You can easily couple the Pipe Flow Interface with single-phase flow interfaces using the multiphysics coupling feature Pipe Connection ().

The Pipe Connection multiphysics coupling couples a 1D pipe segment modeled with the Pipe Flow interface with a 3D domain modeled by a single-phase flow interface. This coupling is available when the 3D fluid flow is simulated using laminar flow or RANS-EVM turbulent models.

Select Heat Transfer and Heat Transfer in Pipes interfaces to model nonisothermal pipe connection.

Select the boundary that corresponds to the inlet/outlet of the 3D model coupled to Pipe Flow interface.

Select a Fluid Flow interface and a Pipe Flow interface to couple fluid flow. Heat Transfer and Heat Transfer in Pipes are optional. They can be set to None when the coupling is used to simulate isothermal flow.

There is an automatic search for possible adjacent geometrical objects. If you want to modify the selections, select the Manual control of selections checkbox. If you clear it, the selections will be replaced by the automatic ones.