Experimental and numerical studies of the pressure drop in ceramic foams for volumetric solar receiver applications

This paper presents experimental and numerical studies of the pressure drop in ceramic foams for solar air receiver applications. There are three main aims in this study. The first is to measure the pressure drop in the studied ceramic foams, and to build an empirical model based on the experimental results and a parametric numerical simulation. The second aim is to study flow field characteristics in the ceramic foams, especially in the vicinity of the interface. The third is to study the pressure drop characteristics of two modified structures (by manufacturing holes on the ceramic foams) that are expected to decrease the pressure drop in ceramic foams, but maintain good heat transfer properties. The experimental results from the samples, including two modified structures, along with the simulation results, show that the pressure drop in the ceramic foams follows a modified Darcy relationship. The experimental results also show that the two modified structures dramatically decrease the pressure drop (with pressure drop decreases up to 70% at a superficial velocity of 5 m/s). Based on both the experimental and the simulation results, a generalized model for predicting the pressure drop in ceramic foams was proposed.