Numerical Investigation on a Compact Heat Exchanger Partially Filled with Metal Foam

In this paper a numerical investigation has been accomplished to study the thermal and fluid dynamic behavior of a tubular heat exchanger partially filled with metal foam. The Darcy – Brinkman - Forchheimer model and the local thermal non-equilibrium hypothesis (LTNE) for the thermal energy are used to execute two-dimensional analyses on the aluminum foam heat exchanger. The heat exchanger is studied for several air flow rates and a fixed temperature on the surface tube. The results are shown in terms of heat transfer rate and pumping power. Furthermore, the ratios in terms of heat transfer rate and pumping power are given for the two different configurations (partially and totally filled) in order to find the most convenient scheme. Furthermore, the temperature and pressure fields are evaluated. a comparison among the different thickness of the metal foam between two adjacent tubes and the fully filled configuration is given. The results show that the smaller value of metal foam thickness is characterized by a better performance.