Papers presented to the 11th International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics, South Africa, 20-23 July 2015.
Heat sinks made out of open-cell aluminium foam are
investigated numerically in natural convection. Results derived
from a 2D numerical model are compared to results for in-house
experiments. Different foam heights are studied. The numerical
model is based on the volume averaging theory. The aluminium
foam that is used has 10 pores per linear inch and a porosity of
93%. The temperature of the substrate was varied between 55°C
and 95°C. The geometry used in the numerical model replicates
the experimental test rig as well as possible. A discussion of the
determination of the closure terms is given.
If only convective heat transfer is taken into account in the
numerical model, the relative differences between the numerical
and experimental results are smaller than 29% for all foam
heights studied. However, when the influence of radiation is
included in the numerical model, it is shown that the numerical
results differ less than 9% with the experimental ones. This
validates the choice of closure terms used in the model and this
shows that it is necessary to properly model radiative heat
transfer in numerical models of open-cell aluminium foam in
natural convection.
