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impeller mixing
Posted 29.06.2010, 15:13 GMT-4 2 Replies
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Hello
Thanks in advance for any help. I'm just starting to learn!
I would like to model impeller mixing in a cylindrical tank. I am starting with a transient 2D model (with the idea of eventually having a 3D model), so the geometry looks like a circle with a cross on the center (the radial impeller). I want to make the "cross" rotate and then analyze the velocity profiles with time.
The density and viscosity are that of water. I am assigning free displacement on the subdomain, while moving the boundaries of the impeller with the equations:
dx = cos(-2*pi*rpm*t)*X-sin(-2*pi*rpm*t)*Y-X
dy = sin(-2*pi*rpm*t)*X+cos(-2*pi*rpm*t)*Y-Y
Meanwhile, from the fliud mechanics side, I need the walls to have a no slip condition. I have tried several alternatives but I keep getting an error message about pointwise constraints not allowed for transient analyses.
I'm very confused.
Thanks again!
Thanks in advance for any help. I'm just starting to learn!
I would like to model impeller mixing in a cylindrical tank. I am starting with a transient 2D model (with the idea of eventually having a 3D model), so the geometry looks like a circle with a cross on the center (the radial impeller). I want to make the "cross" rotate and then analyze the velocity profiles with time.
The density and viscosity are that of water. I am assigning free displacement on the subdomain, while moving the boundaries of the impeller with the equations:
dx = cos(-2*pi*rpm*t)*X-sin(-2*pi*rpm*t)*Y-X
dy = sin(-2*pi*rpm*t)*X+cos(-2*pi*rpm*t)*Y-Y
Meanwhile, from the fliud mechanics side, I need the walls to have a no slip condition. I have tried several alternatives but I keep getting an error message about pointwise constraints not allowed for transient analyses.
I'm very confused.
Thanks again!
2 Replies Last Post 06.07.2010, 14:37 GMT-4
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Posted:
1 decade ago
Hi
it not obvious from what you saying, without the model to catch what is wrong, but I believe this exist as a full mdoel description in one of the docs, or was it on one of the models on the web ?
You ahve an excellent approach to start in 2D its much easier (but still not always obvious ;), before attacking 3D
Have fun Comsoling
Ivar
it not obvious from what you saying, without the model to catch what is wrong, but I believe this exist as a full mdoel description in one of the docs, or was it on one of the models on the web ?
You ahve an excellent approach to start in 2D its much easier (but still not always obvious ;), before attacking 3D
Have fun Comsoling
Ivar
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Posted:
1 decade ago
Hello Ivar
Thank you so much for your reply. I did see a paper from one of the Comsol conferences by Grosz, 2005, where he used momentum source modeling. Is this the model you are referring to? I haven´t been able to find anything else.
Thank you,
Sylvana
Thank you so much for your reply. I did see a paper from one of the Comsol conferences by Grosz, 2005, where he used momentum source modeling. Is this the model you are referring to? I haven´t been able to find anything else.
Thank you,
Sylvana