evaluting meshing and velocity profile near the wall
 

Hi
I'm doing a free surface flow CFD modeling project that the velocity and pressure near the bottom (wall boundary) are important parameters. for evaluating the pressure result I have data and after refining mesh I saw that the pressur was not sensitive to it and I reached to a good answer.

but for velocity I do not have any data and just want to reach an answer that not depedent on mesh size.

I use k-epsilon standard in CFX code

so my limitation for y+ is 20 and 100 (CFX help)

• now i'm reaching to y+ under 20 and still my velocity profile near the boundary changes due to make the meshes smaller. what can I do

please help

hi,
i think that you try to create a boundary layer near the surface. So the mesh near the surface is very small. in gambit there is a specific buttom for this. the parameters that you controll is:

1. the first layer
2. the grow parameter
3. the number of layer that compose your boundary layer

i thinck that in this way you can see the profile of velocity near the wall.

thank you so much

if you'd like to consider the secondary flow K-e is not a good model.