ANALYSIS OF WIND EFFECTS ON TALL BUILDINGS OF IRREGULAR CROSS-SECTIONS USING NUMERICAL SIMULATION

Abstract

Unavailability of land is an important issue that is to be given due concern, as there is high possibility for this issue to reach an uncontrollable extent due to the increasing population. Authorities are taking possible actions to bring a reduction to these problems, of which construction of high-rise structures is one of the most accepted one. Trends have changed from normal conventional regular structures to irregular shaped high-rise buildings due to land concerns as well as its aesthetic features. But rapid and faster constructions lack proper checking of the structures for dynamic loadings such as wind loads. Unavailability of enough data for irregular structures in codal provisions is also a major limitation, which calls for other effective methods like wind tunnel testing or numerical simulations. Among these alternatives numerical simulations are widely adopted due to its quick and effective nature. This paper deals with wind analysis on two different 'fish'-shaped models for isolated conditions as well as under interference effect. CFD simulation is done in Ansys CFX for different wind incidence angle ranging from 0°-180°. The interval is taken as 15°. The model is of cross-sectional area 400m2 with a height of 60m and is modelled at a scale of 1:100. The variation of Cp at every face of the model at different wind incidence angle, pressure contours for both the models under isolated conditions, horizontal streamlines, comparison of Cp of model under isolated and grouped condition and drag force coefficients of model under isolated conditions are found at the result part. It is found that the face on the windward side experiences more positive pressure when the wind is directly perpendicular to the face of the building. It is also concluded that the interference effect improves the performance of the building.