Re: Approximation of non-axisymmetric geometry

["jflrlk" <jflrlk@xxxxxxxxx>]

Hi,

I have a very similar situation, I would like to know the solution 
too. 

The motor we have is bascically axisymmetric, except that the 
polarities of the surface mounted PMs around the rotor are 
alternating, and there exists epoxy between every two adjacent PM 
blocks. Does anybody know how I can model these PMs by an equivalent 
axisymmetric case?

Thanks a lot!


--- In femm@xxxxxxxxxxxxxxx, "niallcaldwell" <niall.caldwell@xxxx> 
wrote:
> Hi all,
> 
> Firstly thanks to David Meeker for writing such a great program- I 
was
> using ANSYS for years, writing scripts for parametric optimisation 
of
> solenoid valves. It is very powerful but a complete pig to use. I 
> have moved to femm because it is so much quicker to set up and 
change
> geometry. The inclusion of Lua means it is just as good as ANSYS for
> most design optimisation.
> 
> My question is not really femm-specific, but maybe some of you have
> tackled it before...
> 
> I have a mainly axisymmetric solenoid valve. The moving pole in real
> life has radial slits in it (for non-magnetic reasons) leaving it 
only
> 50% solid in places. I am wondering what the best way is to
> approximate this non axisymmetry.
> 
> One thought I have had is to define a new steel, based on the B-H
> curve of 1006 but with the B values divided by half (making sure 
that
> the final gradient equals mu0). I would use this new 50% steel over
> the slitted area. By building a library of 30%, 50%, 70% etc. steel 
I
> could model the slitting percentage across the radius of the moving
> pole by dividing it into zones of different material.
> 
> I suspect there is a fatal flaw in this somewhere.... anyone got a
> better idea (apart from 3D modelling that is!)
> 
> thanks
> 
> Niall Caldwell