Large eddy simulation of wind-induced interunit dispersion around multistory buildings

Z. T. Ai, Cheuk Ming Mak

Research output: Journal article publicationJournal articleAcademic researchpeer-review

32 Citations (Scopus)

Abstract

Published by John Wiley & Sons Ltd. Previous studies regarding interunit dispersion used Reynolds-averaged Navier-Stokes (RANS) models and thus obtained only mean dispersion routes and re-entry ratios. Given that the envelope flow around a building is highly fluctuating, mean values could be insufficient to describe interunit dispersion. This study investigates the wind-induced interunit dispersion around multistory buildings using the large eddy simulation (LES) method. This is the first time interunit dispersion has been investigated transiently using a LES model. The quality of the selected LES model is seriously assured through both experimental validation and sensitivity analyses. Two aspects are paid special attention: (i) comparison of dispersion routes with those provided by previous RANS simulations and (ii) comparison of timescales with those of natural ventilation and the survival times of pathogens. The LES results reveal larger dispersion scopes than the RANS results. Such larger scopes could be caused by the fluctuating and stochastic nature of envelope flows, which, however, is canceled out by the inherent Reynolds-averaged treatment of RANS models. The timescales of interunit dispersion are comparable with those of natural ventilation. They are much shorter than the survival time of most pathogens under ordinary physical environments, indicating that interunit dispersion is a valid route for disease transmission.
Original languageEnglish
Pages (from-to)259-273
Number of pages15
JournalIndoor Air
Volume26
Issue number2
DOIs
Publication statusPublished - 1 Apr 2016

Keywords

  • Airborne infection
  • Computational fluid dynamics
  • Interunit dispersion
  • Large eddy simulation
  • Multistory buildings
  • Timescales

ASJC Scopus subject areas

  • Environmental Engineering
  • Building and Construction
  • Public Health, Environmental and Occupational Health

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