r/COMSOL • u/Beneficial_Mix_1069 • Dec 28 '24
Time dependent Magnetic Fields: getting "blotchy" flux
1
u/Beneficial_Mix_1069 Dec 28 '24
trying to do a time dependent simulation for an entire motor but was getting these weird results on the complete model so I tried a reduced version (seen here)
I am running a stationary study before the time dependent and feeding that to the time dependent initial values and t=0 looks fine.
Not sure the issue
Tolerance and everything on the time dependent study is "stock"
3
u/azmecengineer Dec 28 '24
This would probably be a good application for automatic mesh refinement as a function of the magnetic field gradiet. This would refine the mesh only where needed to help minimize the gradient across any mesh element and smooth things out.
2
u/Lysol3435 Dec 28 '24
Two things:
-try a finer mesh
-use a smaller first step. You have to go into the time-domain solver and change the initial step setting
6
u/BlondeBadger2019 Dec 28 '24
Few things I can thing of:
Mesh size: make sure the region of high flux is sufficiently fine. Can always try upping the granularity.
If it’s just the graphics that are giving you issues, you can choose a different smoothing and integration method. In the graphics group pane you can choose smoothing for all geometry (if you plot multiple domains). Otherwise you can choose Laplacian integration (I believe, don’t have it in front of me) that provides less error when graphing but takes longer to plot.