[Z.N.A]

Hello everyone,

I'm trying to do a thermal comfort analysis but I have some convergence issues.

What is the reason for k and epsilon to be this way?

Thank you in advance,

[NickFL]

When you see something like that for a steady simulation, it could be it is it is finding an unsteady solution and cannot converge to a steady solution. See the periodic nature in the oscillations? It is likely for your problem the mesh is much too coarse overall or in an important area where recirulation can occur. I would take a look at your results and see if they make sense and where I could improve/refine the mesh.

[Z.N.A]

Originally Posted by NickFL

When you see something like that for a steady simulation, it could be it is it is finding an unsteady solution and cannot converge to a steady solution. See the periodic nature in the oscillations? It is likely for your problem the mesh is much too coarse overall or in an important area where recirulation can occur. I would take a look at your results and see if they make sense and where I could improve/refine the mesh.

Hello NickFL,

I tried to solve the case with k-omega, SST and the residauls was not like this. However, it went down until 10-5 and it's not decreasing after that point.

Mesh Quality:

Minimum Orthogonal Quality = 7.76772e-02

Maximum Aspect Ratio = 2.26209e+02

and you can see how it looks like from inside.

[NickFL]

The mesh does not look too bad there. What about other areas with the seats? Is air being released from the vents? Those are the more critical areas. I see oscillations in all the residuals, which leads me to think there is some kind of shedding going on somewhere.



I would not be concerned about the residuals of k & \epislon, especially if \omega converged well with the SST. Instead, I would be more worried about why the continuity is not converging better. Do you have an explanation for that? Also try moving over to the Coupled solver, that may help force these down a couple of orders of magnitude.