GMS:SEEP2D: Difference between revisions
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#*''Units'' - The '''Units''' button brings up the [[GMS:Units|''Units'']] dialog. This dialog is used to enter the units for length, time, concentration, etc. for the simulation. GMS uses the selected unit options to display the appropriate units next to each input edit field in the other SEEP2D dialogs. | #*''Units'' - The '''Units''' button brings up the [[GMS:Units|''Units'']] dialog. This dialog is used to enter the units for length, time, concentration, etc. for the simulation. GMS uses the selected unit options to display the appropriate units next to each input edit field in the other SEEP2D dialogs. | ||
#*''Problem Type'' - The problem type must be specified either as plane flow or axisymmetric flow. The axisymmetric option should be selected for models corresponding to flow to a single well as described in the SEEP2D Primer. All other models should use the plane flow option. | #*''Problem Type'' - The problem type must be specified either as plane flow or axisymmetric flow. The axisymmetric option should be selected for models corresponding to flow to a single well as described in the SEEP2D Primer. All other models should use the plane flow option. | ||
#*''Flow Lines'' - If the Compute flow lines option is turned on, once the head solution is computed, SEEP2D will reverse the boundary conditions and compute flow potential values at the nodes. These values can be contoured by GMS using the Flow lines option is the SEEP2D Display Options dialog. | #*''Flow Lines'' - If the Compute flow lines option is turned on, once the head solution is computed, SEEP2D will reverse the boundary conditions and compute flow potential values at the nodes. These values can be contoured by GMS using the Flow lines option is the ''SEEP2D Display Options'' dialog. | ||
#*''Model Type'' - The model type should be selected as either Confined or Unconfined. For confined models, the entire model domain is assumed to be saturated. No exit face boundary conditions should be applied and the unsaturated zone material properties are not required. For unconfined models, two options are available for dealing with the unsaturated zone: (1) deforming mesh and (2) saturated/unsaturated flow modeling. For both types of problems, exit face boundary conditions should be applied along the boundary of the mesh where the free surface is expected to exit. With the deforming mesh option, SEEP2D iterates to find the location of the phreatic surface and the mesh is deformed or truncated so that the upper boundary of the mesh matches the phreatic surface. The solution files from this type of simulation include a geometry file containing the deformed mesh. With the saturated/unsaturated option, the mesh is not modified and the flow in both the saturated and unsaturated zone is modeled. The hydraulic conductivity in the unsaturated zone is modified (reduced) using either the linear frontal method or the Van Genuchten method. The equations used by both methods are described in more detail in the SEEP2D Primer. | #*''Model Type'' - The model type should be selected as either Confined or Unconfined. For confined models, the entire model domain is assumed to be saturated. No exit face boundary conditions should be applied and the unsaturated zone material properties are not required. For unconfined models, two options are available for dealing with the unsaturated zone: (1) deforming mesh and (2) saturated/unsaturated flow modeling. For both types of problems, exit face boundary conditions should be applied along the boundary of the mesh where the free surface is expected to exit. With the deforming mesh option, SEEP2D iterates to find the location of the phreatic surface and the mesh is deformed or truncated so that the upper boundary of the mesh matches the phreatic surface. The solution files from this type of simulation include a geometry file containing the deformed mesh. With the saturated/unsaturated option, the mesh is not modified and the flow in both the saturated and unsaturated zone is modeled. The hydraulic conductivity in the unsaturated zone is modified (reduced) using either the linear frontal method or the Van Genuchten method. The equations used by both methods are described in more detail in the SEEP2D Primer. | ||
#'''Assign the material properties''' - Each element in the 2D mesh is assigned a material ID. The material properties are assigned to each element using these IDs and a list of material properties. The material properties specific to SEEP2D are entered using the '''''Material Properties''''' command in the SEEP2D menu. This command brings up the | #'''Assign the material properties''' - Each element in the 2D mesh is assigned a material ID. The material properties are assigned to each element using these IDs and a list of material properties. The material properties specific to SEEP2D are entered using the '''''Material Properties''''' command in the ''SEEP2D'' menu. This command brings up the ''SEEP2D Material Properties'' dialog. The items in the dialog are as follows: | ||
#*''List of Materials'' - The currently defined materials are listed at the top of the dialog. The values for a material are entered by selecting the material and editing the values in the lower part of the dialog. | #*''List of Materials'' - The currently defined materials are listed at the top of the dialog. The values for a material are entered by selecting the material and editing the values in the lower part of the dialog. | ||
#*''Soil Coefficients'' - The hydraulic conductivity in the two major principal directions and the angle from the x-axis to the major principal axis are entered in the Soil Coefficients section. These hydraulic conductivity values represent the hydraulic conductivity for saturated conditions. | #*''Soil Coefficients'' - The hydraulic conductivity in the two major principal directions and the angle from the x-axis to the major principal axis are entered in the Soil Coefficients section. These hydraulic conductivity values represent the hydraulic conductivity for saturated conditions. | ||
#*''Van Genuchten Parameters'' - If the Van Genuchten Saturated/Unsaturated option has been selected in the | #*''Van Genuchten Parameters'' - If the Van Genuchten Saturated/Unsaturated option has been selected in the ''SEEP2D Analysis Options'' dialog, the Van Genuchten alpha and n-value numbers must be defined. | ||
#*''Linear Front Parameters'' - If the Saturated/Unsaturated with Linear Front option has been selected in the | #*''Linear Front Parameters'' - If the Saturated/Unsaturated with Linear Front option has been selected in the ''SEEP2D Analysis Options'' dialog, the minimum pressure head (ho) and minimum relative conductivity (kro) values must be defined. | ||
#'''Assign the boundary conditions''' (either with a conceptual model or with the 2D mesh tools) - Two general types of boundary conditions can be defined for SEEP2D simulations: nodal boundary conditions and flux boundary conditions. (See [[GMS:SEEP2D#SEEP2D Boundary Conditions|SEEP2D Boundary Conditions]]) | #'''Assign the boundary conditions''' (either with a conceptual model or with the 2D mesh tools) - Two general types of boundary conditions can be defined for SEEP2D simulations: nodal boundary conditions and flux boundary conditions. (See [[GMS:SEEP2D#SEEP2D Boundary Conditions|SEEP2D Boundary Conditions]]) | ||
#'''Run the [[GMS:Model Checker|Model Checker]].''' | #'''Run the [[GMS:Model Checker|Model Checker]].''' | ||
#'''Save the simulation''' | #'''Save the simulation''' | ||
#'''Run the simulation''' | #'''Run the simulation''' | ||
#'''Display the results''' - Before reading in the solution file for post-processing in GMS, it is often useful to examine the text output listing file. The output file can also be viewed by simply double-clicking on the *.out file found in the [[GMS:SEEP2D Solution|SEEP2D solution]] folder in the [[GMS:The GMS Screen|Project Explorer]]. Also, any text file can be viewed by selecting the '''Edit File''' command in the | #'''Display the results''' - Before reading in the solution file for post-processing in GMS, it is often useful to examine the text output listing file. The output file can also be viewed by simply double-clicking on the *.out file found in the [[GMS:SEEP2D Solution|SEEP2D solution]] folder in the [[GMS:The GMS Screen|Project Explorer]]. Also, any text file can be viewed by selecting the '''''Edit File''''' command in the ''File'' menu. The File Browser appears and the selected file is opened in a text editor. Once the solution is imported to GMS, a variety of options are available for displaying the solution. The total head and pressure head data sets can be contoured. Velocity vectors corresponding to Darcy velocity can be plotted. If the Compute flow lines option was selected, a complete flow net may be plotted by displaying contours of total head (equipotential lines) and turning on the Flow lines option in the ''SEEP2D Display Options'' dialog. | ||
==SEEP2D Boundary Conditions== | ==SEEP2D Boundary Conditions== | ||
Two general types of boundary conditions can be defined for SEEP2D simulations: nodal boundary conditions and flux boundary conditions. The type or value assigned to a previously defined boundary condition can be edited by selecting the node or node string and selecting either the '''''Node BC''''' or '''''Flux BC''''' commands. A boundary condition can be deleted by selecting the boundary condition using either the Select Node or Select Node String tools and selecting the '''''Delete BC''''' command in the | Two general types of boundary conditions can be defined for SEEP2D simulations: nodal boundary conditions and flux boundary conditions. The type or value assigned to a previously defined boundary condition can be edited by selecting the node or node string and selecting either the '''''Node BC''''' or '''''Flux BC''''' commands. A boundary condition can be deleted by selecting the boundary condition using either the Select Node or Select Node String tools and selecting the '''''Delete BC''''' command in the ''SEEP2D'' menu. | ||
===Nodal Boundary Conditions=== | ===Nodal Boundary Conditions=== | ||
The most common type of SEEP2D boundary conditions is nodal boundary conditions. Nodal boundary conditions are assigned by selecting the nodes and selecting the '''''Node BC''''' command in the | The most common type of SEEP2D boundary conditions is nodal boundary conditions. Nodal boundary conditions are assigned by selecting the nodes and selecting the '''''Node BC''''' command in the ''SEEP2D'' menu. When selecting the nodes, either the [[GMS:2D Mesh Tool Palette|Select Node]] tool or the [[GMS:2D Mesh Tool Palette|Select Node String]] tool may be used. The '''''Node BC''''' command brings up the ''Node BC'' dialog. Three types of nodal boundary conditions can be assigned: head, exit face, and flow rate. | ||
[[Image:SEEP2D_CM.gif|right|frame|Sample SEEP2D Problem Showing Boundary Conditions|300px]] | [[Image:SEEP2D_CM.gif|right|frame|Sample SEEP2D Problem Showing Boundary Conditions|300px]] | ||
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Flux boundary conditions are used to specify a known flux rate [L/T] along a sequence of element edges on the perimeter of the mesh. They are often used to simulate infiltration. Flux into the system is positive and flux out of the system is negative. | Flux boundary conditions are used to specify a known flux rate [L/T] along a sequence of element edges on the perimeter of the mesh. They are often used to simulate infiltration. Flux into the system is positive and flux out of the system is negative. | ||
Flux BC are assigned by selecting a sequence of nodes along the mesh boundary using the Select Node String tool and selecting the '''''Flux BC''''' command in the | Flux BC are assigned by selecting a sequence of nodes along the mesh boundary using the Select Node String tool and selecting the '''''Flux BC''''' command in the '''SEEP2D'' menu. This command brings up a simple prompt for the flow rate. | ||
==Reading the [[GMS:SEEP2D Solution|SEEP2D Solution]]== | ==Reading the [[GMS:SEEP2D Solution|SEEP2D Solution]]== | ||
Once the simulation is completed, the solution is automatically imported to GMS for post-processing. The solution files are organized in a SEEP2D solution folder in the [[GMS:The GMS Screen|Project Explorer]]. If the unconfined/deforming mesh option is selected, the solution will consist of two files: a geometry file that contains the deformed mesh and a solution file that contains the head, velocity, and flow potential data sets. If any of the other analysis options is selected, only the solution file is saved. Regardless of which option is used, the solution can be quickly imported to GMS using the '''''Read Solution''''' command in the | Once the simulation is completed, the solution is automatically imported to GMS for post-processing. The solution files are organized in a SEEP2D solution folder in the [[GMS:The GMS Screen|Project Explorer]]. If the unconfined/deforming mesh option is selected, the solution will consist of two files: a geometry file that contains the deformed mesh and a solution file that contains the head, velocity, and flow potential data sets. If any of the other analysis options is selected, only the solution file is saved. Regardless of which option is used, the solution can be quickly imported to GMS using the '''''Read Solution''''' command in the ''SEEP2D'' menu. The solution data sets are organized into a SEEP2D solution folder in the Data Tree. | ||
==SEEP2D Files== | ==SEEP2D Files== | ||
