Particles penetrate when using mDBC in a model placed at non-integer multiple positions of dp
I used mDBC to get more accurate pressure results.But I found there're some particles penetrated the boundary.These particles have large velocity and lead to inaccurate pressure results .
I changed some parameters to find the reason,and found it's because the cylinder was placed at non-integer multiple positions of dp.
In the case "examples\mdbc\07_WavesCylinder",the dp is 0.02,the default cylinder's x position is 2.2.And the result is normal.But when I changed the cylinder's x position to 2.205,the particles penetrate from the cylinder's bottom.
I would like to know if this issue can be resolved by adjusting the parameters or other measures.
As you said, non-integer can be a problem if mDBC is adopted.
In your case, coefh values lower than 1.2 can help to prevent particle penetration. However, it may reduce the accuracy, since the smoothing length is small.
You need to check in how many layers your boundaries are discretised... you should have enough to fill "2h" distance
If yes, then you can use DDT=3