Modelling conjugate flow and heat transfer in a ventilated room for indoor thermal comfort assessment

Horikiri, Kana; Yao, Yufeng; Yao, Jun

Abstract

Conjugate natural and forced convection heat transfers in a domestic model room of finite-thickness walls and a heat source have been numerically studied. A 2-D non-ventilated square model room with a heat source is investigated at first for conditions of Prandtl number Pr=0.7 and Grashof number Gr=107. Computational results are compared with already validated numerical predictions and good agreement has been achieved in terms of stream function and temperature distributions. The study continues to consider 3-D ventilated rectangular model room with a finite-thickness wall and a heat source, in order to evaluate flow and heat transfer characteristics. Key physical features such as temperature distributions in both solid wall and indoor air domains, and heat transfer performance have been quantified, analysed and compared. These results provide the correlations among room heating device arrangement, wall thickness effect, indoor thermal comfort level and energy consumption. It was found that the arrangements of heat source and window glazing had significant impact on the temperature field, and further analysis of wall thickness and thermal conductivity variations revealed the level of the comfort temperature within the occupied zone. It was also found that for an average U-value of 0.22W/m2K, thermal energy loss through a thinner wall of 20cm thickness is 53% higher and indoor thermal temperature is 4.6°C lower, compared with those of a thicker wall of 40cm thickness. The findings would be useful for the built environment thermal engineers in design and optimisation of domestic rooms with a heat source. © 2014 Elsevier Ltd.

• Journal Article Type: Article
• Acceptance Date: Mar 27, 2014
• Publication Date: Jan 1, 2014
• Deposit Date: Apr 24, 2014
• Publicly Available Date: Mar 10, 2016
• Journal: Building and Environment
• Print ISSN: 0360-1323
• Publisher: Elsevier
• Peer Reviewed: Peer Reviewed
• Volume: 77
• Pages: 135-147
• DOI: https://doi.org/10.1016/j.buildenv.2014.03.027
• Keywords: Computational fluid dynamics; ; Conjugate heat transfer; ; natural and forced convection, indoor environment, thermal comfort
• Public URL: https://uwe-repository.worktribe.com/output/815275
• Publisher URL: http://dx.doi.org/10.1016/j.buildenv.2014.03.027
• Contract Date: Mar 10, 2016