1. Free vs. Forced ConvectionFEFLOW ® Exercise Salt intrusion from top Vertical cross section

2. Free vs. Forced ConvectionFEFLOW ® Exercise Spatial Discretization Automatic mesh generation (~3000 triangular elements) Mesh refinement (via Rubberbox and Border Options) FEFLOW Mesh Generation Height approx. 100 m

3. Free vs. Forced ConvectionFEFLOW ® Exercise Model Set-up FEFLOW Basic Settings 2D (default) Problem Class: Flow and Mass (steady flow, transient transport) Vertical problem projection Temporal and control data: Automatic time stepping, FE/BE time integration Final time: 36500 days (100 years)

4. Free vs. Forced ConvectionFEFLOW ® Exercise Flow Problem - Material parameters Global: Density ratio  = 10 -3  Input 10 [10 -4 ] Model Set-up

5. Free vs. Forced ConvectionFEFLOW ® Exercise Flow Problem - Boundary Conditions Impermeable border (default) 1 st -kind boundary condition at an arbitrary node, e.g., upper left: h = 0 m Model Set-up

6. Free vs. Forced ConvectionFEFLOW ® Exercise Mass-Transport Problem - Boundary Conditions Implemented as 1 st -kind boundary condition in the center section of the upper border (via Border- Option) Concentration at the spill site: 100 mg/l C = 100 mg/l Model Set-up

7. Free vs. Forced ConvectionFEFLOW ® Exercise Numerical Solution FEFLOW Options Direct equation solver

8. Free vs. Forced ConvectionFEFLOW ® Exercise FEFLOW Ergebnis Free convection Numerical Solution

9. Free vs. Forced ConvectionFEFLOW ® Exercise Base model – Save…

10. Free vs. Forced ConvectionFEFLOW ® Exercise Model Extension Flow Problem - Boundary Conditions Horizontal hydraulic gradient (‘strong’) Implemented as 1 st -kind boundary condition along the left and right vertical borders (via Border-Option): left side:h = 0 m right side:h = 0.1 m

11. Free vs. Forced ConvectionFEFLOW ® Exercise FEFLOW Result Flow is dominated by forced horizontal convection Numerical Solution

12. Free vs. Forced ConvectionFEFLOW ® Exercise Reducing the boundary-condition value on the right vertical border (via Debug option): right side:h = 0.01 m Model Modification Flow Problem - Boundary Conditions Horizontal hydraulic gradient (‘weak’)

13. Free vs. Forced ConvectionFEFLOW ® Exercise Combined effects of free and forced convection FEFLOW Result Numerical Solution