# How big is the gap using mDBC?

Hello!

Usually the gap using DBC was about "h" in size, but it seems like there is still a minute gap between particles using mDBC?

The reason I think so atleast is that when I probe velocity of fluid in Paraview, I see that a no-slip condition is not fulfilled:

So I assume some very small gap must stil be occuring?

Kind regards

## Comments

How much is the gap as a function of dp? How do you measure this gap?

The distance between fluid and boundary limit should be about dp/2 and distance between fluid and boundary particles should be about dp. This distance would not be a gap since it is the normal distance.

Best regards

In addition note that the new mDBC wil be released in v5.0 next month will include several slip modes.

However we are still working on that and we will only release the robust ones while others will remain for next release version 5.2.

We will explain all this in the documentation as clear as possible.

What case are you trying to simulate?

Regards

Oh yes, that makes sense that if the particles are spaced with dp, then nothing is wrong.

@Alex what I was simulating was wave generation and then I wanted to measure velocity in paraview - this is where I found this "problem", with trying to implement a complete no slip condition.

Kind regards