COMSOL Natural Convection Thermosyphon Convergence Problem

[Conwedge]

Hello,
I am having some problems with COMSOL multiphysics 3.5a. I am using 2D weakly compressible flow with general heat transfer and am trying to model a natural convection loop.

The Approach I have taken is to use properties of the material for a certain range of temperatures to model the variations in density with temperature which are responsible for the natural convection loop.

I have got the model working only for very small temperature difference (1degK) but above this temperature difference the model goes haywire. I was wondering if anyone has any insights into this problem.

 

[johnsims]

Hello,
I am having some problems with COMSOL multiphysics http://www.3gcgroup.com/index.php/contact/careers" 3.5a. I am using 2D weakly compressible flow with general heat transfer and am trying to model a natural convection loop.

The Approach I have taken is to use properties of the material for a certain range of temperatures to model the variations in density with temperature which are responsible for the natural convection loop.

I have got the model working only for very small temperature difference (1degK) but above this temperature difference the http://www.3gcgroup.com/index.php/contact/careers" problem.

Are you sure you should be using 2D weakly compressible flow? I feel like you should be using something else. Did anyone figure this out!? THANKS

 

[cammin1124]

Hello,
Im having some problems with COMSOL multiphysics 3.5a. I am using 2D weakly compressible flow with general heat transfer and am trying to model a natural http://www.3gcgroup.com/index.php/contact/careers" loop.

The Approach I have taken is to use properties of the material for a certain range of http://www.3gcgroup.com/index.php/contact/careers" temperatures to model the variations in density with temperature which are responsible for the natural convection loop.

I have got the model working only for very small http://www.3gcgroup.com/index.php/contact/careers" problem.

Yeah i had the same problem/ I think the material temperature is off with the variations in density.