STUDY OF INTERFERENCE EFFECT ON FLOW AROUND TALL BUILDINGS

Abstract

The flow of wind in the vicinity of tall buildings develops an adverse condition from the pedestrian point of view and hence influences the safety of pedestrian. The present paper focuses on a comparative study for wind flow around a cluster of two tall buildings. For that numerical simulation of turbulent flow around pair of side by side square cylinder with Reynolds number equal to 21000 is performed using RNG k-c model with two-dimension (2-D) Unsteady Reynolds-Averaged Navier—Stokes equation and the effects of gap ratios (g*= S/D, where S and D are the distance between two square cylinders and diameter respectively) on the flow are being studied. The results of numerical simulation are being compared with experimental results which show different regimes of flow either synchronized or non-synchronized depending upon the gap ratio. When g*< 2 flow is non-synchronized, and for g* > 2 flow becomes in synchronized mode. When g*> 6 flow becomes independent of each other. The average value of drag and lift coefficient (CD and CO for both square cylinders is decreasing with gap ratio. The instantaneous velocity amplification and turbulence intensity at passage center line (Fig. a) is found to be maximum for g* = 1.5 and 1.0 respectively. The vortex shedding frequency characterized by strouhal number (St) is also decreasing with gap ratio, for higher gap ratio its value approaches to the value of square cylinder