Electrostatic System with floating conductors

Numerical methods and mathematical models of Elmer
Post Reply
zoot
Posts: 3
Joined: 20 Mar 2017, 16:06
Antispam: Yes

Electrostatic System with floating conductors

Post by zoot »

I have been searching for examples of .sif files showing how to define boundary conditions for floating conductors in an electrostatic system without much success. I have tried setting the surface charge on the floating conductor to zero but results show electrical potential varying over the conductor surface i.e. the electric field tangential to the conductor surface is not zero as I would expect. I have no problem calculating the capacitance matrix.

Does anybody have experience in this area who could explain how to set the boundary conditions correctly? Below is an example of how I set the boundary condition for one of the floating conductors......

Boundary Condition 2
Target Boundaries(1) = 2
Name = "ix0_0"
Capacitance Body = 2
! Potential = 0.0
Surface Charge Density = 0
End

I appreciate any help. Regards, David
raback
Site Admin
Posts: 4812
Joined: 22 Aug 2009, 11:57
Antispam: Yes
Location: Espoo, Finland
Contact:

Re: Electrostatic System with floating conductors

Post by raback »

Hi David,

Look at test case "ConstantBCTemperature". It uses linear constraints to enforce constant, yet unknown, temperature for a boundary.

For electrostatics the BC would be in style,

Code: Select all

Boundary Condition 1
  Name = "floating"
  Target Boundaries = 1
  Potential Constant = Logical True
End
Have fun!

-Peter
zoot
Posts: 3
Joined: 20 Mar 2017, 16:06
Antispam: Yes

Re: Electrostatic System with floating conductors

Post by zoot »

Peter,

thanks for the tip. I'll let you know how it works out.

Regards, David
zoot
Posts: 3
Joined: 20 Mar 2017, 16:06
Antispam: Yes

Re: Electrostatic System with floating conductors

Post by zoot »

This is exactly what I was looking for. Thanks. It's simple when you know how :D
Post Reply