Is it possible to set a input file with end temperature?

technical aspects of .dri file generation (e.g. debug mode ) etc...
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RAGHAV
Posts: 45
Joined: Thu Jul 10, 2008 6:21 pm

Is it possible to set a input file with end temperature?

Post by RAGHAV » Mon Jul 30, 2012 3:37 pm

Hello all,

I would like to know if it is possible to set a alloy simulation with a certain end temperature with temperature intervals rather
than time-steps directly?

I want to see the influence of different cooling rates for Alloy AlCu but keeping the end temperature always same
for the alloy in each simulation. Then at this end temperature i want to compare the average grain size for different cooling
rates.

Regards
Raghav

Bernd
Posts: 1504
Joined: Mon Jun 23, 2008 9:29 pm

Re: Is it possible to set a input file with end temperature?

Post by Bernd » Mon Jul 30, 2012 6:10 pm

Hi Raghav,

Do you mean that MICRESS should make outputs (and also stop) not after given time intervals but after given temperature intervals (e.g. start at 900K, make an output every 10 K and stop at 700K)?
This could be interesting if temperature is calculated implicitly using latent heat, but could also be difficult if temperature is rising...
Do you mean that? This is not yet implemented! Do you think it would be interesting?

Bernd

RAGHAV
Posts: 45
Joined: Thu Jul 10, 2008 6:21 pm

Re: Is it possible to set a input file with end temperature?

Post by RAGHAV » Wed Aug 01, 2012 3:57 pm

Dear Bernd,

Thanks for your answer.

Yes, i mean that. At the moment, i set the time steps and stop the simulations so that i could get a particular end
temperature to make my observations.

Actually, i didn't take the latent heat into consideration for my case but i am going to inculcate it in the near future.

Cheers
Raghav

Bernd
Posts: 1504
Joined: Mon Jun 23, 2008 9:29 pm

Re: Is it possible to set a input file with end temperature?

Post by Bernd » Wed Aug 01, 2012 4:30 pm

Dear Raghav,

what could be done with relatively little effort is to implement the possibility to request an extra output when temperature drops below a given target temperature. At this extra output, the program would not stop, but at least you would have an output for the given temperature for all cooling rates - would this be helpful for you?

Apart from that, I think that latent heat is of great importance in the case of equiaxed solidification! You at least should use global latent heat like it is done in the AlCu_Equiaxed_dri example, which is perfect for small samples ("DTA approximation"). In case of real (big) castings, the best solution is the "Iterative Homoenthalpic Approach" which uses coupling to a 1D temperature field and which I described here:

B. Böttger, J. Eiken, M.Apel, Phase-field simulation of microstructure formation in technical castings – A self-consistent homoenthalpic approach to the micro–macro problem, J. Comput. Phys. 228 (2009), 6784-6795.

I can send you a personal copy on request.


Bernd

RAGHAV
Posts: 45
Joined: Thu Jul 10, 2008 6:21 pm

Re: Is it possible to set a input file with end temperature?

Post by RAGHAV » Mon Aug 06, 2012 8:13 pm

Hello Bernd,

Yes, that would be pretty helpful as an extra output. Please send this paper on

raghav.pasricha@mars.uni-freiburg.de

thanks and best regards
raghav

Bernd
Posts: 1504
Joined: Mon Jun 23, 2008 9:29 pm

Re: Is it possible to set a input file with end temperature?

Post by Bernd » Mon Oct 22, 2012 5:34 pm

Hi Raghav,

the extra output has been implemented in MICRESS and will be available with the next major release (MICRESS6.1)! The keyword "end_at_temperature" followed by a temperature value inside the time imput data loop can be used to define an end temperature. Once this temperature is reached (either with increasing or decreasing temperature), a final output is writtten and MICRESS terminates.

Example:
..
# Time input data
# ===============
# Finish input of output times (in seconds) with 'end_of_simulation'
# 'regularly-spaced' outputs can be set with 'linear_step'
# or 'logarithmic_step' and then specifying the increment
# and end value
# ('automatic_outputs' optionally followed by the number
# of outputs can be used in conjuction with 'linear_from_file')
# 'first' : additional output for first time-step
# 'end_at_temperature' : additional output and end of simulation
# at given temperature
linear_step 0.1 0.5
end_at_temperature 1595.3
10.
end_of_simulation
# Time-step?
...

Bernd

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