MixSim2: How can I implement an impeller as a new object?
I want to implement a new impeller object in MixSim.
I have an ACIS file that can be used in the "Custom by ACIS file" impeller object, by I want
- to have a particular button for this particular impeller, and
- to see some preview graphics for the impeller. (See "Resolution" no. 2 of this Solution..!)
When an ACIS file for the impeller exists, and has proven to work fine in the "Custom by ACIS file" impeller import object, you can turn this into a new object by the following procedure:
- Find the file "Impeller-Geom-Custom.mxo" in the directory ".../Fluent.Inc/mixsim2.0/Mixsim-Object-Library".
- Copy (not move!) it into a safe location. Rename it to something different (no matter what).
- Edit it using a text editor that doesn't add any text formatting information to the file(!):
- In the List of parameters, find those that you don't want the user to have access to any more. These will most probably be the name of the ACIS file, the "Nom. Diam. (in file)" parameter, and perhaps the hub dimensions. For all these parameters, set the proper values in the "Value:" line, and change the "Hidden Parameter" line from "No" to "Yes" (retain capitalization of the first character!).
- Also (and important!), change the "Name" setting in the very top of the file (this is what will be displayed in the MixSim GUI. You may also change the "Class" setting to something different, so that the impeller will be listed in a different group of impellers, BUT (IMPORTANT!) the value that is assigned to the "Class" setting MUST contain the character string "mpeller"! (E.g. as in "My own Impellers".) You may NOT modify the "SubClass" setting!
- Place the edited file and the corresponding ACIS (.sat) file in the directory .../Fluent.Inc/mixsim2.0/Mixsim-Object-Library, or in your User Object Library directory (and remember to set that properly in MixSim BEFORE your create a new model).
- If you want to add the newly define impeller type to an existing model, there may appear additional problems as described in the Release Notes. When encountering those problems (button for the new object doesn't appear in the GUI), you should consider creating the model newly from "scratch", in a new MixSim session, after having set the User Object Library Directory variable if needed. Note that this setting is saved in the Defaults file.
Please do also check Solution no. 911 -- it gives you some help when you want to add your new impeller to an existing model.The preview graphics for Custom impellers (and those that have been derived from the Custom impeller object in the previously described way) can be defined in the object file. This requires scheme coding, and using internal scheme commands for the displaying of graphics primitives. There are two impeller object files in the release file set that demonstrate this:
- The "Cust. Grph. Smpl. PBT" -- this is a conventional Pitched Blade Turbine with the preview graphics defined in the object file (and thus overriding the hard-coded default preview graphics for the PBT). The file is Impeller-Geom-GrphSmPBT.mxo. Compare the file to Impeller-Geom-PBT.mxo in order to find the relevant sections and contents.
- The "Parametric Sample". This example shows even how a completely user-defined impeller can be defined when no ACIS file is available, but the geometry can be put together by a series of Gambit commands. The file name is "Impeller-Geom-GnrcSmpl.mxo".
The preview graphics section of this file is identical to the one in "Impeller-Geom-GrphSmPBT.mxo" and will thus create the preview graphics display of a PBT, although the geometry that is built in Gambit for this "Parametric Sample" impeller is completely different. (The user is told so by a particular warning that is displayed during mesh generation.)
There are some more internal scheme commands available for creating graphics primitives than those used in the sample (template) files mentioned above. These can be found in the source code file "msgraphics.scm". In case of special needs, please submit a help request.