Trouble with convergence
 

Hi all,

I am having trouble with converging one of my 2D simulations.
I have attached an image of the geometry and my mesh.
The mesh is very good quality >0.7 and min angle > 18 degrees.

However, when I run it for simple laminar flow, there appears to be a large pressure building up at the corner (see image 'Close Up') and this prevents the system from converging.

Does anyone have any meshing tips on how to improve this mesh so that simulation converges?

Thanks,
Andreas

Hi Andreas,

i would suggest to try to match the element sizes of adjecent blocks. The expansion ratio could be too high.
Have look at the corner at the smallest element in screen 4. On top of the left block, elements seem to be more than 6 times as big as adjacent elements. In sense of numerics, that's a problem. Often it's recommended to maintain an expansion ratio of 1.2 or smaller.

With regards,
Sebastian

Blocking is not good
 

Try some better blocking


http://s25.postimg.org/7zke7oivj/Untitled.png

Hi Bluebase and Far,

Thank you very much for your tips. I will give it another shot.

Regards,
Andreas