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Hi Artem

You need to add to your model tree a node "Force Calculation" under "Magnetic Fields" and select
the regions you want to compute the torque. Then after solving there is a
global variable for forces and torque.


In the hel look for
AC/DC Module > The Electric Field Interfaces > The Electrostatics Interface
which is applicable also in the magnetic case


Cheers

Jens

Hi

Thanks for the reply. I've calculated the torque, but when I do Global Evaluation I can choose Axial torque, Torque x, y, z components. So I always get ZERO for all torques, except torque z component, but I don't understand what is this torque mean and this torque much bigger than I calculated it analitically. As I understand z axis in 2d models mean length (depth) of the motor, but I needed the torque that lies on the x-y axes. Also z torque doesn't depend on lenght of the motor, I have length in Global Definitions, but I think I must somehow make torque depending on legth. I also tried to change Torque axis and Torque rotation point, but z torque changes when Torque rotation point much bigger than diameter of the rotor. How can I find a normal torque?

I attached my model.

Thank you in advance,
Artem

Hi

that looks nice, the forces are high but that is also for a 1m long (deep in Z) device, so 12 N/cm is not that much, or ?

Check your depth in the main physics node.

A few comments: why not add the shaft to the magnetic iron domain and give it some mu_r > 1, also I often check my action/reaction forces hence also measure the force of the complementary parts (stator in your case).

The best force/torque values are obtaines when the part is fully surrounded by air (or the same material) I noticed only a few N difference if I add the air all around so its not really significant in your case. but dor the rotor, I would add the axis too if you add it to the magnetic domain.

Last thing, if you want to get a better mesh in tha thin air gap, add a circle with an inner boundary splitting the air in the middle of the gap and have some 4 nodes over the gap. You can then also use this boundary as a rotating one, in Geometry Assembly mode

Force/torque values are very sensitives to the mesh, I have often noticed that using "boundary mesh" can improve the values, to be tested carefully

Nice model

--
Good luck
Ivar

Hi

Thank you very much Ivar. I've computed the torque and everything looks correct.

Cheers
Artem

Hello Artem Polunin,
Your work is great!
I was wondering, if you can tell me how did you do your Tables?
How did you enter Column and Header to the Tables (Table 1 and Evaluation 2D)?
And how did you find the torque?

Hello Artem Polunin, can you attach your programm file with the torque?