When running FLACS simulations, you often want to obtain the resulting flow-field data, for example pressure, on surfaces in the simulation domain. You can achieve this by defining monitor panels at these locations and specifying which variables you want to have output there. Monitor panels work very much like monitor points, but allow to measure average quantities on a deck or wall rather than point values.
Inactive panels are defined on the wall to measure the overpressure during an explosion. CASD highlights the selected panel with a white frame.

Add monitor panels

To add a new monitor panel,

  1. go to the CASD scenario menu,
  2. find the Pressure relief panels section,
  3. press Add.

Double-click the panel (or press Edit) to enter the panel’s position and size. Leave the Type as Inactive: this setting determines that the panel is for monitoring purposes only.

Where to place monitor panels

Specify panels such that they match the grid, either by adjusting the grid or by modifying the panel. Otherwise, Flacs automatically adjusts the edges of a panel to the closest grid line.

Verify monitor panels

You can check the monitor panel locations, sizes, and orientations in CASD. Panels are not visible in Flowvis.

Select output variables

Select the output variables to be written for a monitor panel by editing the panel in CASD. If you want to edit several monitor panels at the same time, mark them and click Edit. Typically, you would like the same set of variables to be output at all monitoring panels; you can achieve this by selecting all monitor panels, right-clicking and selecting Edit in the context menu. When editing panels, you can choose one or several variables by left-clicking or dragging.

Which variables to output

The names of the variables available on panels are prefixed by P, for example PDRAG for the dynamic pressure on a panel. The most commonly used output variable for panels is the pressure, PP.

Output frequency and file

Flacs writes monitor point data to the scalar-time output file (r1-file, e.g. r1000000.dat3) once every MODD time steps (default: MODD=1, i.e. every time step). You can set MODD in the Simulation and output control section of the CASD scenario menu, or in the scenario file (cs-file). Normally you want the panel output often, e.g. in every time step for an explosion simulation, while 3D field data is sufficient to have much less often.

Related articles

The handling of monitor panels is very similar to monitor points; therefore, the following articles can also be of interest:

Advanced topics covered in the user manual