Unsteady features of bluff body wake with application to building wake length

Abstract

ABSTRACT: This study is targeted at obtaining fluctuating characteristics of building wakes through measurement of unsteady velocity fields with time-resolved particle image velocimetry (PIV). Proper orthogonal decomposition is applied to the PIV data to identify low-dimensional substructures of the building wake. This leads to a more reliable estimation of the fluctuating ground-level length of the building wake from an instantaneous PIV snapshot. The statistics of unsteady wake lengths is important in the probability-based risk assessment of critical events of wind environment around buildings such as dispersion of hazardous pollutants, pedestrian danger and risks to aircraft landings on airport runways.