Heat transfer coefficients for solid ceramic sponges – Experimental results and correlation

Abstract

In this contribution, experimental results about heat transfer coefficients for different ceramic sponges (variation of material, porosity and pore size) are presented. A strong influence of the superficial air velocity and of sponge type properties on the heat transfer is observed. The experimental data is correlated with a Nusselt–Reynolds approach as it is usually done for heat transfer data. Furthermore, the applicability of the analogy between heat and momentum transfer – similar to the Generalized Lévêque Equation for packed beds or heat exchangers – is shown. A Nusselt–Hagen correlation has been developed allowing an easy and accurate estimation of heat transfer coefficients for any sponges from pressure drop data. This kind of correlation based on experimental results obtained for many different sponge types is not yet reported in literature.