Convective Air Heat Transfer Through 10 PPI Aluminum Foams

This paper presents the experimental heat transfer coefficient and pressure drop measurements obtained during single phase air heat transfer through four 10 pores per inch (PPI) metal foams with different porosities and different foam core heights, 40 mm and 20 mm respectively. The specimens have been inserted in an open-circuit type wind channel with rectangular cross section. The effect of the foam core height on the heat transfer has been analysed by imposing three constant heat flow rates at the bottom plate of the samples: 250, 325 and 400 W and varying the air mass velocity between 0.005 and 0.025 kg m⁻² s⁻¹ at around atmospheric pressure. The temperatures of the base, of the upper plate and of the air, at the inlet and outlet of the test section, have been measured by means of several T-type calibrated thermocouples. The pressure drops during air flow through the samples are recorded by means of a high accuracy differential pressure transducer. The experimental results are presented in terms of heat transfer coefficient, normalised mean wall temperature, pressure gradient, permeability and inertia coefficient. The measured pressure gradients and heat transfer coefficients have been compared against the predictions of two different models recently developed by present authors.