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Hello all:

I am trying to compare the inductance calculation using 4.0a, there's multi-turn coil domain which can output the inductance directly. SO here's the structure, and I will attach my mph file below.

in 2-D axialsymmetry mode, the width of the coil is 0.01m, and lenth of the coil is 0.15m, and coil radius is 0.055m,
THe input current is 1[A], so current density is 1/0.0015 [A/m^2].
In external current density the phi direction current density is set as the value.
in Multi-turn coil domain,the material of the coil wire is sigma=6e7[S/m], number of turns is 15, and coil wire cross-section area is 78.54e-6[m^2], and coil excitation is current=1[A].
The point evaluation for derived value gave the coil inductance as 1.2874e-5[H].

The theoretical result is 0.002*(pi^2)*5.5[cm]*N^2*K/(15[cm]/2*5.5[cm]), and K for (2*5.5/15)=0.7333, is approximately 0.7531, so the analytical inductance is 1.36687e-5 [H].
There's no insulating space considered for the analytical solution.

I just wonder if the set up is correct. There is some error, and I am not sure it's typical the error from the model in COMSOL? Is there anybody can check the procedure?
Ivar, would you please check if it's correct or not? Thanks a lot.


Thanks.