Optimization of Roof angle for Sloping Roof Buildings under Extreme Wind Conditions

Abstract

A downburst that occurs during a thunderstorm is a strong downward current of wind which comes down with high speed from the cloud level and hits the ground. After hitting the ground it spreads radially outward in all directions. These are generally destructive in nature. There are evidences of downburst causing extensive damages to buildings, electrical installations etc. In India thunderstorms often occur during pre-monsoon and post-monsoon seasons particularly in north-eastern and eastern part of the country. Sloping roof building structures are quite common in this part of the country. In this paper, an attempt has been made to numerically simulate the pressure distribution over a sloping roof building subjected to downburst wind so as to predict the building load. Predicted pressure distributions under downburst has been compared with those under the influence of normal synoptic boundary layer type horizontal wind profile. Flow over a 3D model of sloping roof building has been generated using ANSYS CFX to predict the pressure distributions on the building surfaces including the roof at various slope angles and thus predict the optimum slope which gives the minimum lift force on the roof.