Investigation of Thermal Behavior of Different Common Roofing Systems in Buildinings Using Computational Fluid Dynamic Method

Document Type : Original Article

Authors

1 Department of Mechanical Engineering, Vali-e-Asr Univeristy, Rafsanjan, Iran

2 Department of Civil Engineering, Vali-e-Asr Univeristy, Rafsanjan, Iran

Abstract

In this study, the influence of type and structure of different roofing systems were investigated using a computational fluid dynamic method. The considered roofing systems include beam and block types (clay bricks, light weight concrete blocks, polystyrene) and Uboot slab designed for 6m and 8m span. To simulate the fluid flow and the heat transfer, the computational fluid dynamic method was employed based on a control volume scheme. Heat transfers inside air cavities are carried out via free convection and radiation, while heat transfers within solid walls via conduction. The thermal simulation of roofing systems was analyzed both for summer (downward heat flow) and for winter (upward heat flow). Two-dimensional natural heat transfers were considered to be transient with laminar and the incompressible flow inside cavities. To assess the thermal performance of flooring systems, equivalent thermal conductivity, decrement factors, and time lag were studied. Finally, the best roofing system was introduced in terms of heat transfer and thermal mass efficiency. The results showed that roofs with polystyrene block have the lowest value of equivalent thermal conductivity, while Uboot systems have the highest heat loss among the studied cases.

Keywords

References

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Energy Engineering and Management
Volume 13, Issue 1
March 2023
Pages 122-135

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