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No mesh on domains

Posted 23 déc. 2021, 12:53 UTC−5 6 Replies

SUsan
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Dear All,

I have actually meshed all the domains but when I computed, it showes Warnings in sol1 of study, saying "No mesh on domains 1-18 in the meshing sequence with tag mesh1. This may lead to incorrect results." and at the same time there was an error massage "Failed to find a solution. Singular matrix.

There are 686454 void equations (empty rows in matrix) for the variable comp1.T. at coordinates: (0.0881393,0.0371038,0.2286), (0.0881813,0.0374595,0.21717), (0.0881953,0.037578,0.208026), (0.0817499,0.0359305,0.212598), (0.0854638,0.0384823,0.2286), ...

and similarly for the degrees of freedom (empty columns in matrix). Returned solution is not converged. Not all parameter steps returned. "

I just use heat transfer module.

Thank you so much!

6 Replies Last Post 24 déc. 2021, 22:01 UTC−5
Jeff Hiller COMSOL Employee

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Posted: 3 years ago 23 déc. 2021, 13:31 UTC−5

I have seen people think that they had meshed domains when they had only meshed the domains' boundaries. Check if that may be what you've done. If not, please post your .mph file.

Best,

Jeff

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Jeff Hiller
I have seen people think that they had meshed domains when they had only meshed the domains' boundaries. Check if that may be what you've done. If not, please post your .mph file. Best, Jeff
SUsan
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Posted: 3 years ago 23 déc. 2021, 21:39 UTC−5
Updated: 3 years ago 23 déc. 2021, 22:19 UTC−5

Hi Jeff,

Thank you so much for your quick reply.

Yeah, I have changed to another method to mesh and it seems to work.

My model is a 3D model. Before, I used mapped with three boundaries distributed (x,y,z), but now I use mapped one face (x,y) with swept (z). Then, there is no error.

Thank you!

Regards

Susan

Hi Jeff, Thank you so much for your quick reply. Yeah, I have changed to another method to mesh and it seems to work. My model is a 3D model. Before, I used mapped with three boundaries distributed (x,y,z), but now I use mapped one face (x,y) with swept (z). Then, there is no error. Thank you! Regards Susan
Jeff Hiller COMSOL Employee

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Posted: 3 years ago 24 déc. 2021, 09:19 UTC−5

Glad I could help. Good luck with your work .

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Jeff Hiller
Glad I could help. Good luck with your work .
SUsan
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Posted: 3 years ago 24 déc. 2021, 10:22 UTC−5

Glad I could help. Good luck with your work .

Hi Jeff

Thank you！ But now I met another trick, should I creat a new discussion?

That is when I plot a 2D line graph, I set temperature T as Y axis, and for the x axis, I want to set an dimensionless parameter (=arc length/chord). I chose Expression and when I entered "s/c"(default unit "1"), it shows what isn't I expect. Then, I tried "s2" (the description shows it is a surface parameter) though I actually don't know what it means, it seems close to what I want but not correct as well. Then, I tried "s2/c" (default unit changed to 1/m), there is a little change in the line graph and nearly the same to "s2" case. Last, I tried "s2/c1"(c1 has been defined as a global parameter) but the error says c1 has not been defined yet.

P.S. my model is 3D airfoil and the chord length is 914.44mm.

So could you help me to tackle this, please?

Thank you very much.

Regards,

Susan

>Glad I could help. Good luck with your work . Hi Jeff Thank you！ But now I met another trick, should I creat a new discussion? That is when I plot a 2D line graph, I set temperature T as Y axis, and for the x axis, I want to set an dimensionless parameter (=arc length/chord). I chose Expression and when I entered "s/c"(default unit "1"), it shows what isn't I expect. Then, I tried "s2" (the description shows it is a surface parameter) though I actually don't know what it means, it seems close to what I want but not correct as well. Then, I tried "s2/c" (default unit changed to 1/m), there is a little change in the line graph and nearly the same to "s2" case. Last, I tried "s2/c1"(c1 has been defined as a global parameter) but the error says c1 has not been defined yet. P.S. my model is 3D airfoil and the chord length is 914.44mm. So could you help me to tackle this, please? Thank you very much. Regards, Susan
Jeff Hiller COMSOL Employee

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Posted: 3 years ago 24 déc. 2021, 12:02 UTC−5

Yes, please create a separate thread since this is unrelated.

Jeff

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Jeff Hiller
Yes, please create a separate thread since this is unrelated. Jeff
SUsan
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Posted: 3 years ago 24 déc. 2021, 22:01 UTC−5

Yes, please create a separate thread since this is unrelated.

Jeff

Okay, will do, thank you!

Susan

>Yes, please create a separate thread since this is unrelated. > >Jeff Okay, will do, thank you! Susan

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