Search found 32 matches

by frankst
Mon 12 Jun 2017, 10:32
Forum: Development
Topic: B-H loops / Hysteresis
Replies: 3
Views: 7270

Re: B-H loops / Hysteresis

Hi Thorsten,

Just for reference, I stumbled upon this:
https://accelconf.web.cern.ch/accelconf ... PAT040.PDF
It seems that in principle hysteresis can be modeled in FDTD codes.
Obviously, I have no clue how much work the implementation would be in openEMS.

Cheers
Frank
by frankst
Sat 10 Jun 2017, 21:16
Forum: Development
Topic: B-H loops / Hysteresis
Replies: 3
Views: 7270

Re: B-H loops / Hysteresis

Hi Thorsten, Thank you for the answer. I already suspected that this would be difficult. Without having studied the topic in detail, my guess would be that a simple functional relation would be possible (by adapting properties for every time step) but pretty speed limiting. Hysteresis is certainly a...
by frankst
Wed 07 Jun 2017, 10:24
Forum: Development
Topic: B-H loops / Hysteresis
Replies: 3
Views: 7270

B-H loops / Hysteresis

Hi Thorsten, Do you believe it would be possible to implement "realistic" B field <-> H field relations, e.g. to simulate saturation of magnetic materials? While full B-H loops, i.e. with hysteresis, would be most welcome, I guess these would be difficult to implement. May be simpler (and still help...
by frankst
Mon 05 Jun 2017, 21:37
Forum: Usage
Topic: Which hardware for openEMS?
Replies: 24
Views: 27010

Re: Which hardware for openEMS?

Hi Thorsten, To get another data point I ran my test simulation on one more computer. This time it's a Linux (openSUSE Leap 42.2) machine running openEMS 0.0.34 (the others I used before were Win10), i5-4570 up to 3.6GHz, 2x 4GB DDR3-1600. Assuming that the difference Linux vs Win10 is irrelevant. A...
by frankst
Mon 05 Jun 2017, 08:53
Forum: Usage
Topic: Which hardware for openEMS?
Replies: 24
Views: 27010

Re: Which hardware for openEMS?

Hi Thorsten,

I removed the field dumps, but performance did not change significantly.

Since you say memory bandwidth is the limit, I would expect that fast DDR4 RAM and a CPU with four memory channels would be a proper choice.
Do you agree?

Cheers
Frank
by frankst
Fri 02 Jun 2017, 16:54
Forum: Development
Topic: B Field dump
Replies: 9
Views: 14224

Re: B Field dump

Hi Thorsten,

Just to confirm:
All B field dumps that I obtained until now are within expectation (I do see some minor deviations, but those I address to insufficient meshing).
That means, I consider the B field dumps correct.

Cheers
Frank
by frankst
Thu 01 Jun 2017, 21:53
Forum: Usage
Topic: Which hardware for openEMS?
Replies: 24
Views: 27010

Re: Which hardware for openEMS?

Hi Thorsten, Indeed, I read in other threads that CPU is not the limit. But I am still surprised to see the same speed. If memory bandwidth would be the only limit, the computer with DDR3-1600 should have been faster then the notebook with DDR3-1333, shouldn't it? I will test if fields dumps are an ...
by frankst
Thu 01 Jun 2017, 10:07
Forum: Usage
Topic: Which hardware for openEMS?
Replies: 24
Views: 27010

Which hardware for openEMS?

Hi Thorsten, A the moment I run openEMS on a five year old notebook. It has a i5-2410M CPU clocking up to 2.7 GHz and a single 4GB DDR3-1333 SODIMM. I force openEMS to run only two threads because this is the number of physical CPU cores. Since I think of buying something faster, I tried openEMS on ...
by frankst
Thu 01 Jun 2017, 09:08
Forum: Development
Topic: B Field dump
Replies: 9
Views: 14224

Re: B Field dump

Hi Thorsten, Regarding the observed differences at the material transitions, I think the answer is here: http://openems.de/forum/viewtopic.php?f=3&t=405#p2315 Of course, I do not perform the same material averaging as you do. Hence, my results assume different material properties then the ones used ...
by frankst
Tue 30 May 2017, 09:59
Forum: Development
Topic: B Field dump
Replies: 9
Views: 14224

Re: B Field dump

Hi Thorsten, Thank you for the new version. I made some first tests and they look good. Your B field dump agrees within floating point precision with my own B field calculations from H field dumps. There is only a considerable difference at the transition from one material to another (different mue)...