June 1, 2019 at 8:10 pm #249
I am trying to model heat flows from small resistive elements through thin films and foils and found your tool to be ideal for quick and accurate analysis of different materials and thicknesses. I am targeting dimensions in the micron range however and I have found that when I set a dimension below 0.00005 (50 microns) it resets to this value.
Is there any way of using smaller dimensions?June 3, 2019 at 7:19 pm #252
I will look into this. I didn’t expect users who would use this at micron scale.June 4, 2019 at 3:31 pm #253
Many thanks Charles, yes it seems to be a very handy tool for looking at miniature sensor assemblies. I’d imagine electronics packaging and thermal interfaces could also use smaller measurements.
I’m sure it would be possible to scale the physical dimensions and the material properties accordingly to model the behaviour – it would be good to keep the numbers true to real life though.June 4, 2019 at 7:33 pm #254
I am just back from running a workshop. I will find some time to change the lowest dimension allowed in the program. Thanks for your encouragement!June 5, 2019 at 3:01 pm #255
This is done. See the attached image.
Attachments:You must be logged in to view attached files.June 5, 2019 at 3:03 pm #257
PS: Don’t forget to set the time step to be small to be compatible with the micron scale. Otherwise you will get a fatal error.June 6, 2019 at 11:22 am #258
That’s great, thanks for the quick resolution to this! I’ll give it a try on the heated films and let you know how it goes.
JamieJune 6, 2019 at 4:44 pm #259
I had a quick go at creating thin features and ran into another dimensional constraint. In retrospect this may actually have been the initial limitation I saw. It seems that the minimum dimension is constrained as a fraction of the view window – it looks like dimensions below 1/100th of the window size can not be set.
Previously I didn’t modify the zoom-level so I didn’t see the lower bound changing.
I have attached a screen-shot where I zoomed to a window of around 0.6mm; then setting the thickness to below around 6 micron will reset it to this value. I can probably work with this but ideally I would be modelling strips a few mm long and down to a few micron thick so a bigger range would be useful.
Note, I am using V3.0.3 which the latest version which I could install via the Windows installer.
Attachments:You must be logged in to view attached files.June 6, 2019 at 5:31 pm #261
That is right. Since the computational grid is 100×100, you can’t set the size of a component below 1/100th of the size of the window. If you could, it would be ignored by the engine.June 6, 2019 at 7:04 pm #262
Ok, understood. I presume there is no way to expand the grid-size?June 7, 2019 at 4:09 pm #263
Expanding the grid size would cause the simulation to slow down by N^2. So this is currently locked. But I agree there should be such an option in the future.June 7, 2019 at 7:06 pm #265
Ok, I found a temporary workaround anyway. I didn’t realise that the aspect ratio does not need to be 1:1 so I used a 1mm range in the Y axis giving foil thicknesses in 10 micron increments and a 10 mm range in the X axis for the longer features. This allowed for testing of some different foil arrangements and was useful for optimizing the sensor assembly.
I might be pushing the boat out by requesting another feature but a material library would be good – I found it a bit tedious to enter all of the thermal parameters when switching between foil materials, if they could be entered once and then selected from a list it would speed things up a lot.
Thanks anyway, this is a great tool which I will continue to use.June 7, 2019 at 7:11 pm #266
Many users have requested supporting a material library. Unfortunately, I have very limited time and I am maintaining this software in my spare time. It is not funded by anyone since about five years ago.
Hopefully it will continue to exist.
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