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
Attachment:
example1.fem
Description: Binary data