HydroGeoSphere/Properties Guidelines

Types of media

Currently, the following basic types of media can be defined in HydroGeoSphere:

1. porous
2. dual continuua
3. discretely-fractured
4. surface runoff
5. channel flow
6. et

Porous media and dual continuua are defined by three-dimensional 8-node (brick) or 6-node (prism) elements, discretely-fractured, surface flow and ET media are defined by two-dimensional 4-node (rectangle) or 3-node (triangle) elements and channel flow media are defined by 1-node (line) elements. By default, every 3-D element in the problem domain is a porous media element. Elements of the other four types of media may or may not be defined for a specific problem.

Elements

Each porous media element is assigned a zone (i.e. material) number during grid generation. In simple cases, all elements will be assigned a zone number of 1, while in more complex cases, elements may have been assigned different zone numbers. For example, if a multilayered grid was generated using the instruction Generate layers from slice then the elements would have been assigned zone numbers based on the layer number (i.e. elements in the lowest layer number 1 would be assigned a material number of 1).

By default, all zones, and therefore all elements in the domain, are assigned the same default porous media properties, which are listed in Table 5.5. These values are set in software and cannot be modified by the user unless the code is changed and recompiled. However, there are other ways of changing the porous media zone properties as we will discuss below.

The first step in modifying zoned properties for a given problem is to indicate which type of medium is to be manipulated. The following instruction does this:

Use domain type

1. zone_type Can be one of the strings: porous media, dual, fracture, surface, channel or et.

Causes grok to read a string defining the type of domain to which additional instructions should be applied.

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