multiphysics couplings

Hi everyone,

I have a question about multiphysics couplings.

Now I am doing a water cooling project and I need 2 physics fields: (1)heat transfer in both solids and fluid;(2) laminar flow .

After reading the users guide(P638), I see there is an example "with a Heat Transfer (ht) interface for heat transfer in fluids and a Laminar Flow (spf) interface, you can select Velocity field (spf/fp1), which the Fluid Properties (fp1) node in the Laminar Flow branch defines, from the Velocity field list."
However, in this example, they do not mention about whether we should select Temperautre( ht/fluid1) in the Fluid Properties node under the Laminar Flow branch or not. Does that mean this choice can't affect the result?

And,for my case, I also have a heat transfer interface for heat transfer in solids, should I select "Temperature (ht/solid1)" in the fluid properties of Laminar Flow,or just leave it as "User defined"?

Thanks and Best Regards.