Learning Forum

[Ashen Perera]

Hi ,

I am doing my final year engineering project on the modelling of a shell and tube heat exchanger , I modelled the heat exchanger and I have meshed it in Ansys mesh. I have a few doubts to clear up as follows: 

I would like to improve my mesh quality i have applied sizing methods on edges , faces of tubes and shells. I have shown the final quality metrics but I want to further improve such as in the points i have shown.

- the mesh i used is tetrahedrons with the element size currently set at 3mm : 

1. I want to improve the mesh metrics further by reducing the maximum skewness value, a few elements are at 0.86 ( i have attached mesh metrics , skewness plot and the elements that have the high skewness )
2. Doubt about the interfaces, in the fluent interface i see src and trg in interfaces , when i unselect the tube walls disappear , I would like to know about this but the walls dont display ( should i make these src and trg interfaces coupled as my heat transfer is from the tube surface to the shell side) 
3. I would like to know about if i need to apply inflation to the tubes . 

Thanks in advance ,

Ashen

[Rob]

Couple of general comments. 

• Why have you modelled the baffles with a thickness? Have a look at the thin wall options in Fluent
• Try and avoid non conformal interfaces, so check multibody parts or share topology options (DesignModeler & SpaceClaim respectively)

[Ashen Perera]

But i need the baffle thickness to be 4 mm , and if i coupled the src and trg would it be fine 

[Rob]

Read the section in Fluent relating to thin (coupled) walls. Setting a nonconformal is OK, but a conformal mesh may be computationally more efficient.