MODELING TASK DESCRIPTION
In many groundwater applications, the impact or drawdown of a well extraction/injection is of interest. In such cases, the difference of the hydraulic head distribution compared to an initial state is typically calculated. With FEFLOW, simulation results can be displayed without post-processing in third-party software. Follow the workflow below to learn the necessary steps:
SOLUTION
FEFLOW can calculate the drawdown by time, for example, the Hydraulic head at time step 0 minus the Hydraulic head at the current time-step in the following way:
Step #01 - Create a Nodal Expression in the Data Panel under /User Data- see Fig. 1
Fig. 1 - How to add Nodal Expressions
Step #02 - Rename the user distribution, then open the Expression Editor by right-clicking and selecting Edit Parameter Expression... - see Fig. 2
Fig. 2 - Open the Expression Editor
Step #03 - Define the expression corresponding to the formula Head @(0)-Head - see Fig. 3
Fig. 3 - Edit the expression
Step #04 - Run the .fem file after you specified the result file name (.dac) and folder location. Open the .dac file and you will be able to plot the results of the drawdown by double-clicking on the Nodal Expression created in step #01 in the Data panel - see Fig. 4. The head differences can be displayed for any recorded time-step during the simulation including the final one.
Fig. 4 - The results of the Drawdown calculation
FURTHER INFORMATION & USEFUL LINKS
Manuals and Guidelines
FEFLOW 11 Documentation - User Data
FEFLOW 11 Documentation - Expression Editor
FEFLOW 11 Documentation - Expression-Based Parameter Assignment