Vertically Perforated Fired Clay Bricks: Thermal Characterization and Numerical Analysis

Abstract

A comprehensive understanding of its thermal properties is essential to use Monomur brick as a thermal insulator effectively. To address this need, the thermal characteristics of Monomur brick samples were evaluated using experimental techniques. The obtained results include values for density, heat capacity, and thermal conductivity of the clay utilized, which are crucial for design decisions. Additionally, a comparative analysis was conducted using various experimental methods, with the measurements compared and revealing error estimates of less than 3% on one hand. On the other hand, the combined heat transfer mechanisms conduction, convection, and radiation across Monomur brick walls were examined utilizing the finite volume method in Computational Fluid Dynamics (CFD) simulations. The governing equations for incompressible flow are the energy equation in conjunction with the Navier-Stokes equations. Given the small temperature differences, the model uses the Boussinesq approximation, assuming the fluid's constant thermophysical properties, evaluated at the average temperature between the outside and interior spaces. Monomur brick surfaces are gray with diffuse reflection, and the top and bottom walls are adiabatic. The results compare the thermal performance of the Monomur brick wall, predicted by a simplified model, with those obtained from the present 3D numerical approach. The discrepancies in design thermal resistance and thermal transmittance between the two methods are analyzed and explained. The assessment of the wall’s thermal performance carried out following UNE-EN ISO 6946 and EN ISO 10211 standards, resulted in a relatively low thermal transmittance coefficient (0.710 W/m²K). This confirms the excellent insulating properties of the Monomur brick under study and its compliance with Moroccan thermal regulations in certain regions.