Point Probe Panel

Frequently Asked Questions

Why should I use the Point Probe panel?

The Point Probe panel will return the exact scalar and vector quantities at any location within the current dataset. This will enable you to examine boundaries for proper boundary conditions, find exact values of temperature and pressure on the leading edge of a wing, or within a vortex, or verify the accuracy of a solution by comparing experimental data to the computational data at the same location.

How do I probe in the modeling window?

To probe a location in the modeling window, simply move the mouse to position the cursor in the modeling window over the location you wish to probe, and press the Ctrl key and left-most mouse button (Ctrl-M1). The X, Y, and Z coordinates will be displayed on the Point Probe panel, as well as the I, J, K coordinates (for structured datasets) and the values of the variables currently loaded into the function registers, at the specified point. You can probe in the modeling window as long as the cursor is positioned over an object in the modeling window, such as a computational surface, iso-surface or streamline. If you click on empty space or an invalid object, such as a legend or title, a "beep" is sounded and the point is not probed.

How do I probe a specific X, Y, Z location?

To probe a specific X, Y, Z location, you can type in the desired location on the Point Probe panel, and click Calculate. At this point, the values for the desired point will display on the Point Probe panel. If the point you selected is not contained within the computational grid, an error message will be displayed.

How do I see the location of the point I have probed?

When a point is probed interactively, a temporary marker will display in the modeling window. This marker will remain until the next modeling window refresh. If a permanent marker is required, or a marker is needed for typed in locations, turn on the Display Point option on the Point Probe panel. This will leave a marker in the window until Display Point is turned off or the panel is exited.

How do I move/rotate the model?

When Select Point is on (default is off), you will be able to probe interactively in the modeling window without holding down the Ctrl key on the keyboard. However, the transform controls will be disabled. In order to use the transform controls to move or rotate an object, turn Select Point off. You can then turn move the model so that the area of interest in visible.

What is the difference between the Point Probe and the Surface Probe on the Computation Surface panel?

The surface probe, on the Computational Surface panel, is used to probe specific I, J, and K coordinates. As a result, it is only available for structured grids, and will only return the scalar value at a specific I, J, K location. The point probe lets you probe anywhere in a structured or unstructured dataset, and will return up to three scalar values and one vector value at the probe location.

How can I create a file based on the point probe output?

If the Output To File option is turned on, you will be prompted for the name of an output file for the results of the point probe. As long as the Output to File option remains on, the results of all subsequent point probes will be written to the specified file. The output will consist of the X, Y, Z coordinates, and up to three scalar and one vector function as shown on the panel itself. This file may be read into the Line Plot panel using the Import option. In that case, the variable that was in the scalar register at the time of the probe will be the vertical axis of the plot. Output to File is forced off and the file is also closed if the panel is exited.

If I already know the X, Y, Z coordinates, can I use them as input to the point probe?

Using the Point Probe Input option, a file of X, Y, Z coordinates may be input. AcuFieldView will then output these X, Y, Z coordinates as well as the currently loaded registers at these locations. The format of the input file is for each point, the X, Y, and Z coordinate should be located on one line, with each point on a separate line. The output file is identical to the input file except it will have four entries per line, with the fourth entry being the scalar quantity. The output file is named pprobe.out. The output file will be created in the directory in which you are running AcuFieldView. Note that it will overwrite it without telling you if there is already a pprobe.out file in that directory and you have the proper file permissions. The Point Probe Input is located in the Restart Files menu.

Why does AcuFieldView "beep" when I try to probe?

When using the interactive probe, you must click M1 on an object in the modeling window that belongs to the current dataset. If you click on empty space or an invalid object, such as a legend or title, a "beep" is sounded and the point is not probed.

Why does the scalar quantity returned by the probe differ from the one displayed on the surface where I probed?

The values returned by the point probe are the scalar and vector quantities currently loaded into the function registers. For example, if you create one surface displaying pressure, and then a second surface displaying temperature, then probe on the first surface, the value of temperature will be returned, not pressure. This is because temperature is currently loaded into the function register. To help avoid confusion, the names of the variables are displayed as well as their values.