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Decreasing Concentration Problem
Posted 17 avr. 2012, 06:48 UTC−4 Version 4.2a 1 Reply
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Hello All,
I'm currently working on a project to model the concentration of certain defects during the growth of a certain crystal using the Transport of Diluted Species interface. I've encountered a problem and can't seem to find a way around it. The concentration of these defects grows gradually and then stops after a certain time. When this concentration stops growing it should be maintained constant through the rest of the simulation. However, when I model the concentration in a 1D plot, the concentration decreases as the crystal grows. I've uploaded a simplified version which shows the problem in a clearer manner, using a gaussian function and a constant velocity which should only move this function in the z-direction. Instead of only moving the function, it also decreases the numerical result. I've tried modifying the mesh, and the problem persisted. I believe that this is a numerical error, any help would be appreciated. Thanks.
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Patricio Davila
I'm currently working on a project to model the concentration of certain defects during the growth of a certain crystal using the Transport of Diluted Species interface. I've encountered a problem and can't seem to find a way around it. The concentration of these defects grows gradually and then stops after a certain time. When this concentration stops growing it should be maintained constant through the rest of the simulation. However, when I model the concentration in a 1D plot, the concentration decreases as the crystal grows. I've uploaded a simplified version which shows the problem in a clearer manner, using a gaussian function and a constant velocity which should only move this function in the z-direction. Instead of only moving the function, it also decreases the numerical result. I've tried modifying the mesh, and the problem persisted. I believe that this is a numerical error, any help would be appreciated. Thanks.
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Patricio Davila
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1 Reply Last Post 20 avr. 2012, 07:04 UTC−4
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Posted:
1 decade ago
Update: I tried solving the same simple problem with the convection diffusion PDE equation, and the results were more stable. However there was still a slight decrease in concentration. I believe this is a numerical error. Has anybody any idea on how to avoid this problem? Thank you.
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Patricio Davila
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Patricio Davila