Blockage effects on aerodynamics of isolated tall buildings under uniform turbulent flows

Abstract

Blockage effects on the aerodynamics of rectangular prisms, which represented isolated tall buildings, under uniform turbulent flows were investigated experimentally. Wind tunnel tests were performed on models for four blockage ratios (BR ​= ​4.1%, 6.1%, 8.4%, and 10.1%) under the uniform flows for three turbulence intensities ((IU=0.1%, 4%, and 8%) using the synchronous pressure measurement technique. The blockage effects on the surface pressure coefficient, aerodynamic force coefficient, and Strouhal number (St) were evaluated in detail, and the blockage behaviours of the aerodynamics of models under the different uniform turbulent flows were analysed. The mechanisms of the blockage effects were then revealed. It is found that wind pressures, wind forces, and St increase monotonically with the increase of BR, and the blockage effects are more significant on the fluctuating wind pressures and forces than the time-averaged ones. Additionally, the blockage effects on wind pressures and forces are suppressed with the increase of the inflow turbulence intensity.