[Jason94]

Hello friends
I am new to simulating with Ansys Fluent. I have a question about the range of y+ and the turbulency model to be used. I want to simulate airflow inside a spiral channel with constant heat flux on the walls. As I read in the articles, the y+ should be below 1 for heat transfer simulation. On the other hand, for the k-e turbulency model, y+ should be 30 to 300. I want to know what do you suggest for this problem? Which y+ and turbulence model should I take?
Many thanks for considering my request.

[LuckyTran]

In general, lower y+ is always better assuming you use the appropriate wall treatment.

The standard k-epsilon model using specific wall functions should have a higher y+. And frankly, I don't know of anyone that actually prefers this particular asinine combination. Most people use better turbulence models and use the enhanced wall treatment (in other words, an all y+ approach).

If you can afford the lower y+ ~ 1, go for it by all means. It's just better. No one will complain.

[Jason94]

Thank you, LuckyTran, for your answer. I also prefer to deal with y+ lower than 1. For this reason, I used inflation close to the walls to reduce y+. I used the k-omega SST turbulence model. For convergency, I had to use the first-order method for the density and energy; otherwise, the residuals wouldn't reach the proper value (e-3 for continuity, momentum, and turbulence, and e-6 for energy). Do you think my approach is good enough to achieve accurate results?

[somia baali]

i dont know exactelly but i think you must choose Y+=1