# Motor electromagnetic excitation force comparison in Maxwell 2D

Dear all,

Glad to join the community.  I would be very grateful if someone can help me with this time.

I want to compare two motors' electromagnetic excitation (to evaluate motor's noise and vibration). I know we can compare the torque ripple and radial electromagnetic force(Please correct me if I am wrong).

But I don't know how to obtain the radial force in Maxwell 2D.

After some research in google, there may be three ways :

First one,  force parameter way:select the stator and assign force in parameters before calculation. Then there will be a force_x and force_y in results. (But what's the meaning of this force? Can I use this force to obtain radial electromagnetic force? And how?)

Second one, maxwell stress tensor way: Define the formula in field calculator, then calculate the stator's radial force by  integration along the stator's sideline.

Third one, edge force density way: select stator's sideline then assign edge force in field results. (What's the  meaning of edge force density? How to use edge force density to compare two motor's electromagnetic excitation? What's the relationship of edge force density and parameter force?&nbsp  Cheers.

• As given by johnfides in another problem.

try this

for eddy current solution;

Quantity > B Loads the B vector

Function > Phase > OK

Complex > At Phase

Geometry > Line > `edge of your material `> OK

Unit Vector > Normal

Dot

Quantity > H

Function > Phase > OK

Complex > At Phase

Multiply

Quantity > B

Function > Phase > OK

Complex > At Phase

Quantity > H

Function > Phase > OK

Complex > At Phase

Dot

Number > Scalar > 0.5 > OK

Multiply

Geometry > Line > `edge of your material` > OK

Unit Vector > Normal

Multiply

Neg

Scal? > ScalarX

Geometry > Line >`edge of your material` > OK

Integrate