Numerical evaluation of the extinction coefficient of honeycomb solar receivers

Rami Elnoumeir, Raffaele Capuano, Thomas Fend


Open volumetric receivers are porous media used in absorbing concentrated solar radiation reflected from a heliostat field with the objective to gain heat for an electricity generating thermal engine. Air is sucked through the hot, open porous material and heats up to high temperatures before it enters the steam generator of a turbine. In order to optimize these components in terms of pore geometry, a numerical prediction of the heat transfer and flow properties is useful. Due to the high complexity of the porous media’s microstructure, effective parameters are used to describe the physical phenomena occurring in such structures on a macro-scale level. This study evaluates numerically one of the necessary parameters: the effective extinction coefficient. It describes how the concentrated radiation is absorbed in the volume of the receiver. For this purpose, a self-developed numerical tool in ANSYS environment has been used. The developed tool calculates the effective extinction coefficient of the solar radiation striking the receiver’s inlet at any angle of incidence. Afterwards the tool can be applied for various honeycomb geometries and the generated coefficients may be used to predict the complete thermal behaviour of the receiver with the purpose to find a new geometry with a higher solar-to-thermal efficiency.

Total Views: 330


Solar tower technology, volumetric receiver, effective properties, extinction coefficient

Full Text:



T. Fend, “High Porosity Materials as Volumetric Receivers for Solar Energetics”, Optica Applicata. 40 pp.

-284, 2010.


R. Capuano, T. Fend, P. Schwarzbözl, O. Smirnova, H. Stadler, B. Hoffschmidt, “Numerical models of advanced ceramic absorbers for volumetric solar receivers”, Renewable and Sustainable Energy Reviews 58 pp. 656–665, 2016.


R. Capuano, T. Fend, B. Hoffschmidt, R. Pitz-Paal, “Innovative Volumetric Solar Receiver Micro-Design Based on Numerical Predictions” ASME 2015 International Mechanical Engineering Congress and Exposition, Volume 8B: Heat Transfer and Thermal Engineering, Houston, Texas, USA, November 13–19, 2015.


B. Hoffschmidt, Téllez Félix M., A. Valverde, J. Fernández, V. Fernández, “Performance Evaluation of the 200-kW[th] HiTRec-II Open Volumetric Air Receiver”, J. Sol. Energy Eng. 125 pp 87-94, 2003


T. Fend, B. Hoffschmidt, R. Pitz-Paal, O. Reutter, P. Rietbrock, “Porous materials as open volumetric solar receivers: Experimental determination of thermophysical and heat transfer properties”, Energy, 29, pp. 823–833, 2004.


V. Jambhekar, “Forchheimer porous-media flow models-numerical investigation and comparison with experimental data”, Master Thesis, University of Stuttgart; 2011.


J. Mils, “A continuum approach to two-phase porous media”, Transport in porous media. 35, pp. 15-36, 1999


T. Fend, R. Pitz-Paal, B. Hoffschmidt, O. Reutter, “Solar radiation conversion”, in: “Cellular Ceramics: Structure, Manufacturing, Properties and Applications” (eds. M. Scheffler and P. Colombo), Wiley-VCH, Weinheim, 2005


T. Fend, P. Schwarzbözl, O. Smirnova, D. Schöllgen, C. Jakob, “Numerical investigation of flow and heat transfer in a volumetric solar receiver”, Renewable Energy. 60, pp. 655–661, 2013.


S. Mey, C. Caliot, G. Flamant, A. Kribus, Y. Gray, “Optimization of High Temperature SiC Volumetric Solar Absorber”, Energy Procedia, 49 pp. 478–487, 2014.


R. Siegel, J. Howell, M. Menguc, Thermal radiation heat transfer, 5th ed, Taylor & Francis, 2010.


Reference Manual, FLUENT 6.3, Discrete Ordinates (DO) Radiation Model Theory.


O. Smirnova, T. Fend, S. Peter, D. Schöllgen, “Homogeneous and Inhomogeneous Model for Flow and Heat Transfer in Porous Materials as High Temperature Solar Air Receivers”, European. COMSOL Conference, Paris, 17-19 November 2010


G. Koll, P. Schwarzbözl, K. Hennecke, T. Hartz, M. Schmitz, B. Hffschmidt, “The solar tower Jülich—A research and demonstration plant for central Receiver Systems”, SolarPACES Conference, Berlin, 15. - 18. September 2009


  • There are currently no refbacks.

Online ISSN: 1309-0127;;

IJRER is cited in SCOPUS, EBSCO, WEB of SCIENCE (Thomson Reuters)