CFD numerical model for open volumetric receivers with graded porosity dense wire meshes and experimental validation

Abstract

This paper presents a numerical methodology with homogenized equations, together with the main assumptions and boundary conditions to analyze the thermal performance of open volumetric receiver with dense wire meshes and graded porosity. Main numerical results of double and triple porosity absorbers are presented, together with a comparison of the numerical results with experimental data showing a good agreement. The analysis of the results concluded that double porosity absorbers gets the best performance when the rear meshes has a high specific surface area and, triple porosity absorbers are not able to improve on the best case of double porosity absorbers. However, the graded concept has demonstrated to have the potential to improve the performance of single porosity absorbers.