VORTEX
SHEDDING ON
TALL
STRUCTURES
Burj Khalifa, Dubai • Source: www.karibuworld.com
M
odern day, tall structures
ity due to the different flow situations
which is referred to as von Karman Vortex
dominate the skyline mak-
arising from the interaction of wind with
Sheet, it can create a significant prob-
ing iconic views, symboliz-
structures. The key phenomenon that the
lem. A Karman Vortex Sheet generally
ing the rapid advancement
engineers have to worry about with flow
forms in the presence of a steady wind
of technology. Early days, North America
of wind is the formation of swirling flows
in a tall structure with a uniform section
was the proud owner of several tall struc-
of air known as the vortices. These vorti-
throughout its height. Thus, a set of tall
tures, but at present Middle East and Asia
ces form on the sides of a structure as the
structures in an area densely packed with
leads the construction of tall structures.
wind blows past it. Such formed vortices
tall structures will not have a significant
This is evident from the fact that the
are shed alternately from one side and
impact from the wind, as the wind will
world’s tallest man-made structure Burj
then the other, giving rise to a fluctuat-
be turbulent with the rapid breaking up
Khalifa, an 829.8m tall building, being
ing suction force acting at right angles to
of vortices. Unfortunately, situation will
owned by Dubai of United Arab emirates.
the wind direction. This phenomenon is
not be the same for a structure stand-
known as the vortex shedding. The vortex
ing apart from others, rising high above
A tall structure has to withstand mainly
shedding is relatively a recent study and
amidst all the surrounding structures. The
two types of loads; gravity lo