Scaled outdoor experimental analysis of ventilation and interunit dispersion with wind and buoyancy effects in street canyons

Yuwei Dai, Cheuk Ming Mak, Jian Hang, Fuyao Zhang, Hong Ling

Research output: Journal article publicationJournal articleAcademic researchpeer-review

Abstract

Driven by wind and buoyancy effects in the urban environment, ventilation performance and pollutant transmission are highly related to human health. In order to investigate characteristics of the single-sided natural ventilation and interunit dispersion problem, this study conducted scaled outdoor experiments in summer and winter periods in two-dimensional street canyons. Tracer gas method was adopted to predict the ventilation rate and simulate the pollutant dispersion. It was found the ventilation performance of windward and leeward rooms showed different trends with wind velocities. Archimedes number Ar was used to examine the interactions of the buoyancy and the wind forces. It revealed that the non-dimensional ventilation rates of all rooms were generally smaller than the results of buoyancy effect only. It indicates that interactions between the buoyancy and wind effects were destructive, which reduced the ventilation rates. The interunit dispersion characteristics with the wind effect were highly dependent on source locations. The results of the tracer gas concentrations of the reentered rooms were not showing simple increasing or decreasing trends. This study provides authentic and instant airflow and pollutant dispersion information in an urban environment. The dataset of this experiment can offer validations for further numerical simulations.

Original languageEnglish
Article number111688
JournalEnergy and Buildings
Volume255
DOIs
Publication statusPublished - 15 Jan 2022

Keywords

  • Buoyancy effect
  • Interunit dispersion
  • Scaled street canyon
  • Urban environment
  • Ventilation

ASJC Scopus subject areas

  • Civil and Structural Engineering
  • Building and Construction
  • Mechanical Engineering
  • Electrical and Electronic Engineering

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