13.4. Probe

Probe in CFD-Post enables you to determine exact variable values at specified points within a domain.

  1. Select Tools > Probe or click Probe  , or right-click an object in the viewer and select Probe Variable.

    The Probe tool appears at the bottom of the viewer.

  2. You can manually specify the probe coordinates in the Probe At fields or select a point in the viewer.

    If Probe only this variable   is not selected, the probe variable will be automatically chosen. (For example, Temperature will be selected if you select a point on a plane that is colored by Temperature).

  3. The probe variable can also be selected manually from the variable list.

  4. If the desired variable does not appear in the list, select Other... and choose the variable from the Variable Selector.

  5. If Probe only this variable   is selected, the probe variable will not change automatically when new coordinates are entered.

  6. Select Hide Probe tool   to close the Probe tool.

    The probed value appears in the box adjacent to the variable list and automatically updates every time a new coordinate or probe variable is selected.

If you probe on a Point object, the probe position will use the position coordinates of the Point object, not necessarily exactly where you chose.

Note:

  • The Probe tool returns a conservative, not hybrid, variable value derived from volume, not surface, data.

    For example, if you select a location on a surface that is colored according to a hybrid value, the conservative value returned by the Probe tool does not necessarily match the value indicated by the color.

    For details, see Hybrid and Conservative Variable Values.

  • Probe locations will be selected more accurately when you zoom in tightly on the probe location when picking in the viewer. The smaller the object in the viewer is, the less accurate the picked location will be. A consequence is that you may get an undefined value on an outer boundary because the point location will be slightly outside the domain. This problem may disappear if you zoom in on the boundary and probe again. The Edit > Options > CFD-Post > Interpolation Tolerance setting controls the distance by which a point can fall outside a domain and still acquire data from that domain. For details, see CFD-Post Options.