Discussion Forum

Hi all,

I'm trying to make an simulation of measuring a coils inductance when a object is moving in it's vicinity. I modelled a 50 winding 3 dimensional coil, 1st in 2d axisymmetrical mode with a solid square cross section and:
n= number of windings
I_tot = Jphi_emqa/n (A) (subdomain integration)
W_m = Wmav_emqa*2*pi*r (J) (subdomain integration)
And calculated the inductance with L = 4*W_m / abs(I_tot)^2
This resembled the real values and also came at the same value as L = imag(V0*n / I_tot)

Now I want to measure the change when a non-symmetric object moves in respect to the coil. For this I revolved the 2D model around the axis. But now I have to find the equations for the current. I set the current density in the coil on:
x y z
-J0*z/sqrt(x^2+z^2) 0 J0*x/sqrt(x^2+z^2)

Now I'm in doubt how I can get the total current density. I was thinking about the normal of both x and z currents:
sqrt(Jx_emqa^2+Jz_emqa^2) and integrate over the subdomain, but that will give a m*A unit. Should I divide this through the circumference of the coil (2*pi*sqrt(x^2+z^2))?
Also I think I can have W_m = Wmav_emqa (integrated over all surfaces).
And my final question: is it possible to get the Loop potential to also calculate inductance with Ohm's law for this case?

Regards,
Michiel
Student Mechanical Engineering