Properties and Conditions on FE-Mesh

Various spatially variable properties (e.g., material distribution, initial conditions, etc) can be specified in Version 3.0 of HYDRUS either:

a) directly on the Finite Element Mesh (as done in Versions 1.0 and 2.0), or

b) on Geometric Objects (e.g., boundary curves, rectangles, circles, surfaces, volumes) (in Version 2.0).

To be able to define properties on Geometric Objects, one needs to first enable this option (Edit domain properties, initial and boundary conditions on geometric objects) in the Domain Type and Units dialog window.

The main advantage of the latter case is that when the FEM is changed, these properties are not automatically lost, but can be recalculated to the new FEM from their definition on Geometric Objects. Which option is used depends on the menu command Edit->Properties and Conditions on FE-Mesh. A similar button switch is also available at the end of the tool bar, next to the Results button.

All properties can be transferred from Geometric Objects to FE-Mesh using the menu command Edit->Transfer all Properties to FE-mesh.

More details about How to Define Properties on Geometric Objects.

Notes on Properties at Geometrical Objects:

1. When the same pressure head initial condition involving either "equilibrium from the lowest located point" or "a linear distribution" is chosen for multiple surfaces, then this condition is applied globally to all selected surfaces (e.g., a single point with the lowest z-coordinate is found for all selected surfaces).
2. Nodes that are at the boundary line shared by two surfaces (or at the surface shared by two volumes) are assigned values calculated using the condition with a higher number.
3. This option is not available for the Lite Version of HYDRUS.