[Jeeloong]

Hi all,

I am quite puzzled. I had various y+ for k-e realizable which is used with DPM and eulerian wall film.

Let begin with

1)y+ approx = 4
2)and y+ approx = 1.6 = 2.3 (Adaptive mesh refinement AMR)
3)Refinement using pre-processor ICEM to obtain y+ = 0.6

So apparently, the wall shear stresses changes with the same model being used. For y+ 4, Enhanced wall treatment. The film thickness is in the same order as that of experimental (paper validation), the same goes to use AMR where the order of film thickness is the same.

However, when further refined to be Y+ <1 to be in the valid range of Enhanced wall treatment which is y+ 1. The film thickness is 4 times higher as the shear stresses changes.

I am wondering is the y+ <1 is invalid for enhanced wall treatment k-e realizable model?

I thought they are insensitive even up to less than 1.

I am looking forward to Menter Lechner and k-w models.

Could someone shed the light.

Thanks

JL

[LuckyTran]

I think you should investigate what's happening with respect to the DPM and eulerian wall film models rather than the EWT and turbulence model. I would focus on the wall film.

[2phase]

Hi Jeelong,

did you get any further with your question? I am working on a similar topic and would like to know if you found an answer.

Thanks in advance
Martin

[Jeeloong]

Hi Martin,

It has something to do with my mistake of not switching on the Gravity. As some physics requires gravity which affects the results tremendously.

I think for most cases where wall shear stresses need to be accurate. resolving down to y+ = 1 or less than that is necessary (eg K-w models)

Kind regards,
Jee