Add the Pipe Wall Heat Transfer multiphysics coupling node () to create transitions between domains modeled using the Heat Transfer interfaces and edges modeled using the Heat Transfer in Pipes or Nonisothermal Pipe Flow interfaces. The Pipe Wall Heat Transfer adds the source term Qwall (SI unit: W/m) to account for heat exchange through the pipe wall. The source is averaged on a cylinder of the pipe radius around the selected edges. The diskavg operator is used for source averaging around the edge. The coupling also passes the external temperature calculated by averaging the temperature in Heat Transfer interface to Wall Heat Transfer feature in the pipe interface. The circavg operator is used for averaging the temperature across the pipe. The circavg and diskavg operators are used to avoid obtaining an increasing pipe temperature value when meshing finer than the pipe diameter.

The Label is the default multiphysics coupling feature name.

The Name is used primarily as a scope prefix for variables defined by the coupling node. Refer to such variables in expressions using the pattern <name>.<variable_name>. In order to distinguish between variables belonging to different coupling nodes or physics interfaces, the name string must be unique. Only letters, numbers, and underscores (_) are permitted in the Name field. The first character must be a letter.

The default Name (for the first multiphysics coupling feature in the model) is pwhtc1.

By default, the selection of the coupling node is the edges inside the domains selected in the Heat Transfer interface that also selected in Wall Heat Transfer feature in the Heat Transfer in Pipes or Nonisothermal Pipe Flow interfaces.

This section defines the physics involved in the coupling. The Heat transfer in pipes and Heat transfer drop-down menu lists include all applicable physics interfaces.