# Initial particle setup (particle radius and dp)

In the XML guide, sqrt(dx^2 + dy^2 + dz^2) = sqtr(3 dp^2), and h = coefh . sqrt(3 dp^2).

In the initial particle setup, is (dx^2 + dy^2 + dz^2) the particle radius?

....

Using 3D Wendland kernel, there is a unique kernel definition region in which the radius is 2h.

What's the number of particles inside the domain of influence?

Some literature uses the criterion of a minimum number of particles (51, for example). What's this number in DualSPHysics?

## Comments

Excuse-me:

"...is sqrt(dx^2 + dy^2 + dz^2) the particle radius?"