[sylvain.m]

Hello everyone,


I’m new on Ansys and I’m simulating a rectangular cylinder in 2D and the purpose is to find the same local heat transfer coefficients as the experiment.

I have read a lot on this place and on the internet but I can’t understand well yet how to set a good mesh and chose the good model. I read about the Y+ value and I try to get a fine mesh.
I have a Y+ between 0,08 and 0,3 (I plotted it on Fluent after my first simulation). It is <1 so it supposed to be good with the kw-sst, but it give bad results. (50% error rate and the coefficient profile is not good)

I also read that people use ke RNG or ke Realizable but i learnt that they are not really made for calculating in the viscous sublayer, how do people correct that problem, is it about enhanced wall function, or something else? I read that for ke models the first cell must be around Y+=20, is it right ?

What is the difference between kw-SST and Transition SST (4eqn) ?

I would like to know what solutions I can use to get good results and why.

I’m sorry to ask such questions when many threads are about it, but i’m still stuck here.
Thank you very much.


Sylvain