Generalized projective method to compute forces in the Import / Export data context

A new method called Generalized projective method to create force collections is available in Flux 2021.2 in the Import / Export data context. This kind of collection allows to compute forces on a generic mesh (i.e., a set of points) with the aim to be exported to OptiStruct to setup a NVH analysis of electrical devices, such as rotating machines. This method and then the collection created may be seen as an extension of the Simplified projective method dedicated to rotating machines previously named Force collection dedicated to rotating machine.

This approach is based on two data supports defined by the user: one for the data collect and secondly a set of supports to integrate and compute magnetic pressure to be exported. The support to collect the data must be imported with the help of the data supports as it is shown in (b) part of the figure below. The set of supports to integrate and compute magnetic pressure can be defined by an extruded compound path, a 2D grid as shown in (a) part of the figure below or an extruded geometric line in an air region. All the components of the magnetic pressure are computed with the Maxwell tensor approach on the set of supports and finally they are projected on the support for the data collect.

Figure 1. Axial flux motor in Flux 3D: (a) the support - created from a 2D annular grid - to integrate and compute the magnetic pressure, (b) the support - imported from OptiStruct - to collect the data

Several applications for NVH analysis of axial flux motors, electrical machines with no-cylindrical air gap or eccentricity studies are now possible. For more informations about this new feature, see its dedicated documentation by typing in the dedicated search engine of the Flux user guide the keyword: Generalized projective method.

As an example, with the new force data collection obtained by this Generalized projective method in 3D it is now possible to compute axial forces while using a surrounding box composed of 2D grids (cylindrical and annular) around the moving part as show below:

Figure 2. Computation of axial forces over a rotor of a permanent magnet synchronous machine: (a) the surrounding box composed of 2D grids, (b) the imported OptiStruct mesh.
Note: The support to compute and integrate the magnetic pressure shown in (a) part of both figures above must be adapted to the device geometry to get accurate results.