RE: Could you provide the models which are using in the wall slip BC?
I have PIM project in which our experience tells us that the wall slip could play an important roll. I noticed that there are two options in Moldex3D wall slip BC, power law model and friction force method.
Could you provide me the models that are using in these two methods and explain a bit for me that how they affect the wall slip effect?
What is Wall Slip?
Typically, fluid velocity at the wall is assumed to be zero as “no-slip boundary condition” Wall slip occurs when a fluid moves along the wall with a non-zero velocity, Common in polymer melts, highly filled materials, or concentrated suspensions.
What is Critical Wall Shear Stress?
Wall slip starts only when the wall shear stress exceeds the critical value, a threshold value of wall shear stress.
Below this value → No slip occurs (standard no-slip behavior)
Above this value → Wall slip begins (velocity at the wall > 0)
Wall Slip Models in Moldex3D
1. Power Law Model
Based on an empirical slip behavior model (commonly used for polymer melts)
Assumes that wall slip velocity follows a power-law relationship with wall shear stress
2.Friction Force Model
Based on the slip behavior model, but models wall slip as a result of frictional resistance between the wall and fluid
