1.3.3. Physics Message Window

As you work through your simulation, CFX-Pre continually checks the physics definitions you have specified. Whenever an action is carried out, the physics validator runs a check on the CCL definitions of all the objects created up to that point. Physics checking is carried out by comparing the current CCL data against library files such as RULES, VARIABLES and PHYSICS, which are known to contain only valid physics specifications. If an inconsistency is found in the physics, the object with associated error(s) is highlighted in red text in the tree view.

In addition to object name highlighting, the physics validation window displays all error types in the simulation: global errors, physics errors and expression errors. The output in this window gives an explanation of each of the detected errors. Double-clicking on a red item or a maroon item (an expression error) in the physics validation window will take you to the correct place in order to edit the object.

Global errors apply to the entire simulation and show errors that are not specific physics errors. Often these errors show required objects that need to be defined to complete the simulation (for example, initial conditions or a domain). They also show invalid referencing of regions in a simulation. In some cases, the global errors offer a suggestion rather than being a definite error. For example, if you have created two valid boundary conditions on one region, a global error will be shown (despite the fact that the physics for both boundary conditions may be correct) because you cannot specify more than one boundary condition on any given surface.

Physics errors (highlighted in red) involve an incorrect application of physics.

  • Global errors appear in blue text.

  • Specific physics errors appear in red text. You can double-click these to edit the object containing the error.

There are two common situations when you are likely to encounter physics errors:

  1. CFX-Pre defines some objects, such as the Solver Control settings, by default. If you create a new object that is not compatible with the default objects settings, the physics validation summary window will show errors in the default object. This occurs when creating a solid domain because the default Solver Control settings do not contain a solid time scale. These errors will disappear when you define the Solver Control settings.

  2. When changing the physics of an existing model. There are many instances where you might want to change the description of your simulation. One particular situation is when you want to use the values in a results file as the initial field for another run with different physics.

    When a domain is modified, perhaps with new model options, you will receive errors or warnings in the physics validation summary window if you need to revisit and update existing boundary conditions, initialization, solver controls, and so on. This happens, for example, when the turbulence model is changed from the laminar model to the model and the boundary conditions for the laminar case do not contain turbulence data (for example, at an Inlet). You should fix any such errors before writing a CFX-Solver input file.

    You should update boundary conditions if the number of Additional Variables has been increased, or if the units for Additional Variable specifications have been changed.

If the simulation is set up correctly, there will not be any physics errors when you are ready to write the CFX-Solver input file.

1.3.3.1. Physics Errors from Old .def/.res Files

When you load CFX-Solver input/results files from previous versions of Ansys CFX, you may receive error messages, despite the fact that the files can be run in the CFX-Solver. This is due to differences in the previous CFX-Solver input files. In CFX-Pre, a more strict approach to CCL structure and content has been implemented to ensure the integrity of the CCL made available to the CFX-Solver.

CFX-Pre performs some automatic updates when opening CFX-Solver input or results files from previous versions of Ansys CFX.

1.3.3.2. Physics Message Window Shortcut Menu Commands

Right-click a message in the physics message window to perform the following functions:

Copy

Enables copying of the selected message.

Edit

Enables you to use the Details View to edit the object generating the error.

Auto Fix Physics

Enables you to attempt to correct inconsistent physics automatically. In many cases, you will find that this fixes the problem without a need to change any settings on the form. Alternatively, you can use the Details View to edit the object generating the error.

Viewing the type of error before performing auto fix is strongly recommended. For example, auto fix cannot fix a domain with an incorrectly specified location. In effect, auto fix opens the default layout of the panel and performs an apply. If you are unsure about auto fix, you should subsequently open the form and verify that the settings are still valid for your problem. You should fix all physics validation errors to ensure that the CFX-Solver input file runs in the solver. If any errors are found when you attempt to write the CFX-Solver input file, a warning message is displayed giving you the option to write the file anyway or cancel the operation.

Auto Fix All

Runs auto-fix on all objects that have physics validation errors.

Suppress this message

Suppress the selected message; a message summary is displayed instead.

Suppress all messages

Suppresses all messages; message summaries are displayed instead. Note that messages generated subsequently will not be suppressed.

Unsuppress all messages

Unsuppress all messages.