Multiphysics: Not Just for Analysts Anymore

By Bob Williams
Product Manager
ALGOR, Inc.
Pittsburgh, PA

Not long ago, multiphysics software was strictly a tool of specialized engineering analysts. Today, more engineers and scientists are using multiphysics software because it is becoming increasingly easy to use. This trend involves several simultaneous advancements in geometry and data exchange technologies, user interface enhancements and direct integration between multiple analysis types. 

The advancements in geometry and data exchange technologies can be seen in the trend toward supporting multiple geometry and data sources. FEA software now provides API-based support for multiple CAD packages in addition to neutral file support and traditional finite element modeling tools. Tight, API-based support for popular CAD packages makes multiphysics FEA software more readily available to design engineers. Scientists and engineers in varying disciplines using industry-specific design tools, such as those in the MEMS or electronics industry, can now transfer their geometry to FEA software through neutral files.  

Some FEA software packages provide the ability to combine geometry from multiple sources. For example, an electronic component from a specialized electronic design package may be imported as a neutral file and merged with the geometry for its housing that was seamlessly captured using API-based support for a CAD solid modeler. 

In addition to geometry, the exchange of other types of data such as experimentally obtained material properties or loading curves may be transferred using standard file formats such as Microsoft Excel or comma-separated value files. 

User interface enhancements support the broader application of multiphysics software by allowing users to focus on the physics of a part or assembly, rather than having to learn the process and terminology of a particular software package or analysis type. A modern graphical user interface should include easy-to-use, Windows-style features such as right-click functionality for loads, constraints and FEA properties, tree views that visually guide users to provide all necessary information, multiple view windows, docking toolbars and context-sensitive menus that are tailored to particular steps in the analysis process. 

The same user interface should serve all available analysis types. Moreover, the geometry and basic information, such as material properties and units, should be stored in a common database shared by all analysis types so that users do not have to do duplicate work in order to look at multiple physical phenomena. 

In order for an FEA package to offer direct integration between multiple analysis types, the package must provide a broad range of analysis types to consider motion, mechanical stress, heat transfer, fluid flow and electrostatics. While having a common user interface to unite all analysis types is a necessity for facilitating multiphysics, it is not the only requirement. FEA software must also provide simple tools for linking one type of analysis to another. 

For example, considering the effect of Joule heating in a model should be as simple as clicking on a few options to link the results of an electrostatic analysis to a heat transfer analysis. This type of multiphysics application is common in MEMS or electronic devices, where the heat generated by a current may be an important influence.

Forced convection is another good example. Engineers performing heat transfer analysis should be able to simply click on an option to include fluid convection effects. Such a method of predicting how flow velocities will affect temperature distribution in both fluid and solid components is especially useful to engineers analyzing systems that require fans or water for cooling and those that transport molten metal or liquefied plastic or rubber, all of which operate at extremely high temperatures. Computer enclosures and heat exchangers are other common applications for this capability.

As these examples clearly show, designers and engineers often need to consider many physical effects when simulating a real-world use case. Improved geometry and data exchange technologies, easier-to-use user interfaces and tighter integration between multiple analysis types are bringing the real world to the desktop. Therefore, more users are avoiding assumptions about the effects of multiple physical phenomena and producing more accurate and comprehensive analyses. This multiphysics simulation approach to optimizing designs reduces expensive and time-consuming physical prototype testing. When parts need to be verified through reduced physical prototype testing, costs and time-to-market are also reduced.