Dear friends,

What is meant by "Free slip" in cfx?? how it differs from "no slip" condition?? PLZ reply.. Thanks in advance..

This is fundamental to fluid dynamics.... If this is not familiar to you I suggest you stop doing CFD work for a while and read a good book about viscous flow!

No slip -> Fluid velocity = 0 at stationary boundary. This is the usual condition for viscous flow at a wall.

Free slip -> Normal component of fluid velocity = 0 at stationary boundary. Tangential component of velocity can have any value.

The extension to moving boundaries is obvious: you consider velocity relative to the boundary and apply the rules above.

HTH,

Andy.

Hi,

normally a no-slip condition is used in viscous flow calculation. If u are simulating a non-viscous fluid (for example an Euler flow) at the boundary u have that the fluid velocity is not zero. Anyway also in case of viscous flow u can have a slip boundary condition, for example in rarefied flow (e.g. high altitudes...)...

ok?

cheers

J

Thanks friends...

[mohamad3564]

Hello

I study gas- liquid bubble column. and I use free slip boundary condition for gas base on previous study. I want to understand why I have to use this
boundary condition for gas.
Thank you.