Wind is a random phenomenon because of the many flow situations arising from the interaction of wind with structures. The turbulence of strong winds in the lower levels of the atmosphere arises from interaction with surface features. An outcome of the turbulence is that dynamic loading on a structure depends on the size of eddies. Large eddies, comparable with the structure introduces correlated pressure as they envelope with the structure.
There is rapid increase in the number of lattice towers being mounted on roof-tops of building for communication purpose. The wind turbines are also being installed to reduce power consumption of building to achieve green building status.
CFD technique is more economical and widely available compared to wind tunnel facilities. In recent years, working industries such as aerospace and motor industries using this computational tool have been largely developed to predict the flow of air around aircraft. It involves mostly attached flow over streamlined bodies with relatively small areas of separation and turbulent length scales smaller than the body under investigation.
Characteristics of wind:
Wind is air in motion relative to the surface of the earth.
The wind generally blows horizontal to the ground at high wind speeds.
The wind speeds are assessed with the help of anemometer.
Very strong winds (greater than 80km/h ) are generally associated with cyclonic storms, thunder storms, dust storms, and vigorous monsoon.
The magnitude of fluctuating component of the wind speed which is called ‘gust’, depends on the averaging time.
The wind loads and wind speed considerations are calculated with the help of IS: 875 (part-3). The basic wind speed, design wind speed, risk coefficient factor, terrain, height, and structure size factor, topography factor, and design wind pressure can be calculated from code book.
For the analysis of wind loads, displacements, shear forces, and moment diagrams. we can make use of concept computational fluid dynamics with the help of FLUENT software.
Numerical simulation and analysis of loads and design considerations can be done with the help of FLUENT software. This will help in reducing the failures and sudden collapse of the lattice towers and also wind turbines.
Kit required to develop Numerical simulation of wind flow: