Hi.
I'm trying to simulate a fluid through a vertical channel, width = 0.2 cm - height = 60 cm - fluid == water - inlet v = 1, using the 2D model in COMSOL. Due to the characteristics mentioned a turbulent model is needed. When choosing Algebraic YPlus method the no-slip condition in the vertical walls states (u,v) = (0,0), which is what I thought, but when using the k-epsilon or k-omega model for de NO-SLIP condition (u,v).(nx,ny) = 0 [u = 0 and v is free] which i don´t understand why. Can anyone explain why in k-e or k-omega don'y use velocity=0 on the walls?
Thanks in advance
I am not sure what you exactly mean, but (u,v).(nx,ny) = 0 means that there is no penetration into the wall, that is, the velocity is parallel to (nx,ny).
Hamed Keramati Thanks for your answer. The thing is that when selectiing a no slip condition for the k-e, this no-penetration condition is indicated. I thought that (u,v) = (0,0) was going to be applied such as in other models included in the software.
In the COMSOL documentation the no-slip BC is indicated to be (u,v)=(0,0).
What you described is slip condition. You can consult the COMSOL team for more clarification. You can also run a test simulation to see how the code performs.
- Badges
- Science topic