# Forces data collection

Four types of force data collections are available in Flux,
corresponding to specific computation methods and/or approaches:

- The Simplified
projective method dedicated to rotating machines is a computation
method based on Maxwell tensor and dedicated to the most classical
configurations of rotating machines (e.g. without eccentricity); it is an
efficient and robust method based on the evaluation of forces in a virtual
cylinder in the airgap of a rotating machine in order to subsequently
project them on an imported mesh or on a Flux mesh. These values may finally
be exported towards
**OptiStruct**for a**NVH**analysis of the electrical machine. - The Generalized projective method may be seen as an extension of the Simplified projective method dedicated to rotating machines; in fact, if the approach explained above is well adapted for rotating machines with cylindrical airgap, this one allows the user to compute forces on every kind of support that may be defined by an extruded compound path, by a 2D grid or by an extruded geometric line in an air or vacuum region. These force values are then projected, and finally exported, on a previously-imported mesh, with the possibility to have all three spatial components if the physical configuration is suitable (e.g. axial flux machine).
- The Direct method for surface forces (dFmagS) is a general forces computation method at the interface between two materials with different magnetic permeabilities; being generic, it can be applied on every type of face data support.
- The Direct method for volume forces (dFLapV) is based on the integration of the Laplace forces and may be applied on any volume data support. Being these forces generated by an interaction of the magnetic flux density with the current density, this approach is available only for the solid conductor regions and the coil conductor regions.

Type of forces data collection | Computation quantities and points | Export quantities and points |
---|---|---|

Simplified projective method dedicated to rotating machines | Computation of the Maxwell tensor on a virtual cylinder in the air gap of the electrical machine | Projection of the Maxwell tensor on the data support |

Generalized projective method | Computation of the Maxwell tensor on every kind of support that may be defined by an extruded compound path, a 2D grid or an extruded geometric line in an air or vacuum region | Projection of the Maxwell tensor on the data support (imported mesh only) |

Direct method for surface forces (dFmagS) | Computation of dFmagS on the data support | |

Direct method for volume forces (dFLapV) | Computation of dFLapV on the data support |