mixing two laminar flows of different fluids in the same chamber

Dear all,

I am trying to mix two laminar flows of different fluids within the same chamber in a very simple geometry. In particular, I have two “inlet pipes” converging into a common chamber with an outlet.

Through the first pipe there is an input flow of water whilst the second pipe introduces methanol in the chamber. In both cases the inlet condition is set as a constant mass flow.

Not sure which physics I have to use as to model this. I have already tried including several laminar flows as well as with multi-phase physics but I was not able to obtain relevant solutions.

Any advice in this regard?

Thanks a lot in advance.