Reaching Covergence while decreasing particle size.

[SohailAusgur]

Hi All,

I'd like to conduct a particle resolution study where I decrease the particle distance and record how the values are changing up until they do not change anymore. However, the convergence is not stable. Can someone please explain, how the Smoothing Length relates to the particle distance and how the smoothing length needs to be changed in order to keep the simulation stable and reach convergence.
See Picture below:

It is a simple issue to be resolved.

Many Thanks.