[wilmerecj]

I am simulating the fall of 5 drops of Aluminum on a solid substrate, the model is composed of:
-Gravity
-Heat transfer
-Solidification
-Surface tension
- Viscosity and Turbulence
The control domain is 2×2×3.5 mm

I have the following problem, when the mesh size is up to 6e-5m it works quite well, you can see two drops fall, however when I reduce the mesh size below 5e-5m the drops do not fall directly, the fall becomes unstable.
what could be the cause of the problem?