Point Probe

As an alternative to “Observation Nodes,” which need to be defined on FE nodes and before calculations are carried out, Hydrus also provides an option to specify “Point Probes,” which can be defined anywhere in the transport domain (independent of FE nodes) and after calculations are done.

When presenting simulation results, HYDRUS displays these “Point Probes” and values of a particular displayed quantity (e.g., water contents or concentrations). Since “Point Probes” are specified after the simulation is finished, HYDRUS cannot display continuous time series as for Observation Nodes, but only values at pre-specified Print Times. When the Point Probe is not located directly on a FE node, the quantity value is linearly interpolated from the corner values of a particular finite element.

Edit commands for Point Probes:

A Point Probe can be inserted using the Point Probe command, available on the Insert Menu. One can create a set of Point Probes either a) numerically using a table in the New Point Probe dialog window or b) graphically after clicking on the button “Set Graphically.” When defining Point Probes numerically, one must predefine their number (Number of Points) and click on the Update button to update the table before entering Point Probe coordinates.

When defining Point Probes graphically (after clicking the button Set graphically), one defines Points in the View window directly on the Transport Domain using the mouse (clicking the left mouse bottom at selected locations):

Point Probes (and associated quantity values) can be displayed or hidden using the Show Point Probes check box on the “Edit bar – Results” tab (in the section “Tools and Options”).

The Point Probes can be Deleted, Inserted, Saved, and Edited using the command in the “Current Point Probe” section of the “Edit bar – Results” tab (see the figure below).

The Point Probes can be grouped into multiple named groups. The initial set of Point Probes is denominated 0 - Temporary. To save it permanently, use the Save Probe Copy button on the Edit Bar below the list of point probes. A new dialog box is opened where you can define the Name of the Group of Probe Points and check the coordinates of each point.

There are several Snap modes (Points Probes can be defined on different geometrical objects) in the dialog Insert Probe Points:

All saved Point Probes are shown on the Navigator Bar under the Auxiliary Objects, where one can select various Edit Commands using the right mouse button click, for example, Edit and Delete.