One of the best ways to get value out of your simulation is to do parametric analysis. With very little marginal work a completed model can be parameterized to simulate scenarios limited only by your computational time and resources (have you considered a Parametric Pack for parallel design solves?). With ANSYS R18’s promise of digital exploration, DesignXplorer is now included with all CFD, Mechanical and Multiphysics bundles. Sophisticated parametric exploration, optimization and robustness is now at your fingertips. While ANSYS Workbench and DesignXplorer manage your parameters in a consistent interface, setting up a parameter is different in each of the software tools and not always obvious. This document is intended to be a quick reference of how to do so, letting you get over this initial hurdle to take full advantage of the promise of Digital Exploration.
Table of Contents (for quick jumping around):
SpaceClaim let’s you create a parameter from almost any operation:
Your parameters show up in the Groups tab.
For more advanced driving dimensions you need to have a dimension on an annotation plane:
DesignModeler has the familiar checkbox to “promote” parameters out to Workbench:
You can create relations between promoted parameters and other dimensions in the model with the Parameters Pane.
With the appropriate associative interface licensed and configured, you can make Workbench aware of CAD parameters.
Be sure to either use the DS or ANS prefix or else ANSYS will ignore your parameter. You can modify this with the Parameter Key property shown above.
In Mechanical, anywhere you see the checkbox can be promoted to a parameter for Workbench to use:
APDL command snippets used in Mechanical can also be parameterized, both as input parameters:
and output parameters (any variable with the Output Search Prefix will be retrieved):
Be aware that APDL command snippets are not units aware!
You can also easily use script files from the older user interface in Workbench, easily. With the Mechanical APDL component, specify the input file (along with supporting files as a reference file) and it will be parsed for all of it’s variables. All that’s left is to specify what’s an output and what’s an input:
In Fluent, most places that you can enter a value will have a dropdown that allows you to specify a parameter instead:
In CFX-Pre you can specify expressions as parameters and use them as inputs in other parts of the model:
In CFD-Post you base parameters off of expressions as well, making sure to use the nice right click menu to help with building expressions:
The user interface is similar enough in these tools so that the same instructions apply. When accessing these from Workbench, a DesignXplorer node is created under the Optimetrics portion of the tree. Optimetrics is an EMAG specific optimization tool that is complimentary to DesignXplorer. In most places in Maxwell and HFSS, enter an identifier instead of a number to automatically create a parameter. Promote it out to Workbench in the DesignXplorer node. In the DesignXplorer node, output variables can be created in the Calculate tab.
Similar to the above, in the user interface where you would normally enter a number, instead enter an identifier preceded by $. Then in the Define Trials dialog, expose the parameter to Workbench.
And that’s it! Remember that the power of an integrating platform like Workbench allows you to have several of these software tools be connected in the same analysis flow. From CAD Parameter interaction to coupled field analysis, it’s all possible. Now go forth and digitally explore your design space!
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