Learning Forum

[fthdrmss]

I made a design to find the mutual inductance between two filaments. I completed the simulation in a box with air. But when the dimensions of the box change, the mutual inductance value changes. As you can see in the images, 846.13 pF is obtained when the dimensions are 10mmx21mmx32mm, and 1.897 nH when 10mmx40mmx60mm. How can I overcome this problem? Is there a point I missed? Thanks in advance for your answers.

[NKC]

Hi @fthdrmss There are two points to consider here
1) As long as the region is sufficient enough to cover the whole field distribution you should get the same result for anything Region size above that region size.
But if the region is such that it is not fully enclosing the whole magnetic field you will get a difference in results.
For example, if the magnetic fields are well-contained, as in motor, the padding can be 20-50%.However, if the magnetic fields are not well-contained, such as two parallel current-carrying conductors in air, the region padding may need to be higher.
*If the field results change significantly when the region size is changed, the region is not large enough.
2) Mesh quality - Make the mesh finer. IN the initial mesh settings move the slider to right.
Regards Navya