Discussion Forum

I have a 3D homogenized multiturn coil model (DC), which has been previously validated for the z component of the magnetic field against a 2D-axisymmetric DC/AC coil model. Now, I have added a shield of certain thickness around this coil and would like to observe the shield loading on the magnetic field component, Hz.. I could not load the solved model in here because of memory restrictions, but I have the geometry. Please mesh it, assign Ti material to the shield and then solve the model to look at the solution. My question however is, how would I now evaluate the inductance of this setup (coil+shield) at 175 KhZ using the frequency domain solution(I know how to setup the frequency domain solution for this but how would you evaluate inductance). Obviously, the shield thickness is lower than the skin depth of Ti at 175 KhZ. Would I have to use the impedance boundary condition at higher frequencies and in order to do that would I have to analytically calculate what this skin depth and respective frequency would be. I know that I am using a homogenized coil model, but would there be a reasonable way to incorporate coil skin effect in here ? For example, since this is a cross-section current excited coil, can I just calculate the magnitude of current reduction because of skin effect and then evaluate the magnetic field based on this new value of coil current. How would this evaluation be different from the actual skin effect phenomena (I am not evaluating the field near the coil boundary). Would there also be a reasonable way to incorporate packing density in here ? How far away in the z direction would I obtain an accurate value for Hz given that I have the airbox extended upto that range. Thanks in advance.

Venkat