively.1 Starting FEFLOW On Windows Systems • Start FEFLOW 6. View windows can be closed via the corresponding button in the view frame. they contain plots of time curves. and dialogs. 3D view and Cross-Section view. toolbars. Different kinds of tools are linked to the different view types. II On Linux Systems • Type feflow60q in a console window and press <Enter> . FEFLOW asks whether to start in demo mode. New view windows can be opened by selecting Window > New and choosing the respective view window type.2 Getting Started II. FESlice view.2. The toolbar or panel has to be added then. While the main menu is always visible. panels. Thus this exersice may require to access a function in a toolbar or panel that is not visible at that moment. If no FEFLOW license is available. Missing diagram windows can be added to the user interface by opening View > Diagram from 14 . and it does not allow to execute the simulation run. view windows.0 via the corresponding desktop icon or the startup menu entry. Specially prepared demo files coming with FEFLOW are an exception. Please keep in mind that not all panels and toolbars are displayed by default. View windows display a certain type of view on the model and its properties. The demo mode does not allow loading and saving of files with more than 500 nodes. II. the menu command View > Panels and View > Toolbars.2. and the simulation runs can be performed.2 FEFLOW 6 User Interface The user interface components are organized in a main menu. All necessary files for this exercise are provided with the FEFLOW Demo Data package and are located in the project folder demo/exercise/standard. After import.shp (the outline of the waste disposal site) • demo_wells.the menu and choosing the required diagram from the list. This can be done manually. Load all the following maps at once (by holding <Ctrl> on the keyboard) to ensure that FEFLOW uses the bounding box of all the maps to define the initial domain bounds. by default a new document is opened. 15 II. Click on Load map(s).1 Maps and Model Bounds When FEFLOW starts.shp (a polygon that denotes the outer model boundary) • sewage_fields.tif (a georeferenced raster image of the model area for better orientation) • model_area. A double click on the Geo-TIFF topography_rectified adds the georeferenced topographic map to the active Supermesh view window. or by loading georeferenced maps.3 Geometry II. FEFLOW 6 II . Last. sorted by their file type (see figure).shp (the positions of the wells) Some of these maps will also be used for model parameterization later on. The map files are found in the subdirectory import+export. but not least it might be worth to mention that all steps done in FEFLOW can be undone and redone via the corresponding toolbar buttons. the maps are listed in the Maps panel. There is no limit on the number of undo steps. A new document can also be File > created using the menu command New or the New button in the Standard toolbar. The first step of model setup is the definition of the Initial Domain Bounds. The particular map files that are needed now are: • topography_rectified.3.dxf (the footprint of the sewage fields as a polygon) • waste_disposal. 2 Supermesh In the simplest case. For more clarity. Double-click on all the Default layer entries to add the visualization layers of the shape files to the Supermesh view. Make sure that the other maps are visible. The topmost map is drawn on top. all other maps are ESRI shape files. Now have a closer look at a second panel.Demonstration Exercise Except for the map sewage-fields. each with a default map layer. the View Components panel. geometrical features such as the position of pumping wells. Installation Guide & Demonstration Exercise 16 . In addition. The drawing order of maps can be modified by dragging them with the mouse to another position in the tree (this might become necessary as the model area polygon may overlay the polygons of the mass sources). To switch a map on and off. This panel lists the components that are currently plotted in the active view window. lines and points specified in the supermesh can be used later on to assign boundary conditions or material properties. When having double-clicked on the maps in the Maps panel. the maps have been added to the tree in the View Components panel. the checkbox in front of the map name can be checked/unchecked.3. the polygons. These vector files occupy their own branch in the tree. II II. The topographic map has mainly been loaded for providing a regional context. the limits of areas with different properties or the courses of rivers can be included to be considered for the generation of the finite-element mesh. Additionally. Checking/unchecking the checkbox of an entire branch all the maps in this branch become visible/invisible at the same time. it can be switched off before starting with the following operations. the supermesh contains a definition of the outer model boundary. Outer boundary This polygon can be directly loaded from the map model_area. 17 Well locations The positions of the wells can be imported directly from a map as well. Thus a valid supermesh exists that would allow the generation of a finite-element mesh. FEFLOW 6 II . Open the context menu of the map demo_wells and choose Convert to > Supermesh Points. two more features are to be included in the supermesh for this example: the well locations and the areas of contamination sources. open the context menu of this map (with a right-click on the map name) and choose Convert to > Supermesh Polygons.As mentioned above. using the information in the map. The points immediately appear as red dots in the Supermesh view. a supermesh may contain three types of features: • polygons • lines • points At least one polygon has to be created to define the model area boundaries. The editing tools are found in the toolbar: Mesh Editor A first supermesh polygon is automatically generated. However. In the Maps panel. II exercise_fri1. By selecting the map waste_disposal from the dropdown list in the Mesh Editor toolbar and activating Snap to points.Demonstration Exercise Start with the eastern source of contamination (the former waste-disposal site). Here. As the contamination sources are located completely inside the model area. the initial polygon covering the entire model area is partitioned manually.smh Contamination sources The estimated source areas of the contaminations are to be represented in the supermesh by polygons. This tool allows to split an existing polygon along a polyline to be drawn. To avoid overlapping of polygons (which is not allowed at any editing stage). This allows for accurate digitizing. a snapping mode is employed for the geometrical information in the corresponding background map. The mouse cursor snaps to the exact position of the polygon map nodes when clicking close to them. The splitting has to start and end at an already existing polygon border (but not necessarily at already existing polygon nodes). Installation Guide & Demonstration Exercise 18 . Click on Split Polygons. it is used to separate the two areas of contamination sources from the existing polygon. two cuts are necessary when carving the new polygon from the existing one. or points can be selected by using the Select tool. Click Generate Mesh to start mesh generation. The position of a point can be corrected after a polygon or line has been finished by using the Move node tool to shift its position (the snapping mode can be used here as well). green arrows).smh 19 II. For the next step.Zooming functions can be used at any time. All necessary tools can be found in the Mesh Generator toolbar.3 Finite element-mesh Once the outer boundary and other geometrical constraints have been defined in the supermesh. move the mouse up/down). Use the Split Polygons tool to create polygon borders along its outline. The second cut completes the polygon by cutting along the missing part of the border of the outline of the waste disposal (see figure. The first cut starts on an arbitrary point on the model boundary. choose Gridbuilder. is created. First. In the same way as before the polygon for the sewage fields. the western source of contamination. exercise_fri2. select the map sewage_fields for snapping in the dropdown list in the Mesh Editor toolbar. Corrections Accidently created polygons. then going half-way around the contamination source and returning to the model boundary on the other side (see figure. red arrows). Pan by pressing and holding the mouse wheel and moving the mouse to any direction. FEFLOW 6 II . Press and hold the right mouse button. Misplaced nodes in polygons or lines can be removed during digitizing by going back to the last correct node of the feature and clicking on it. For this example. They can be deleted hitting <Del> on the keyboard.3. Also the mouse wheel may be used for zooming. lines. the finite-element mesh can be generated. one of the mesh generation algorithms provided by FEFLOW is chosen from the drop-down list in the Mesh Generator toolbar. An example supermesh setup for both the disposal site and the sewage fields is shown in the following figure. Consequently. As only the polygon borders adjacent to the contamination sources need refinement. showing a much finer discretization now. at the pumping wells steep hydraulic gradients are expected at the center of the well cone. the occurrence of high concentration gradients is likely. In the Mesh Generator toolbar. enter 6000 as the Total Number and hit Generate Mesh again. Click on Generator Properties to open the Generator Properties dialog. The finite-element mesh in the FE-Slice view is updated. Second. At their borders. special attention should be paid to the areas of the contamination sources. 20 . this operation is to be applied only to Selected polygon or line-addin edges. II Local refinement First. For our purpose. FEFLOW also provides the means to edit the desired relative mesh density on a polygon-by-polygon basis. fine discretization is necessary. A finer spatial resolution is required. depicting the resulting finite-element mesh. Activate the Supermesh view again so that the Mesh Generator and Supermesh toolbar become visible again. possibly requiring an even finer spatial resolution to avoid oscillations in the solution. A new FE-Slice view is automatically opened. especially for the simulation of contaminant transport. Installation Guide & Demonstration Exercise Activate the Polygon gradation option by checking the corresponding box and set a refinement level of 20 (the maximum). Switch to the Supermesh view again to see the Mesh Generation toolbar.Demonstration Exercise Besides refinement along polygon borders. this initially generated mesh does not seem to be appropriate. the mesh needs local refinement along the polygon outlines. re-open it by choosing Window > New > Supermesh View from the menu. too. To realistically represent these. If the view has been accidentally closed. To obtain a refinement around the well locations. mesh at the edges of the contamination sources and around the well locations is finer. exercise_fri3. The refinement pattern looks similar to the one in the figure where the Up to this point we have worked on the model seen in top view. FEFLOW 6 II .4 Expansion to 3D exercise_fri3. a 3D model consisting of several layers is set up. Starting from this 2D geometry.fem II. The sections marked for refinement are highlighted in green color. Leave the dialog by clicking on OK. not considering the vertical direction. activate the Point element gradation.smh Generate Mesh one last time and check Click the changes in the mesh. Polygon edges are selected or deselected for refinement by clicking on them or by dragging a box around them. Click Refinement Selection. Select all borders of the contamination sources in this way. the polygon borders that are to be refined are selected. Apply a refinement level of 5. the maps have been switched off in the View Components panel). The detailed elevations of the layer tops and bottoms is derived by an interpolation based on map data. 21 Next. The figure shows the result (for better visibility.3. This makes FEFLOW switch the model geometry to 3D. An upper aquifer is limited by the ground surface on top and by an aquitard at the bottom. there is danger that the slices would temporarily intersect during the slice-wise assignment of elevations. This underlying stratigraphic layer is assumed to be impervious and is not part of the simulation. underlain by a low permeable unit of unknown thickness. The other slices are placed below with a distance of 1 m each. The actual stratigraphic data are applied in a second step afterwards. In a first step. II FEFLOW distinguishes between layers and slices in 3D. The number of slices automatically changes to 3 + 1 = 4 . The interfaces between layers. the top slice has a spatially constant elevation of 0 m. With these default elevations that are close to the expected real-world elevations. FEFLOW does at no time allow an intersection of slices and thus Installation Guide & Demonstration Exercise 22 . the model containing 3 layers. Layers are three-dimensional bodies that typically represent geological formations like aquifers and aquitards. as well as the top and bottom model boundary are called slices. Increase this value to 3 and hit <Enter>. By default. Initial 3D Setup Open Edit > 3D Layer Configuration. A second aquifer is situated below the aquitard. In the upper left corner of the dialog. the numbers of layers and slices are defined.Demonstration Exercise For this example. a text field shows the current number of layers (1). three geological layers are considered for the model. It is not necessary to visualize the map in the view. For better visibility in print. Click on Ok to apply the settings and to exit the dialog. and Slice. Enter a value of -1000 m to the elevation of top slice input box and hit <Enter>. open the context menu of the map elevations with a right click and choose FEFLOW 6 exercise_fri4. or in spreadsheet software such as Microsoft Excel or Open Office Calc.would reject the data assignment. Elevation Data This raw geometry now has to be formed into its real shape by regionalizing elevation data from the map files. now containing 4 planar slices with a distance of 1 m each. and have been combined into a text file (extension dat. the file can be used as the basis for regionalization of elevations for all slices at once. Y. The elevations are given in meters ASL. in this case with the elevation. The basic data have been derived from a DEM and from borehole logs. Go to the Maps panel and use the context menu ( Add Map(s). The slices are now at elevations of -1000 m and below. Such a file can be edited in a text editor. As a next step. This view shows the actual 3D geometry of the model. the slices are moved temporarily to an elevation low enough to prevent any interference with the realworld data.. The 3D view background by default is set to black. Ele. Therefore. a 3D view automatically opens. After finishing the basic layer configuration of the 3D model.. Containing the target slice number as a point attribute. 23 The file has to be loaded as a map before its attribute data can be used as the basis for interpolation. the attribute values of the data file need to be associated with (linked to) their respective FEFLOW parameter. tab separated) with four columns: X.fem II . for all images in this exercise a white view background has been applied.) to add elevations. In order to do this.dat to the list of loaded maps. Installation Guide & Demonstration Exercise The new link carries all the properties that can be defined for the data transfer from the map to the mesh nodes. In this tree. In practical projects.g.dat file containing multiple columns. e.dat uses default column headers (X. Link to Parameter… For a *. shp when using GIS. Y). or . By default. FEFLOW only applies two-dimensional interpolation. Select the entry Ele with a mouse click.Demonstration Exercise In this exercise. it may be preferred to store basic data in one file type. open the Process Variables > Elevation branch and click on Elevation. these are automatically recognized by FEFLOW and no specific column binding is required. As elevations. Click on Add Link to establish a connection between the values in the relief map and the elevation data. FEFLOW expects elevation data to be in the unit meters.. a tree view contains all available FEFLOW parameters that can be associated with the data. which is correct in this case. To separate data for the different slices. different file types are used as data source at the different stages of modelling to show the number of options.double click on Elevation to set the link. On the right-hand side. Thus the Parameter Association dialog is directly opened. the available attributes of the map are listed. it is usually necessary to define the respective columns containing X and Y coordinates etc. select 24 . II On the left-hand side of the dialog.alternatively . the <Shift> button in combination with the mouse wheel also changes the stretch factor for the active 3D view. Elevation data assignment Click into the 3D view to bring it to front. choose the attribute Slice as Field containing slice number (see image). and zooming are easily performed using the mouse: • Left mouse button: rotate the model around its center of gravity • Center mouse button (mouse wheel): pan the model (left/right/up/down) exercise_fri6. From the dropdown menu for Data Regionalization Method in the lower part of the dialog. Alternatively. exercise_fri5. Only the three map points that are closest to a mesh node are used for the interpolation. In the next line.fem • Right mouse button: zoom (in/out) As the model has a rather small vertical extent compared to its horizontal dimensions. 25 This can be done in the Navigation panel.fem FEFLOW 6 II . Make sure to have the Rotate tool in the View toolbar activated. the (vertical) z-axis should be exaggerated. Rotation. choose the Akima method. • Over-/Under Shooting: 0. a regionalization method has to be applied. Click on OK to apply these settings and to close the dialog.Field containing slice number in Node/Slice Selection. Click on the tab Projection and move the slider bar upwards until you have achieved a convenient view on the 3D model. As the properties. panning. Thus the resulting values may not exceed the range of input values. set: • Interpolation type: Linear • Neighbors: 3. To transfer data from the points in the map to all the mesh nodes. . II • Click Put value in the Editor toolbar to apply the new elevation data to all nodes. > > Under Linked Attributes. Click on bar.Demonstration Exercise Additional selection options are described in detail in the FEFLOW help system. Probadly the Scaling has to be adjusted again ( Navigation panel > Projection tab or <Shift> mouse wheel) to account for the changed vertical extent. in the Editor toolbar. double-click on Ele -> Elevation. i. In the 3D view the node elevations are immediately updated. the map elevation is automatically set as data source in the input box and the model property Elevation is activated as parameter. Installation Guide & Demonstration Exercise 26 . two more steps are required: • In the Maps panel. open the branch Maps ASCII Tables elevation. Clear Selection in the Selection tool- The result looks as shown in the figure below. the target locations of the data assignment have to be defined. Click on Select All in the Selection toolbar.e. As a next step. all nodes in the mesh have to be selected. Note that also Elevation has been chosen in the Data panel and is now shown in bold letters. To finally assign the elevation data by regionalization from map data to the selected nodes. • Hereby. Reset the stretch factor in the Navigation panel to return to real elevations display. Go to the 3D view and double-click on the layer Default of sewage_plant. In the upcoming Map Properties dialog.fem 3D Maps As an example for a three-dimensional map.shp in the Maps panel via Add map(s). activate Draw 3D Data and click Apply Changes. Choose Edit Properties in the context menu of the Default layer. The footprint of the buildings and clarifiers is shown on top of the model somewhat north of the sewage fields. a simple representation of the sewage plant is loaded.Optionally use the other settings in the dialog to classify the features. FEFLOW 6 II . Add the map file sewage_plant. adjust colors and outline style. The structures are shown in 3D on the model top. 27 exercise_fri7. They are vertically exaggerated with the model. II Installation Guide & Demonstration Exercise 28 . FEFLOW provides the means to simulate a number of different physical processes in different spatial and temporal dimensions. unsaturated.Demonstration Exercise II. All these settings are organized in thematic pages controlled by a tree view on the left-hand side of the dialog. By default saturated media is selected. Keep the default setting (Saturated Media) for this exercise. As the input parameters depend on the model type.4 Problem settings Problem class The principal type of the FEFLOW model is defined on the Problem Class page. ranging from simple 2D steady-state flow models to transient. applying Darcy’s equation. In this particular case.would lead to Richards’ equation being applied. Though saturated media is selected. the general problem settings are done at the beginning. Go to Edit > Problem Settings to open the Problem Settings dialog. the model is able to account for phreatic conditions. being capable of accounting for both saturated and unsaturated conditions within one model. Below the Problem title (which is not mandatory to be modified) one of two general types of problems – saturated media and unsaturated/variably saturated media is chosen.unsaturated model . where all general settings related to the current model are done. it is not expected that considering the unsaturated/variably saturated zone in detail would change the model result to an extent that would justify the additional effort in parametrization and numerical effort for the solution. density-coupled reactive transport models. The second option . but switch to Steady Flow. For the slices 2 and 3 keep the option Unspecified. Hereby. In the Status column. switch to Unconfined aquifer(s). it is also possible to add solute or heat transport processes to the always executed flow simulation.fem 29 On the same page. In this configuration. Thus we first focus on the flow model and add mass transport at a later stage. so that they also can move if necessary. activating the transport option now would increase the complexity to an extent that is not necessary at this stage. the top slice of the mesh follows the possibly moving groundwater table. The settings for unconfined conditions are located on the Free Surface page. and slices 2 and 3 inherit its setting. Click on OK to apply the changes and close the dialog and confirm with Yes. exercise_fri8. FEFLOW 6 II . open the drop down list of Slice 1 and choose the option FREE & MOVABLE. so a phreatic water table is to be simulated. The flow model is set up for steady-state conditions. the top slice is handled as movable. For slice 4. keep the default Fixed. Besides choosing between transient and steadystate conditions. First of all. an approximation of the phreatic level by applying a moving-mesh technology is chosen. For more information on the handling of free surfaces in 3D models. For this example. please refer to the help system and FEFLOW White Papers. Click on Apply to apply the changes. Thus keep the default Flow Only.Free Surface The first aquifer in the simulation area is known to be unconfined. However. Problem class settings are done. e.5 Model Parameters In the following sections. Average groundwater levels derived from several observation wells are provided in a text file. These files can be prepared in a text editor or in spreadsheet software such as Microsoft Excel or Open Office Calc.. II II. The parameters are organized in four main branches in the tree view: • Process Variables • Boundary Conditions • Material Properties • Reference Data The file is provided in FEFLOW Triplet format. a simple ASCII (text) format containing point-based values in three columns (separated by tab or space).Demonstration Exercise II.. elevation). The workflow to assign initial hydraulic head corresponds to the one described in the previous section for elevations: demo_head_ini. i. in the context menu of the Maps panel • Link the only attribute column Value to the FEFLOW parameter Process Variables > Flow > Hydraulic head • For the regionalization method. choose Akima linear with 3 Neighbors and 0 % Over/Under Shooting as before. Inital conditions are set as process variables for the beginning of the simulation.trp: • Load the map Add Maps..5. The respective parameters are found in the Data panel. the third column the parameter value.1 Initial conditions For a transient simulation we need initial conditions as starting conditions at time zero of the simulation. Installation Guide & Demonstration Exercise 30 . The first two columns contain the global X and Y coordinates. the physical properties of the study area are applied to the finite-element model. a head distribution is shown in the view with colors representing heads around 32 m at the southern border and 46 m at the northern border. • Select all nodes at once by a single click on the Select All button in the Selection toolbar while having the 3D view active. exercise_fri9. A legend is shown in the upper left corner of the view.31 • Close the Parameter Association dialog by clicking on OK. • Click on Clear Selection.fem FEFLOW 6 II . • In the Maps panel double-click on Maps > ASCII Triplet Files > demo_head_ini > Linked attributes > Value -> Hydraulic head. As a result. • Click on Put value in the Editor toolbar to execute the interpolation and set the initial head values. The boundary conditions are not derived from a map (even though this would be possible). Browsing between the slices is easiest by hitting the <Pg Up> and <Pg Down> keys. the Selection toolbar provides additional tools for selecting nodes compared Installation Guide & Demonstration Exercise 32 . we assume these heavily clogged creeks to represent boundary streamlines. appropriate boundary conditions are applied. No exchange of water is expected over this boundary and therefore a no-flow boundary condition is assumed. they will be kept in a rather simple way: • Southern border: The lake Müggelsee completely controls the head along the southern boundary.Demonstration Exercise II. each with a pumping rate of 1. Thus switch to the FE-Slice view. For the sake of simplicity. a head contour line will be used instead (fixed head = 46 m).2 Boundary conditions As a next step.000 m³/d. For the FE-Slice view.5. • Finally. II FE-Slice view This view type always shows a single slice or layer. The mouse buttons are associated with the following functions: • Left and center mouse button: pan • Right mouse button: zoom (in/out) • Mouse wheel: zoom (in/out) in steps Northern Boundary Zoom to the northern boundary. are located in the southern part of the model. the layer/slice to be seen in the view can be directly selected in the Spatial Units panel. These stand for a number of large well galleries in reality. • Northern border: As there is no natural boundary condition like a water divide close to the boundary. • Western and eastern border: Two small rivers (the Fredersdorfer Mühlenfließ and the Neuenhagener Mühlenfließ) form the boundary at the western and eastern limits of the model. Alternatively. Manual editing is often easier if being done in a 2D top view. The recommended tool for navigation in the FESlice view is the Pan tool in the View toolbar.1 m is used as the value for a 1st kind (Dirichlet) hydraulichead boundary condition. respectively. As they follow roughly the groundwater flow direction. two wells. The lake water level of 32. If you have accidentally closed it. a new view can be opened via Window > FE-Slice view. but entered manually. the type of boundary condition to be applied. The nodes of the northern border are highlighted as yellow points. Choose Border.to the 3D view. Click on OK. The selection is shown in the 3D view simultaneously. 33 Having this tool selected. Go to the Data panel and double-click on Boundary Conditions > Flow > Hydraulic-Head BC. Start the tool and select all slices in the upcoming dialog (manually or by hitting <Strg>-<A>). move the mouse cursor to the easternmost node and release the button. FEFLOW 6 II . A time-saving way to do this is the application of the Copy Selection to Layers/Slices tool. Bring up the 3D view and ensure that indeed all nodes at the northern boundary are selected. click on the westernmost node of the boundary and hold down the left mouse button. the selection is extended to the other three slices of the model. Select Nodes Along a Next. double-click on Hydraulic-Head BC in the Data panel to also show the boundary conditions in 3D. The values of all properties currently visible in the active view are shown in the Inspection panel. open the context menu by a right click on the symbol in the input box and choose Assign Values. rotate) in the View toolbar. The inspector tool can be closed by hitting <Esc> or by activating another tool (e. we store the current selection for later use: Open the context menu of the Spatial Units panel and choose Store Current Selection. Move the hair-cross on a node with a boundary condition. To give this selection a recognizable name.Demonstration Exercise To manually assign a hydraulic-head boundary condition make sure that the Assign Values method is active in the Editor toolbar (see figure). Click on Clear selection. 46 m in the text box of the and hit the Put Editor Value After defining the boundary condition at the northern boundary. Installation Guide & Demonstration Exercise 34 . which is activated by clicking ok Inspect nodal/elemental values in the Inspector toolbar. choose Rename from its context menu and change the name to “Northern Boundary”. II Blue circles appear around the selected nodes to indicate the Hydraulic-Head BC..g. If not. Enter toolbar button. While having the 3D view active. The values of the boundary condition can be checked using the inspector tool. top and bottom model boundaries. Copy the selection to all slices . 35 exercise_fri10. FEFLOW 6 II . They are assumed to be screened throughout the whole depth of the model. • Switch to the 3D view and check that the selection is set correctly. • Type 32.fem Southern Boundary The assignment of boundary conditions along the southern boundary is done in the same way: • In the FE-Slice view. • Store the selection and rename it to “Southern Boundary” for later use. • • Select nodes along a border. zoom/pan to the southern border. Pumping wells The wells are to be set in the southern part of the study area based on the map demo_wells. Remaining outer boundaries At nodes without an explicit boundary condition. which are assumed to be impervious except for groundwater recharge to be added later.• Clear selection afterwards. Therefore.fem exercise_fri11. • Make sure that Hydraulic-Head BC in the Data panel is still active. no further action is required for the western. eastern. FEFLOW automatically applies a no-flow condition.1 m in the input box of the Editor toolbar and click Put Value. make use of the corresponding map and select nodes close to the map points: • Double-click on demo_wells in Maps panel. Clear Selection. All boundary conditions are shown in the view. exercise_fri12. and four red symbols for each well. selected in the Spatial Units panel. Finally check all boundary conditions you have set. Go to the 3D view. Make sure that Domain is Installation Guide & Demonstration Exercise Blue circles are shown on the northern and southern border. So far.Demonstration Exercise Go to the FE-Slice view and browse to the slice 4 (<Pg Down>). where the well screen bottoms are located. Select the well locations again by clicking on Select by all map geometries and Copy selection to slices 1 and 2.fem 36 . the pumping wells are set on the bottom slice. This makes FEFLOW to connect these boundary conditions by a highconductive finite element. Enter 0 m³/d and click Put Value. • Double-click Boundary Conditions > Well BC in the Data panel. Double-click on Boundary Conditions > Flow in the Data panel. additional well boundary conditions are defined at the same location on the other slices. II • Click on Select by all map geometries in the Selection toolbar. To select the well nodes. pumping water from the second aquifer. Snap • Input 1 m in the input box of the Distance toolbar. Uncheck the checkbox of Geometry > Faces in the View Components panel to see into the domain. Clear Selection and browse to slice 3. To consider a well screen across all layers. In the Editor toolbar enter 1000 m³/d and click Put Value or hit <Enter>. The input procedures for material properties are completely analogous to the ones for process variables and boundary conditions. it is handled as a material property in FEFLOW.e. In a 3D model. the only exception is that material properties are assigned to elements instead of nodes: • Go to the 3D view.shp to the Maps Add maps(s)). isotropic materials are assumed.shp to the Maps panel. • Add the map year_rec.II. This shape file contains panel ( point-based conductivity values for the top aquifer in 10-4 m/s. i. This map is a polygon shape file containing the recharge data for different polygons in the study area. The unit of the values in the file is 10-4 m/d. conductivity does not depend on flow direction. the respective parameter to be set is In/Outflow on top/bottom. • Double click on … > year_rec > Linked Attributes > MEAN_YEAR -> In/Outflow on top/bottom • Click on Put Value in the Editor toolbar. • Activate In/Outflow on top/bottom in the Data panel with a double-click. • Close the dialog by clicking on OK..fem 37 Conductivity For this exercise. FEFLOW 6 II . exercise_fri13.3 Material properties Groundwater recharge Although groundwater recharge from the mathematical point of view is rather a boundary condition. • Choose the Select Complete Layer/Slice tool in the Selection toolbar and select the top layer by clicking on it.5. • Open the context menu of the map with a right-click and choose Link to Parameter… • Link the data field Mean_Year in the file to the FEFLOW parameter In/Outflow on top/bottom (in material properties). Add the map conduc2d. exercise_fri14. choose 3 and 0 % Over-/Under with Neighbors Shooting. • Activate (double-click) Drain-/fillable porosity in the Data panel. II Clear selection and select the third layer. Linear. • Clear selection. clicking 1e-6 m/s to the second layer. Press <Enter>. Editor toolbar to Switch the input tool in the Maps input (with a right-click on the icon in the input box). Double-click on Conductivity [Kxx]. the drain-/fillable porosity is set (also often referred to as specific yield). For Akima. then press <Ctrl> and double click on Conductivity [Kyy] Data panel. Kyy and Kzz by defining three links. Switch to the Assign values method by clicking on the icon in the input box of the Editor toolbar and assign a value of Installation Guide & Demonstration Exercise 0.fem Drain-/fillable porosity As the next material property. each single link. We set a constant value for each layer. choose the Select Complete Layer/Slice tool in the Selection toolbar and select it. Assign a value of 1e-4 m/s to the third layer and hit <Enter>.Demonstration Exercise Link to Parameter…) the attribute Associate ( column CONDUCT to the FEFLOW parameters Kxx. Make sure that conduc2d is set as the map in the input box and assign the data by Put Value.1 and hit <Enter>. and Conductivity [Kzz] in the If the top layer is no longer selected. both value and unit as the unit m/s does not correspond to the default unit in FEFLOW. click on it. • Input a value of Select com- Clear selection and select the elements in the second layer applying Select Complete Layer/Slice again. To select one of the links for editing its properties. 38 . Clear selection. Make sure to input. • Select the first layer by using the plete layer/slice tool. this model cannot be saved as the number of nodes per slice exceeds the allowed maximum of 500. The Error Norm History diagram provides information about the remaining error in each simulation iteration. • Assign 0. the system is solved iteratively.01 to the selection. Please use the prepared file in this case.fem 39 II. Start in the All other material properties are used with their respective default values in this exercise. the error reaching values below the defined error criterion. Select exercise_fri15. • Assign 0. The simulation stops after eight iterations. Select com- The flow part of the flow and transport model is complete. taking into account that the saturated thickness of unconfined layers depends on the actual solution for hydraulic head. Starting the simulator To run the simulation.fem • Select the third layer by using the plete layer/slice tool. FEFLOW 6 II . The result with the element faces turned on again in the View Components panel is shown in the figure. As the model is unconfined. the process variables will change and you would lose the initial conditions of the model. During the simulation.2 to the selection. exercise_fri15.6 Simulation • Clear selection. The simulation is run in steady-state mode. • Select the second layer by using the complete layer/slice tool. save the model to be able to return to the initial properties later! If running FEFLOW in demo mode. It is worth the time doing a test run now to ensure that the flow model is set up correctly. In case that FEFLOW is run in licensed mode. • Clear selection.It is recommended to save the file before starting the simulation (if working with a license). click Simulator toolbar. II Budget To check whether the model indeed has reached an equilibrium state.even with identical input parameters. During and after simulation the run.Demonstration Exercise On computers with multi-core CPUs or multiple CPUs the simulation result and budget result may be slightly different in each run . all visualization tools in FEFLOW can be used to monitor the simulation results. Installation Guide & Demonstration Exercise 40 . especially when being done at each time step during a simulation run. When visualizing results in the 3D view. The budget shows inflows in red. the overall water balance can be calculated. outflows in blue for the different boundary condition types and the areal sources and sinks (groundwater recharge). Check the Active checkbox to activate the budget calculation. For example. go to the Data panel and double-click on Process Variables > Flow > Hydraulic head for visualization of the resulting hydraulic head distribution. The budgeting is turned off by default as it can cause significant computational effort. If it has been closed accidentally. open the Budget panel via View > Panels > Budget Panel. The Budget panel provides the means for this. The top of the model always exactly matches the water table elevation. This is due to possibly different summation order when using parallelization. especially at the beginning of the simulation vertical mesh movement caused by the free & movable mode can be observed. The Balance value as the sum of all water flows is sufficiently small to accept the solution as steady state. 41 Activate (double-click) the map waste_disposal in the Maps panel. In the Spatial Units panel. multiple pathlines are released from all the nodes in the areas of the contamination sources. With a click into the wastedisposal area the nodes of the contamination source are added to the selection. In our case. Snap Distance toolGo to the 3D view and uncheck Geometry > Faces in the View Components panel. click on Current Selection > Node selection. First. a selection is created containing all the nodes on the model top within the contamination source areas. In the Data panel double-click on Process Variables > Flow > Pathlines > Forward. Repeat the steps for the sewage_fields map. After a short time for computation. Pathlines are calculated by tracking the path of virtual particles that are released at certain starting points (called seeds). Set the Snap distance in the bar to 1 m. Without this step the opaque element faces around the outer model domain would conceal the pathlines located inside the model.Pathlines One way to visualize the flow field is the plotting of pathlines. Choose the tool Select by Map Polygon from the dropdown menu in the Selections toolbar. In the Data panel make sure that Hydraulic head or any other nodal property is active to ensure the nodal selection mode rather than the elemental one. The result looks like this: FEFLOW 6 II . Go to the FE-Slice view and browse to slice 1. the pathlines are shown in the 3D view. Confirm with Apply.Demonstration Exercise II.7. go to Edit > Problem Settings and open the Problem Settings dialog. To be able to provide quantitative estimations. exercise_fri15. the streamline-based evaluation does take into account any mixing processes due to dispersion. For this purpose. select Flow and Mass Transport and Steady flow/transient transport.fem II. Therefore before starting to add the mass transport properties. the previously saved model has to be loaded again to return to the original model. After the run.7 Flow and Transport Model II When the flow model has been run. it does not contain the initial conditions any more. The eastern well seems not to be influenced by either contamination source. the process variable Hydraulic head has changed. In addition. Installation Guide & Demonstration Exercise 42 . However. the model is extended to a flow and mass transport model. a transport model is needed. In Problem Class. From the result it can be seen that the western well is certainly influenced by the sewage treatment plant. but the final results. the moving mesh technique has changed the elevation of the slices. To change the problem class.1 Problem settings Problem class From the preliminary pathline analysis based on the results of the flow model it is obvious that the contamination sources are located within the catchment zone of the production wells. Hereby. and confirm by clicking on Yes. exercise_fri16. turn on the Upwinding option Shock capturing. Enter a value of input box. Switch to the Forward Euler / Backward Euler (FE/BE) time-integration scheme for improving model stability. OK to apply the changes and to close Click on the Problem Settings dialog. FEFLOW uses an automatic time-step control scheme.fem FEFLOW 6 II . Click on Apply. By default.43 Time Stepping In a transient model temporal discretization has to be defined. 7300 days in the Final Time Numerical Parameters On the Numerical Parameters page. The corresponding settings can be found on the Temporal Properties page. an appropriate time-step length is determined internally by monitoring the changes in the primary variables (hydraulic head in a flow simulation). This dampening technique helps to suppress numerical oscillations at steep concentration gradients with only a minimum of additional dispersion. Choose Inverse Distance as the Data Regionalization Method and use 4 Neighbors and Exponent of 2. The 3D view shows the default initial concentration of 0 mg/l. The contamination in both areas is found to reach down to the top of the aquitard. No changes are necessary for the background concentration. Go to the Maps panel and add the map file conc_init. Click on OK. Use Copy Installation Guide & Demonstration Exercise Double-click on CONC -> Mass concentration in the Maps panel and assign the values by clicking on Put Value.7. Double-click on Process Variables > Mass transport > Mass Concentration in the Data panel.fem Do not forget to select the Domain entry again in the Spatial Units panel before continuing (otherwise no model properties can be plotted in the active view)! 44 . Clear selection. II Contamination sources The contamination sources are represented by a higher initial concentration in the areas of the wastewater treatment plant and the landfill within the first aquifer. First. Make sure the Snap distance is set to 1 m in the Snap Distance toolbar. Repeat the same steps with the sewage_fields map to add also these nodes to the selection. a selection of the nodes belonging to the contamination source is needed.shp. representing fresh water. Selection to Slices/Layers to copy the selection to slice 2. activate (double-click) the map waste_disposal. The initial concentrations in these areas are to be interpolated from observation data. exercise_fri17. Associate ( Link to Parameter…) the attribute column CONC to the FEFLOW parameter Process Variables > Mass transport > Mass concentration by defining the link. In the Maps panel. Double-click on Process Variables > Mass transport > Mass Concentration in the Data panel.2 Initial conditions Switch to the 3D view.Demonstration Exercise II. Go to the FE-Slice view and browse to slice 1. Click Select by All Map Geometries in the Selections toolbar. In the 3D view all nodes along both borders are shown as selected. the constraint is set to limit the mass flux to a minimum value of 0 g/d. Double-click on Boundary Conditions > Mass Transport > Mass-Concentration BC in the Data panel. applying the concentration boundary condition only for inflowing water. at these boundaries also outflow is possible. This requires a dynamic change of the mass transport boundary condition depending on the flow direction. Repeat these steps with the node selection Southern Boundary. input a value of 0 mg/l and click Put Value. for the sake of clarity. the constraint conditions are not shown by default as properties in the data panel and have to be added first: In the Data panel. Blue circles indicate that fist kind boundary conditions are set. Therefore a fixed concentration of 0 mg/l is assigned as a boundary condition at these locations. open the context menu of Boundary Conditions > Mass transport > MassConcentration BC and choose Add Constraint > Min. A constraint in our case is used to limit the flux at a 1st kind boundary condition (fixed head/concentration/temperature) to a minimum or maximum value. a free outflow of contaminated water is to be preferred over a fixed concentration. Go to the Spatial Units panel and open the context menu of the previously stored node selection Northern Boundary. similar to the flow boundary conditions. which can be implemented by introducing a boundary constraint condition. ensure that the Assign Values mode is active. mass-flow constraint. The constraints are technically applied in the same way as boundary conditions. However. Choose Add to current selection. water entering the model at the northern or southern border is fresh water. In this case. Depending on the actual flow direction. Boundary constraint conditions As stated before.7. In the Editor toolbar. For this exercise. however. 45 FEFLOW 6 II .3 Boundary Conditions Northern and southern boundary Any water entering the domain through the northern or southern boundary is fresh water with a concentration of 0 mg/l.II. Click on Domain in the Spatial Units panel. A good choice to minimize errors due to the nodal nature of the calculated velocity field is to apply thin layers on top and bottom of the aquitard. this model layer has to be further subdivided. Select all elements of the model. the porosity effective for mass transport processes is assumed to be 20 % throughout the model. exercise_fri19. For Boundary Conditions Inflows are negative (-). outflows are negative (-). The minimum constraint is indicated by a bar below the associated boundary condition symbol.fem II. exercise_fri18. Input a value of and hit <Enter>. 7 m) for all elements of the model.4 Material properties To simplify the data input.Demonstration Exercise Algebraic signs are handled differently for Constraint and Boundary Conditions: For Constraint Conditions inflows are positive (+). 0. Expand the tree view and activate (double-click) Min. mass-flow constraint and assign 0 g/d to all the selected nodes with <Enter>. outflows are positive (+).7. 70 m) and for the transverse dispersivity (Material Properties > Mass transport > Transverse dispersivity.5 Vertical resolution To ensure a correct representation of low flow velocities in the aquitard as a basis for transport simulation. Go to the 3D view and activate (double click) Material Properties > Mass transport > Porosity in the Data panel. Installation Guide & Demonstration Exercise 46 .fem II. The easiest way to do this is to click Select All in the Selection toolbar. Clear selection.2 in the Editor toolbar II Repeat these steps for the longitudinal dispersivity (Material Properties > Mass transport > Longitudinal dispersivity.7. Clear selection. Go to Edit > 3D Layer Configuration. The new slice is inserted into the model with the slice number 3. The two additional slices are placed within the aquitard with a distance of 10 cm to the aquitard top and bottom. The nodal parameters of the old slice 2 are inherited to the new slices 2 and 3.choose the option lower slice. 5 and hit 47 In the upcoming Slice Partitioner dialog. The Slice placement dialog is opened. while the information from the old slice 3 is to be inherited by slices 4 and 5. In this list. Increase the Number of layers to <Enter>. The aquitard has been divided into three layers. Change the option to upper slice. Data flow for layers describes the data flow for all material data and for elemental selections.1 m in the Distance input box and . The upper control called Data flow for slices describes the data flow of the process variables. The lower list. To ensure that the data is transferred correctly from the old to the new slices and layers. the Data Flow lists on the right of the 3D Layer Configurator are used. choose where the first new slice is being inserted. checking the checkbox. Select New slice 3 and click on OK. Increase the Number of layers in the input box in the upper left corner of the dialog by one (to 4). The data flow is symbolized by lines connecting the old with the new slices.for inserting the first additional slice . and nodal selections from the old slices to the new ones.The next slice is to be inserted 0. The old slices are shown as number buttons in the left column. the new ones in the right column. FEFLOW 6 II . The slice numbers refer to the NEW slice configuration.1 m below the second slice. Set its status to Fixed. There are two lists that provide control over the data flow between the previous and the new slices and layers. Press <Enter>. boundary conditions. select New slice 3 again and click on OK. Type a value of 0. 7. the attribute columns of the map are associated to the properties of the observation points.. II.Demonstration Exercise FEFLOW suggests to transfer the properties from old slice 2 to slices 2 – 4. the link from old slice 2 points to new slices 2-3 and from old slice 3 to new slices 4-5. double click on the button 5 in the new column. No changes are necessary. II exercise_fri20.shp. Add this map to the Maps Add map.6 Reference data Observation points A network of observation wells exists in the study area. The X-Y locations of the observation wells as well as their respective relation to a certain depth (slice number) are contained in the shape file obs_points. In the following dialog. Click on OK to exit the 3D Layer Configurator and to apply the changes to the model. Change this entry to 4 – 5. the concentration development over time at these monitoring points is shown and logged during the simulation. Click on OK to create the set of observation points. 3 and 4. In order to change this. The data flow in the lower list for the material properties describes the same data characteristics from the old bottom layer (lower aquifer) to the new layers 2.fem Installation Guide & Demonstration Exercise 48 . Open the context menu of the map obs_points and choose Convert to > Observation Points. Choose the field SLICE for the Slice Number and TITLE for the Label. Click on Set/Clear Observation Points in the Observation Point toolbar to show the imported observation points in the view. from the context menu).. As a result. For a later comparison between measured and calculated data. For Node Number choose <no node>. panel ( Go to the FE-Slice view. it is not possible to save the results file. Confirm by clicking OK. The current simulation time is displayed in the dropdown box of the Simulator toolbar. the results file (*.49 exercise_fri21. click Start in the Simulator toolbar.fem II. The simulation takes approximately 15 minutes on a system with 2GB RAM and an Intel Core Duo processor.7. the results can be saved to a file during the simulation run. Click on Record in the Simulator toolbar. Activate Save complete results (DAC file). If running FEFLOW in demo mode. exercise_fri21.dac) is saved with the same name as the current model in a subdirectory results. By default. FEFLOW 6 II . and only the prepared file can be run.7 Simulation Run If working with a licensed version of FEFLOW.fem To run the model. Click on the waste-water treatment plant (the contamination source in the north-west) to define the starting point of the line here.7. The mostly steady conditions lead to a steadily increasing time step length. we are interested in the vertical distribution of the contamination along the contamination plumes. Follow the flow path to the western well and further to the lake Müggelsee.Demonstration Exercise In the Time Steps diagram (which can be opened via View > Diagrams if not already shown) the actual time step length versus total simulation time is plotted. The cross section is based on a 2D Surface Line. Finish the line with a double click. Choose Tool > Draw a Surface (2D) Line. Click Stop to leave the simulator. Switch to the FE-Slice view and open its context menu. II. The simulation stops after 7.8 Postprocessing Load the recorded results file. exercise_fri21.300 days (the final time that has been set in the Problem Settings dialog before). The line is extended by adding points with a mouse click. The final result should look like this: Installation Guide & Demonstration Exercise 50 . Repeat these steps for the waste dump (the eastern contamination source).dac II Cross-sections Process variables and material properties can be visualized in cross-section views. In our case. In the Spatial Units panel. go to the Projection tab and push up the lever to exaggerate the z-axis. In the Navigation panel. FEFLOW 6 II . two new entries Surface Locations > 2D Polyline #1 / #2 have been added.51 A cross-section view along the line is opened. Open the context menu of 2D Polyline #1 and choose Cross-Section View. In the View Components panel.Demonstration Exercise Isosurfaces Go to the 3D view. Properties double-click on Isosurfaces. To edit the isosurface visualization properties. Switch to the Custom mode and click on Edit. In the selected in the Data panel. The panel comes to front. II Installation Guide & Demonstration Exercise 52 . and click Apply in the by clicking Properties panel. Close the dialog OK. 10 mg/l and 20 mg/l. This completes the demonstration exercise. double-click on Mass concentration to show this parameter in the view. Check and Mass concentration > Mass concentration > Isosurfaces > Domain. Make sure that Domain is Spatial Units panel. One isosurface for an average concentration is shown. uncheck Faces Continuous. The isosurface visualization is changed to reflect the newly set concentrations. Additional tutorials are available in the User Manual. Specify two values.