[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
RE: [femm] periodic boundary condition problem
great!!1..thanks!
Juan
enp enp
wrote:
> Hi,
>
> It depends on your problem. If you
would like to
> nalyse no load. You may just model one pole or
1/2
> pole span of the PM machine.
> If you analyse the on load
operation. you would need
> to model at least one pole ans set the
anti-periodic
> conditions at the azimutal boundaries.
> You can
also model two poles you must set in this case
> the periodic conditions
on these boundaries.
> On the radial boundaries in the all cases set
Dirchlet
> conditions, set the the vector potentiel to zero
A=0.
>
> Riyad
Another issue that the original poster may
have is how to apply these
boundary conditions within the program. Unlike
"regular" boundary
conditions, which can be applied to as many different
arcs or segments
or combinations thereof, the periodic boundary conditions
are special in
that they can only be applied to either two line segments
or two arc
segments, and each component of the pair of segments or line
segments
must have the same length. For example, if the edge that
you wanted to
make (anti)periodic was composed of 5 line segments, you'd
have to
define 5 (anti)periodic boundary conditions and apply one to each
of the
segments on the edge and its mate on the adjoining
boundary.
Perhaps all of this would be clearer with an example.
I've attached
pole's worth of a four pole PMSM (which is actually cribbed
from
Quickfield's Magn4 example). Antiperiodic boundary conditions are
used
so that only the one pole need be modeled. I've defined all the
parts
in the rotor to be in group number one, so that the rotor can be
turned,
if desired.
Dave.
--
David
Meeker
dmeeker@xxxxxxxx
http://femm.berlios.de/dmeeker
Your
use of Yahoo! Groups is subject to the Yahoo! Terms of Service.