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Temperature coupeling

Posted: Thu Aug 06, 2020 11:22 pm
by g.azizi
Hello,
I am trying to simulate simple solidification of one dendrite which nucleate at the center of my domain (please see the attachment). I wanna couple temperature and concentration but I get this error message:
# Flags
# -----
# Type of coupling?
# Options: phase concentration [volume_change] temperature temp_cyl_coord
# [stress] [stress_coupled] [flow] [flow_coarse] [dislocation]
temperature concentration
# Type of temperature coupling?
# Solvers : gs rbgs
rbgs

Input error in routine leseDimension, answer: option concentration can not be coupled to option temperatureconcentration

would you please help me with this? I need to have heat transfer from my all 4 boundaries.
Thanks

Re: Temperature coupeling

Posted: Fri Aug 07, 2020 6:24 pm
by Bernd
Dear g.azizi,

In MICRESS it is not possible to couple to concentration and temperature simultaneously. The reason is that the diffusion length for heat and solute are orders of magnitude apart, and solving temperature on the fine grid required for the dendrite with concentration coupling would make an immense calculation effort. Even then, temperature would be practically flat due to fast heat diffusion, so you simply could use coupling to integral latent heat instead ("lat_heat").

The only way of coupling temperature and concentration simultaneously is by using the "1d_temp" option. With this option, a one-dimensional temperature solution can be calculated on a coarser grid and on a larger domain and coupled to the micro-domain. This allows for micro-macro coupling in cases where a 1d-approximation of the temperature field is possible (see for example here).

Bernd