Multiphysics software speeds resolution of design problems

Features include a powerful analytic tool to help users quickly assess different winding configurations in rotating electrical machines. A new graphical analysis setup tool brings drag-and-drop editing simplicity to complex evaluation sequences involving multiphysics simulation. The modelling of materials with very small skin depths is also made much simpler by a new surface impedance boundary condition for transient electromagnetic analysis; the code for this software is also specifically structured to allow parallel processing to accelerate analysis.

The new tool for electrical machine design can shorten development times significantly, by allowing highly detailed investigation of possible winding options prior to finite element analysis and simulation of the most promising designs. The Winding tool enables designers to assess the feasibility and efficiency of different coil winding configurations, and their impact on machine performance. The software includes a winding wizard which creates a report of all feasible windings for a user-specified range of slots and poles, backed by detailed winding characteristics for each slot-pole combination. It is available for both the two-dimensional and three-dimensional Opera design software packages.

The Opera-3d Modeller now has a graphical tool to simplify the preparation of data for analysis. It provides users with a very convenient means of controlling the sequence of analyses, using drag-and-drop editing to add or remove specific analysis stages to a list. Context sensitivity allows the tool to give instant visual feedback on the validity of requested changes, while the properties and parameters of analysis stages can be adjusted within the tool’s environment. Individual analysis stages can be saved out and used in other sequences to further speed the design process.

The Analysis Setup tool simplifies advanced multiphysics simulation significantly, including transient analyses. Users can now set up a complete chain of electromagnetic, thermal and stress analysis simulations for example, with no limit on complexity or sequence. Loops are allowed and the results from one simulation are passed automatically to the next. Shape deformation caused by forces acting on a model can be employed across different types of simulation; the deformed mesh from stress analysis can be nominated for use in subsequent electromagnetic or thermal analyses. In the case of coils, the software automatically accommodates any changes in current density values due to shape deformation, facilitating very accurate electromagnetic field analysis.

Another major feature in the latest release of Opera-3d is that the scope of the surface impedance boundary condition has been widened and is now available for use in transient electromagnetic analysis, including Demagnetization and Motional Analysis. This simplifies the modelling of materials with a very thin skin depth by replacing the volume elements in a conducting region with surface elements. The variation of fields and currents below the material’s surface is represented by a decaying waveform which models the skin depth.

Version 18 of Opera also consolidates or extends a number of features that were introduced in the previous version of this software. These include the ‘solve as 2d slice’ feature, which is now standard in the Opera-3d Machines Environment. It enables users to evaluate machine performance using a one element thick slice obtained from the full 3d model, with the appropriate boundary conditions applied automatically. Depending on model complexity this can dramatically reduce the number of elements that need to be solved, often by several orders of magnitude, resulting in much faster solution times. There is almost perfect correlation between results obtained from the 2d slice and the full 3d model, and the 2d slice can be converted to 3d to analyse end-effects.

The GUIs of Opera-2d and Opera-3d continue to make increasing use of tabbed menus to simplify operation and many are now backed by keyboard shortcuts. Enhanced context sensitivity means that drop-down menus are much shorter and mainly replaced by menu bar icons, allowing fast, single-click navigation and control. All high-level user interface functions can be displayed in English, French, Chinese and Japanese.

Cobham has also taken the opportunity to further extend Opera’s interoperability. Version 18 extends the optional links previously available to a wider variety of third-CAD packages. These now provide the ability to work with CATIA, NX, Pro-Engineer Creo and SolidWorks files. IGES, Parasolid, SAT and STEP files offer CAD-neutral geometry access.