The Mechanisms for Heat Transfer
The Heat Transfer in Pipes interface (), found under the Heat Transfer branch () when adding a physics interface, solves a temperature equation for a fluid transported in a pipe. The physics interface requires the fluid velocity as input, provided either by the user or by coupling to the Pipe Flow interface. However, it is advisable to instead use The Nonisothermal Pipe Flow Interface which is a multiphysics interface that combines Pipe Flow and Heat Transfer in Pipes to model the velocity, pressure, and temperature fully coupled.
The Heat Transfer in Solids, Heat Transfer in Fluids (general convection and conduction, nonisothermal flow, and conjugate heat transfer), and Joule Heating interfaces all belong to the COMSOL Multiphysics base package. See Heat Transfer in the COMSOL Multiphysics Reference Manual for more information.
Coupling to Other Physics Interfaces
It is often relevant to couple heat transport in pipe networks to heat transfer in the region surrounding the pipe network. Simulating the cooling of a mold is a good example of such an application. The Heat Transfer in Pipes interface or the Nonisothermal Pipe Flow interface can be used to model the removal of heat in the cooling channels represented by 1D edges, and couple that heat loss to a 3D model of the mold. The pipe heat model is automatically coupled to the 3D surroundings.
More extensive descriptions of heat transfer, such as 3D turbulent flow models or problems involving surface-to-surface radiation, can be found in the Heat Transfer Module. Furthermore, some cases that involve geothermal applications with groundwater flow models for porous media are better handled by the Subsurface Flow Module.