On the quadrant analysis of the flow in the street canyon

Abstract

It is well known that sweep and ejection are major contributors to the momentum flux in the turbulent boundary layer. In order to evaluate the contribution of these events to the total flux, the wind-tunnel data measured by PIV technique were analyzed from spatial point of view. It was revealed that both the sweep and the ejection reach up to 90% of the flux momentum inside the canyon. Moreover, the sweep and ejection pass the street in an alternative fashion. When sweep reaches maximum, the ejection falls down to minimum and vice versa. The TKE energy is also very high in these particular events, reaching 80-90% of total TKE inside the street what makes the sweep and ejection to be the most important features in the flow.