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International Conference on Innovative Applied Energy    

E-Proceedings ISBN: 978-1-912532-05-6

St Cross College, University of Oxford, United Kingdom



Thermal performance investigation of a smart multilayered wall through CFD simulations coupled to S2S radiation model



Omar IKEN (1)*, Saif Ed-Din FERTAHI (2), Maryam DLIMI(1), Tarik BOUHAL(2), Rachid AGOUNOUN (1), Imad KADIRI(1)

1. Université Moulay Ismail (UMI), Laboratoire d'Etude des Matériaux Avancés et Applications (LEM2A)

2. Université Sidi Mohamed Ben Abdellah (USMBA), École Supérieure de Technologie de Fès


Paper Abstract

In this paper, we present a two dimensional Computational Fluid Dynamic (CFD) simulation of an energy efficient smart wall configuration for thermal building insulation. The simulated multilayered configuration is composed from the outdoor to the indoor respectively of a tungsten (W) doped Vanadium dioxide (VO2) thin film deposited on a glass substrate, an air gap, an Aluminuim nitride (AlN) coating, a cement plaster, brick and cement plaster. Several studies were conducted on smart roofs and walls in the aim of reducing both heating and cooling loads, nevertheless, high heating penalties values still noticed. The objective of this innovative smart wall configuration is to optimize the energy consumption during cold and hot seasons. To investigate the impact of this configuration on energy consumption and indoor comfort, CFD simulations based on a surface to surface (S2S) radiative model were carried out with four different air gap thicknesses (10, 25, 50 and 75mm). Outdoor boundary condition was the solar-air temperature Tsa of south orientation assigned using a user defined function (UDF).

Results have shown that the optimal air gap thickness was 25 mm. This choice was based on Nusselt values and radiative heat flux assessed in the fabry-pérot cavity (glass-air) and (air-AlN coating). Moreover, a comparison between the configuration with optimal air gap and an uninsulated wall composed of cement plaster and brick has shown that the optimal innovative configuration can reduce significantly both heating and cooling loads. In addition, the integration of W doped VO2 as a thermochromic material leads to a regulation of the radiative heat produced by solar radiations on the outdoor surface. In fact, during summer, near infrared (NIR) reflectance of W doped VO2 increase to 70%. While it decreases during winter to around 30%.. 

Paper Keywords
CFD simulations; S2S radiation model; Smart wall; Multilayered configuration; Heating and cooling loads; Thermal optimization.
Corresponding author Biography
Omar Iken is a Ph.D student at Moulay Ismail University, Meknes, Morocco. He received afirst MSc. Degree in Photonics, Micro and Nanotechnologies and Time-Frequency from theUniversity of Franche-Comté (France), and a second MSc. Degree in InstrumentalDevelopment for Micro and Nanotechnologies from the University of Lyon 1 (France). HisPh.D subject is about radiative thermal rectification applied to building thermal insulation. Heis focused on thermo-chromic materials at nanoscale.

The International Conference on Innovative Applied Energy (IAPE’18)