[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

# Re: line integral and antiperiodic BC

- To: femm@yahoogroups.com
- Subject: Re: line integral and antiperiodic BC
- From: "David Meeker" <dcm3c@aol.com>
- Date: Fri, 15 Jun 2001 15:58:26 -0000
- In-reply-to: <20010614141913.10044.qmail@nwcst336.netaddress.usa.net>
- User-agent: eGroups-EW/0.82

    Ack--this is one of those sort of annoying bugs, because I can't
    duplicate it on my installation--I get the same result in all 3 cases.
    I think what is happening is that, in your installation, the
    program is deciding that points that are on the boundary are
    actually just outside of the boundary. The B.n integral works by
    just taking the difference of the values of A at the endpoints of
    the contour, so if you get an A=0 from a point that it thinks is
    outside your geometry, that would explain the difference in reported
    values.

    Anyhow, I'll look into this and see if there is some way that I can
    make this more robust...

    Dave.

    --- In femm@y..., <vecerkaj@u...> wrote:
    > Hi everybody
    > I've met the problem with simple line integral calculating the total
    flux and
    > average Bn. I posted example, where the situation occured. It
    presents a PM
    > synchronous machine (only half of machine, used antisymetric BC)
    > When I chose the contour for the calculation of average Bn over one
    rotor pole
    > in the airgap (see example.gif) I realized, that the result depends
    on the
    > way, how I selected a contour for the calculation.
    > 1. When the startpoint is selected inside of the region and endpoint
    is on the
    > boundary (antisimetric BC), the result is Bn1=0 (nonsense).
    > 2. When the startpoint is selected on the boundary, and endpoint is
    inside the
    > airgap, the result of line integral is certain value Bn2=nonzero.
    > 3. When I choose the contour arbitrary (by right button of mouse) in
    the
    > similar location and I obtain the different value of the Bn3
    (Bn3=2*Bn2).
    >
    > It seems, that correct value of Bn is the value Bn3. But I expected
    the same
    > values obtained by different ways(except sign).
    >
    > If anybody interested, I included also fem file. Maybe I make all
    the time
    > same stupid mistake, can anybody show me the right way or a reason
    of
    > differences?
    >
    > Note the example uses linear characteristic of iron, just because of
    > computation speed (in reality I use nonlinear BH characteristics).
    >
    > Thanks in advance
    >
    > George Vecerka
    > Department of power electric and electronic
    > Faculty of Electrical Engineering and Computer Science
    > Brno University of Technology
    > Czech Republic
    >
    >
    > ____________________________________________________________________
    > Get free email and a permanent address at
    http://www.netaddress.com/?N=1

- Follow-Ups:
  - Re: line integral and antiperiodic BC
    - From: vecerkaj@usa.net

- References:
  - line integral and antiperiodic BC
    - From: <vecerkaj@usa.net>

- Prev by Date: line integral and antiperiodic BC
- Next by Date: Re: [femm] line integral and antiperiodic BC
- Previous by thread: line integral and antiperiodic BC
- Next by thread: Re: line integral and antiperiodic BC
- Index(es):
  - Date
  - Thread