Direct method for volume forces (dFLapV)
Introduction
This chapter discusses the use of the Direct method for volume forces (dFLapV) to create force collections in the Import / Export data context: this kind of collection allows to compute Laplace forces on a volume mesh with the forces density dFLapV.
- Description of the approach
- Creation of this force collection
- Limitations
- Example
Description of the approach
Figure 1. Support defined from the Flux mesh on the secondary coils of a power transformer.
Laplace forces density are created in a region by the interaction of the current density J with the magnetic flux density B such as : dF = J x B . The volume regions with a non-zero current density and magnetic flux density are the following ones:
Creation of this collection
- In the data tree, select the menu Forces data collection
- In the dedicated GUI for Forces data collection, choose Direct method for volume forces (dFLapV)
- Choose a data support to collect the data
- Choose the collection interval:
- Collect for all the steps of the scenario
- Collect only for the current step
- Collect for a specified interval
- Click OK
- Right click on the forces data collection just created in the data tree and run the command Collect data
Example
In this example, the aim is to compute the forces in the winding of a power transformer shown in Figure 1.
We define a support to collect the data: it comes from the Flux mesh and is the same as the one described in Figure 1; it is based on the volumes which are described as coil conductor regions representing the secondary winding of the power transformer. As these parts are subjected to important forces they may vibrate and produce an annoying sound.
Figure 2. Distribution of nodal force densities in the secondary coil of a power transformer.
These forces can also be exported to OptiStruct with the Data export in order to proceed to a NVH analysis of the winding.