Wind tunel modeling of contaminant spreadining at an intersection depemding of the approach flow direction
Abstract
The objective of this study is physical modelling of emissions from vehicle exhausts in street canyons within an urban area. The influence of the approach flow direction on contaminant spreading from the vehicle traffic is studied in wind tunnel.
The requirements of the similarity of a real atmospheric boundary layer and a model boundary layer in the wind tunnel are satisfied. For several flow directions mean velocity fields and concentration fields are measured within street canyon intersection inside symmetrical urban built-up area.
Scalar fluxes are computed from measured data to quantify pollutant spreading. Results of the experiment show a significant sensitivity of the mean velocity field at an intersection on the approach flow direction.
The approach flow extensively influence contaminant spreading within the built-up area and therefore intensity of street canyons ventilation vary with the approach flow direction.