Mass Concservation in Two Phase Pipe Flow

Hi folks,

I was wondering if there is a way to check if the mass conservation principle is uphold in COMSOL for pipe flow.

I am using glass spheres in water in my simulation and due to some instabilities I have employed some Inconsistent Stabilization, and I am fearful that this might mess with the mass conservation.

Any advice?

Best Regards,

Rui