Hi,

I would recommend using a Phase Field Equation coupled with Navier-Stokes see the following Paper:Article Numerical Simulation of Wetting Phenomena with a Phase-Field...

You can implement the equations in the PDE Module in Comsol.

Best Regards

It depends which is your final objective. If you want to study the droplet properties, you can use the level set method, moving mesh interface or phase field, along with spf or conjugate heat transfer, depending if you want ti study also the thermal exchange.

Regards

A good way to start a simulation with Comsol is to use a similar solved case from Comsol's website. Then you can change it to what you need.

Using Phase Field with Navier-Stokes will work but keep in mind that in Phase Field method you may loos some mass, in other words Phase Field may have some mass conservation issues.