The following dialogue appears:

A path line is the line that describes the path/trajectory of a water particle over a flow time t. Trajectories are calculated by tracing the path of an imaginary water particle through the flow field. The calculation of transient trajectories differs in that the velocity field changes at each time step. In addition to the trajectory sections s, it is therefore checked that the flow time t is not greater than the time step length T.

The path line export can be stored in any folder.

Various output formats are offered:

• SPRING results data

• STR: in structure data format

• CSV: in csv format with x, y, z, vx, vy, vz for each path line segment

• VTU: as VTK data set for visualisation programs

• An error indicator can be calculated

The path lines can be exported over the entire calculation period as well as for defined time step intervals. A restriction via the minimum speed and the maximum distance or flow time is also possible

The starting points for path lines can be located around nodes, in element centres or at any coordinates x, y, (z).

The direction of the path line tracking can be selected in the direction of flow or in the opposite direction. In this case, the trajectories are calculated forwards (start at time step 0) and backwards (start at the last time step) in location and time. The second option can be used to determine a protection zone around a well (e.g. 50-day limit). Time markers can be set on the path lines, which can then be used to construct isochrones.

After successful export, the path lines can be displayed using the plotter.

Batchfile for the output of pathlines