Characterisation of optical properties of solar nanofluids by an inverse problem based on a numerical model

• Published in: E3S Web of Conferences Vol. 321; p. 2020
• Main Authors: Forner-Escrig, Josep, Gimeno-Furió, Alexandra, Palma, Roberto, Hernández, Leonor, Mondragón, Rosa
• Format: Journal Article Conference Proceeding
• Language: English
• Published: Les Ulis EDP Sciences 2021
• Subjects: Cost function; Electromagnetic absorption; Finite element method; Genetic algorithms; Inverse problems; Mathematical models; Nanofluids; Nanoparticles; Numerical models; Numerical prediction; Optical properties; Photothermal conversion; Solar collectors
• ISSN: 2267-1242; 2555-0403; 2267-1242
• DOI: 10.1051/e3sconf/202132102020

Some nanoparticles (NPs) possess an outstanding photothermal conversion under optical illumination. For this reason, these NPs are under research in a wide variety of light-induced heating applications such as solar nanofluids, which could be used for direct light absorption in solar collectors. Experimental characterisation of solar nanofluids for their application to light-to-heat conversion processes requires a considerable amount of resources to determine the properties of this mixture, at the nanoscale level. On this ground, an inverse problem based on a high-frequency and light-to-heat finite element model is proposed in the present work to numerically predict the optical properties of these nanofluids. In particular, a cost function based on a L2 norm is formulated to compare experimental measurements and numerical predictions. Then, this function is minimised by means of heuristic techniques –specifically, genetic algorithms- and the desired properties can be determined. In conclusion, the current work presents a numerical tool that could help in the characterisation of properties of solar nanofluids and contribute to reduce the number of experiments to be conducted for this purpose.