Data for further nucleation

dendritic solidification, eutectics, peritectics,....
CharMIC
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Re: Data for further nucleation

Post by CharMIC » Sun May 10, 2020 7:18 pm

Ohh.. I have completely misunderstood the seed density model upto now. :) Now its clear.

CharMIC
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Re: Data for further nucleation

Post by CharMIC » Mon Jun 01, 2020 11:22 am

Hi Bernd,

in the seed density model if I understood correctly, the seeds will be placed at the beginning of the simulation. so does this guarantee that we will get the distance between the placed seeds will be at least equal to the shield distance?

BR
Chamara

Bernd
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Re: Data for further nucleation

Post by Bernd » Tue Jun 02, 2020 10:23 am

Hi Chamara,

Yes, the potential seed positions are placed at the beginning of the simulation without taking care about the shield distance. However, at nucleation time, the shield distance between seeds of this type and with seeds from other seed types are checked in the same way as for other nucleation types.

In many cases when you want to have a physically "pure" seed density model, additional shielding between the potential seeds is not needed and also not wanted. Then, you should use a shield distance of 0. However, if e.g. the phase is already present due to other seed types (e.g. at interfaces) the user may wish prevent nucleation close to these area. This is the reason why the shield distance is requested also for the seed density model.

Bernd

CharMIC
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Re: Data for further nucleation

Post by CharMIC » Tue Jun 02, 2020 12:05 pm

so if one wants to define nucleation sites that is at least have certain distance between them at the beginning of the simulation what should be the path to take.

what I want is to guarantee that all my nucleation points will have a certain distance (which I can define) to each other.

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

Re: Data for further nucleation

Post by Bernd » Tue Jun 02, 2020 3:01 pm

Hi Chamara,

There is no way assuring a minimum distance of potential nucleation points - it would also be difficult to implement that, because it would not be compatible to freely choosing a radius-seed-density distribution.
However, if you set the proper shield distance and a very long shield time, you should essentially get what you need.

Bernd

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