This heat exchanger example illustrates the multiphysics modeling capabilities of FEATool. The model consists of a series of heated pipes surrounded by a fluid at a lower temperature, and features effects of both free and forced convection. Two types of physical phenomena are considered, fluid flow which is modeled by the Navier-Stokes equations, and heat transfer modeled by a convection and conduction transport equation for the temperature. This system features a two-way multiphysics coupling, the fluid is coupled to and transports the temperature field, and the temperature is also coupled back to the fluid via the Boussinesq approximation accounting for buoyancy effects.
Due to symmetry one can simplify the full geometry and only study a two dimensional slice between the heated pipes. The geometry will therefore consist of a 0.0075 by 0.05 m rectangle from which a half circle with radius 0.003 m centered at (0, 0.02) is removed. The mechanism for heating the pipes is not taken in consideration and are thus assumed to be at a fixed temperature of Th = 330 K. A cooling fluid flows from the bottom to the top and has an inlet temperature of Tc = 300 K. The other fluid and material parameters can be found in the model tutorial.
This model is available as an automated tutorial by selecting Model Examples and Tutorials… > Quickstart > Heat Exchanger from the File menu, and also as the MATLAB simulation m-script example ex_heat_exchanger1. Step-by-step tutorial and video instructions how to set up and run this model are linked below.