EXP 1-2

Pollutant transport between a street canyon and a 3D urban array as a function of wind direction and roof height non-uniformity

Front Page

Introduction

Review of experimental studies

Description

Experimental Set Up

Measurement Quantities and Techniques

Data Quality and Accuracy

Measurement Data and Results

Abstract

Understanding the transport and dispersion of pollutants in street canyons, even under neutral atmospheric conditions, is a major challenge. This study presents a dataset obtained from a wind tunnel experiment with two different 3D city models exposed to two wind directions to illustrate the complexity of pollutant transport (both advective and turbulent) between the street canyon and its surroundings. The two city models were designed based on a typical central European city centre with courtyard buildings and pitched roofs. While the first city model had a uniform height, the second model had an uneven height along each street canyon wall. The models were exposed to neutrally stratified atmospheric boundary layer flow in two directions: perpendicular (i.e. 90°) or oblique (i.e. 45°) to the along-axis of the street canyons. The street canyons were polluted by idealised traffic represented by a ground-level line source. Turbulent pollutant (ethane) fluxes were measured at the top and side openings of the street canyons by simultaneously measuring two velocity components and concentration using laser Doppler anemometry (LDA) and a fast response flame ionisation detector (FFID), respectively. The data presented are suitable for validating CFD models focusing on flow and pollutant transport in a 3D urban environment.

Figure 1: The mean 2D velocity vectors measured at each of the street canyon openings. Adapted from [1]

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Contributed by: Štěpán Nosek — Institute of Thermomechanics of the CAS, v. v. i.

Front Page

Introduction

Review of experimental studies

Description

Experimental Set Up

Measurement Quantities and Techniques

Data Quality and Accuracy

Measurement Data and Results

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