Quality and reliability of LES of convective scalar transfer at high Reynolds numbers

Li, Q., Bou-Zeid, E., Anderson, W., Grimmond, S. ORCID: https://orcid.org/0000-0002-3166-9415 and Hultmark, M. (2016) Quality and reliability of LES of convective scalar transfer at high Reynolds numbers. International Journal of Heat and Mass Transfer, 102. pp. 959-970. ISSN 0017-9310 doi: 10.1016/j.ijheatmasstransfer.2016.06.093

Abstract/Summary

Numerical studies were performed to assess the quality and reliability of wall-modeled large eddy simulation (LES) for studying convective heat and mass transfer over bluff bodies at high Reynolds numbers (Re), with a focus on built structures in the atmospheric boundary layer. Detailed comparisons were made with both wind-tunnel experiments and field observations. The LES was shown to correctly capture the spatial patterns of the transfer coefficients around two-dimensional roughness ribs (with a discrepancy of about 20%) and the average Nusselt number (Nu) over a single wall mounted cube (with a discrepancy of about 25%) relative to wind tunnel measurements. However, the discrepancy in Re between the wind tunnel measurements and the real-world applications that the code aims to address influence the comparisons since Nu is a function of Re. Evaluations against field observations are therefore done to overcome this challenge; they reveal that, for applications in urban areas, the wind-tunnel studies result in a much lower range for the exponent m in the classic Nu∼Re m relations, compared to field measurements and LES (0.52–0.74 versus≈ 0.9). The results underline the importance of conducting experimentalor numerical studies for convective scalar transfer problems at a Re commensurate with the flow of interest, and support the use of wall-modeled LES as a technique for this problem that can already capture important aspects of the physics, although further development and testing are needed.

Item Type	Article
URI	https://reading-clone.eprints-hosting.org/id/eprint/66168
Item Type	Article
Refereed	Yes
Divisions	Science > School of Mathematical, Physical and Computational Sciences > Department of Meteorology
Uncontrolled Keywords	Forced convective heat transfer; Large-eddy simulation; Rough walls; Urban heat exchange
Publisher	Elsevier
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