Hi,
I am Patricia and I am a new Comsol user.
I am modelling the cooling scenario of a low voltage AC drives.To simplify the calculations and to obtain easier results, I have carried out many approximations: air flows between two parallel and vertical plates ignoring the different elements between both plates, box at the top left which dissipates heat and a fan in the bottom of the device which produces the cooling, hence, there is forced convection.
I was modelled on the example of "Convection Cooling of Circuit Boards". I solved 2 days ago and I obtained the temperature and velocity graphs. However, today I wanted to solve again (I didn't do any modification) and I have the next error:
" Failed to find a solution.
Singular matrix.
There are 27 equations giving NaN/Inf in the matrix rows for the variable mod1.u.
at coordinates: (0.00973619,0.290431), (0.013152,0.296094), (0.0114327,0.298224), (0.017299,0.290132), (0.0218176,0.283247), ...
There are 27 equations giving NaN/Inf in the matrix rows for the variable mod1.v.
at coordinates: (0.00973619,0.290431), (0.013152,0.296094), (0.0114327,0.298224), (0.017299,0.290132), (0.0218176,0.283247), ...
There are 28 degrees of freedom giving NaN/Inf in the matrix columns for the variable mod1.T.
at coordinates: (0.00973619,0.290431), (0.013152,0.296094), (0.0114327,0.298224), (0.017299,0.290132), (0.0218176,0.283247), ...
There are 17 degrees of freedom giving NaN/Inf in the matrix columns for the variable mod1.u.
at coordinates: (0.013152,0.296094), (0.0114327,0.298224), (0.017299,0.290132), (0.0218176,0.283247), (0.0226893,0.295827), ...
There are 17 degrees of freedom giving NaN/Inf in the matrix columns for the variable mod1.v.
at coordinates: (0.013152,0.296094), (0.0114327,0.298224), (0.017299,0.290132), (0.0218176,0.283247), (0.0226893,0.295827), ...
Returned solution is not converged. "
I checked so many times everything and I cannot find the errors. Btw, how is it possible to have an error if I didn't modify anything??
Also, I modelled the 3D model of my device (it was modelled on the example of "Convection Cooling of Circuit Boards" as well) and also I have an error
(this time different):
" Failed to find a solution
Divergence of the linear iterations.
Returned solution is not converged
-Feature: Stationary Solver1 (sol1/s1)
-Error:Failed to find a solution. "
I have attached both simulations (the 2D model attached is with the temperature and velocity graphs done, but if you compute again, you will be able to observe the matrix error). I attached them because I think it will be easier to find the error.
If you can clarify my doubts I will be really grateful to you.
Thank you very much for your help.
Sincerely,
Patricia.
I am Patricia and I am a new Comsol user.
I am modelling the cooling scenario of a low voltage AC drives.To simplify the calculations and to obtain easier results, I have carried out many approximations: air flows between two parallel and vertical plates ignoring the different elements between both plates, box at the top left which dissipates heat and a fan in the bottom of the device which produces the cooling, hence, there is forced convection.
I was modelled on the example of "Convection Cooling of Circuit Boards". I solved 2 days ago and I obtained the temperature and velocity graphs. However, today I wanted to solve again (I didn't do any modification) and I have the next error:
" Failed to find a solution.
Singular matrix.
There are 27 equations giving NaN/Inf in the matrix rows for the variable mod1.u.
at coordinates: (0.00973619,0.290431), (0.013152,0.296094), (0.0114327,0.298224), (0.017299,0.290132), (0.0218176,0.283247), ...
There are 27 equations giving NaN/Inf in the matrix rows for the variable mod1.v.
at coordinates: (0.00973619,0.290431), (0.013152,0.296094), (0.0114327,0.298224), (0.017299,0.290132), (0.0218176,0.283247), ...
There are 28 degrees of freedom giving NaN/Inf in the matrix columns for the variable mod1.T.
at coordinates: (0.00973619,0.290431), (0.013152,0.296094), (0.0114327,0.298224), (0.017299,0.290132), (0.0218176,0.283247), ...
There are 17 degrees of freedom giving NaN/Inf in the matrix columns for the variable mod1.u.
at coordinates: (0.013152,0.296094), (0.0114327,0.298224), (0.017299,0.290132), (0.0218176,0.283247), (0.0226893,0.295827), ...
There are 17 degrees of freedom giving NaN/Inf in the matrix columns for the variable mod1.v.
at coordinates: (0.013152,0.296094), (0.0114327,0.298224), (0.017299,0.290132), (0.0218176,0.283247), (0.0226893,0.295827), ...
Returned solution is not converged. "
I checked so many times everything and I cannot find the errors. Btw, how is it possible to have an error if I didn't modify anything??
Also, I modelled the 3D model of my device (it was modelled on the example of "Convection Cooling of Circuit Boards" as well) and also I have an error
(this time different):
" Failed to find a solution
Divergence of the linear iterations.
Returned solution is not converged
-Feature: Stationary Solver1 (sol1/s1)
-Error:Failed to find a solution. "
I have attached both simulations (the 2D model attached is with the temperature and velocity graphs done, but if you compute again, you will be able to observe the matrix error). I attached them because I think it will be easier to find the error.
If you can clarify my doubts I will be really grateful to you.
Thank you very much for your help.
Sincerely,
Patricia.