Pore density effect on a heat exchanger in aluminum foam with flat-tubes

The present paper is a numerical study on a heat exchanger in aluminum foam with flat-tubes. The local volume averaging process is assumed in order to evaluate the microscopic flow equations in two-dimensional steady state regime. The Darcy-Brinkman -Forchheimer model and LTNE condition between fluid phase and solid matrix are assumed. Different geometrical dimensions characterize the flat tube. The foams are examined for an assigned porosity value, equal to 0.90, and different pore density or pores per inch (PPI) values equal to 5, 10 and 20. Several air flow rates are considered in the heat exchanger with an assigned value of the flat-tube surface temperature. The numerical solutions are accomplished by means of the Ansys-FLUENT code. The results are given in terms of pressure drops, between the inlet and the exit of the system, and average heat transfer coefficient, evaluated on the external surface of the flat-tubes. Furthermore, temperature profiles along the median cross section of the heat exchange system are showed. In addition, a comparison with a heat exchanger with a cylinder tube is provided in terms of thermal and mechanical power.