Opera 18

Version 18 & 18R1 & 18R2 of Opera introduced significant new features. These include a winding tool, a tabbed menu interface customisation, a material database and Python extensions. Also included in Opera-3d is an upgraded geometry kernel and CAD interfacing, a multi-physics analysis setup tool, multi-core (parallel) GUI operations, a new 3D mesher, transient surface impedance boundary condition (SIBC) with loss calculations, thin plate boundary condition, prism gap meshing and space charge solution process improvements. There are additional analysis types to the environments, and additional standard features to licensing, and in the documentation there is the Additional Support Knowledgebase (ASK) extension.

To find out more about the benefits of this release, see below:

Winding Tool Diagram

The Winding Tool

The Winding Tool is a new analytical tool that is a separately licensed option which is available both within Opera-2d/PP and Opera-3d/Modeller. Dedicated to electrical machine design, the winding tool helps users assess feasibility and optimality of different winding configurations, and provides users with the following output:

  • Optimal winding layout (circular and linear representation)
  • Stars of Slots representation
  • Winding factor harmonics
  • Winding mmf harmonics
  • GÖrges Diagram

Tabbed Menu Interface customisation

The position of the Tabbed Menu Interface (TMI) can be customised to appear at the top of the screen, or on the left-hand side. The graphical user interfaces can be now used with keyboard shortcuts which have been defined for some of the more commonly used functions. The full list of shortcuts is available in the New Features document.

Figure 1: Hysteresic B-H material data for 0.5 mm laminated Silicon Steel (FeSi 3% wt)

Permanent Magnet Material data

Material data, in the form of BH and Demagnetization data is now provided for a range of Magnequench MQ1 Materials

Python extensions

The $COMINPUT command can now be used with Python scripts (*.py) as well as command input files (*.comi). A new Python function, operafea.currentSimulation().getFieldsAtCoords() returns an OperaObject containing field values at a set of points. This is available in the Opera-3d solvers and Post-Processor. A new Python function, operafea.currentSimulation().stopNlSolver(), can be used to stop nonlinear iterations before convergence in the Opera-3d nonlinear solvers. To enable this function, a new set of solver hooks associated with the start and end of nonlinear iterations has been introduced. In addition, system variables have been made available for the convergence parameters.

Figure 1: Simulated section of the geometry, ¼ of the strip with implied symmetry in zx & zy planes and at z=0 and 2e-4 and zoomed in region of the conductor showing the mesh.

Improved Geometry Kernel and Interfacing

The geometric modelling software used in Opera-3d/Modeller has been upgraded to the latest release, ACIS R25. This provides interoperability with additional CAD formats (licensed) and updates the surface mesh generator. When importing CAD models, if material and part numbers exist in the file, Opera will label the resulting Opera geometry with the references.

Modeller Analysis Setup Tool

A new graphical tool has been included in the Opera 3d/Modeller to prepare data for analysis. The Analysis Setup Tool provides an easy-to-use drag-and-drop interface to the ANALYSISDATA, DBCASEDATA and MULTIPHYSICS commands to prepare a single analysis, or sequence of analyses as part of a multiphysics analysis.

The tool consists of 3 panels:

1. On the left is a list of the analysis types. These can be dragged onto the central panel to be added into the sequence of analyses at any position in the list.

2. The central panel contains the sequence of analyses. This sequence can be altered by dragging additional analysis parts into the sequence (they can be dropped either at the end or earlier in the sequence), or an existing sequence can be altered by deleting analysis parts or SHIFT+dragging them to another location.

3. If an analysis in the central panel is selected, its properties and parameters can be adjusted using the property sheet which shows in the panel on the right.

When the Analysis Setup Tool is closed, the commands necessary to create the analyses with their parameters will be run in the Modeller.

Transient Surface Impedance Boundary Condition (SIBC) with loss calculations

The Surface Impedance Boundary Condition (SIBC) is now available in Transient EM analysis, including Demagnetization and Motional Analysis. SIBC simplifies the modelling of materials with very small skin depths compared to the size of the model. It avoids the need to create very small elements on the surfaces of such materials. The standard post-processing options for force, power and energy apply to conductors that use the SIBC. The fields on the surface of the conductor may be displayed in the post-processor in the usual way.

The power loss calculated in a harmonic or transient analysis using the Surface Impedance Boundary Condition can now be used as the heat input into a thermal analysis in an automated multiphysics sequence.

Thin Plate Boundary Condition

The Opera-3d Magnetostatics solver has a new boundary condition which can be used to represent thin plates of soft magnetic material. When analysing certain applications such as ship signatures and magnetic shields the geometry can lead to aspect ratio problems in the mesh, whereby the area of a feature can be much greater than its depth. Representing this with standard volume elements can lead to either numerical problems in solution or meshing problems in pre-processing. Using the Thin plate boundary condition the feature is represented in the Modeller as a surface. This simplifies the modelling process and provides much faster solution times. In 18R2 the ability to specify a Packing Factor for the plate has been added.

Prism Gap Meshing

The Rotating Motional Electromagnetic solver has been updated with an improved automated remeshing algorithm. If the user creates the topology of the gap region in a way that it qualifies for prism meshing, the new meshing technique will create prism elements in the gap, rather than tetrahderal. Because the meshing with prisms is fast and robust, and requires less elements, the remeshing process will see a big increase in the speed and reliability of the model during analysis.

3D Meshing

There is now a choice of mesh generators in the Opera-3d Modeller. Mesh generator Type II can create tetrahedral meshes in a wide variety of geometries. If the traditional mesher strategy encounters issues during the meshing process, the Type II generator can be used. There are some special cases (e.g. filametrary conductors in circuits and multiple periodicities) for which the new mesh generator cannot yet be used. Mesh generator Type I can handle all those special cases and can also create mixed meshes including hexahedra, prisms and pyramids.
mesh type dialog
Simulating charge particle sources and beams

Space charge solution process improvements

Langmuir-Fry V-I tabulations are now stored in a local database file so that they can be re-used in other analysis runs or other cases in a single analysis. Once a tabulation has been calculated for a particular set of emitter parameters it will not be re-calculated for that emitter type. This can significantly speed up analyses where multiple models are run with identical emitter definitions. The Opera-3d Charged Particle analysis program no longer saves the tracks file at every nonlinear iteration. The previous behaviour can be selected, with other options as well, using the SAVEITERATIONS parameter of the ANALYSISDATA command in the Modeller.

Multi-core (Parallel) GUI operations

The Opera-3d CAD model import (with the LOAD command) now uses multiple threads.

In the Post-Processor multiple threads are used in two types of calculations:

  • Fields from conductors
  • Fields by integration

Helium Airship with braided conductors

Opera-3d Machines Environment

Torque vs. Speed Analysis – A new analysis has been added that evaluates the torque vs. speed profile of permanent magnet and synchronous reluctance machines. The existing analysis for Induction Machines has been extended to capture the complete torque characteristic of an Induction Machine.

Iron Loss calculations for SRMs – The existing iron loss calculations for synchronous machines have been adapted for SRMs in order to accurately account for losses in the machine.

Wound Synchronous Machines – The generator- open circuit (Static) analysis provides a relationship between field current and induced voltage for all load conditions. The generator- short circuit analysis provides a relationship between the armature current and the field current. The generator – load analysis provides information about the generator operating point position in relation to the stability limit.


The existing Opera-2d Direct Sparse Solver option is now unlicensed. This entitles all supported users of Opera-2d to benefit from a shorter analysis time. The interface to Simulink from Opera-2d and Opera-3d is no longer a separately licensed feature. All supported users of Opera on Windows systems now have access to the Simulink interface.

The Additional Support Knowledgebase (ASK)

The ASK has several new articles:

  • Calculation Time of Trajectories
  • Comi-Script with User Interactions
  • Converting $Const-$String-$Const
  • Debugging of Control-Comi-Files
  • Maximum Distance between Sample Rays
  • Parallel Solvers.
  • Conductors – Create your own Shapes
  • Eddy Current Losses in 3d
  • Measured Signals used in Circuit Editor
  • Parallel Solvers
  • Patch method to calculate Forces in 3d
  • Picking by Position
  • Replicating a 3-phase PWM Current Source
  • Using Opera to control Matlab®

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