A study of flow and heat transfer characteristics in real and ideal anisotropic foams

Abstract

Porous foams are commonly utilized materials in thermal protection systems. In this work, an ideal Kelvin foam with pore-scale characteristics identical to those of the real foam was constructed and a comparison for the two structures was performed. Results demonstrate that compared with the real foam, the ideal foam exhibits higher pressure drop and peak velocity compared to ideal foam due to the rapid change in the cross-sectional area. The pressure drop across the skeleton is the lowest when the flow is along with the stretching direction, and the anisotropic characteristics become increasingly prominent with increasing inflow velocity. The region of most intense heat transfer occurs at the windward side of the skeleton. At high incoming flow velocity, the ideal foam presents better coupling between the temperature and velocity fields, resulting to a better heat transfer performance than the real one.