Description:
Alternate shedding of vortices from long
slender structures may cause vortex induced vibration leading to fatigue type
failure of the body by imposing periodic pressure changes on its surface. The
invention of attenuation of regular formation of vortex shedding is
achieved. The presence of a bi-stable instability has been discovered for
cylinders with a surface modification. At this particular unstable
configuration,
*Flow lies between two different stable
states
*Regular Karman vortex shedding
stops
*Shear layer flapping arises at a broadband
low frequency.
This technology involves the use of a
surface modification to a cylinder to attenuate vortex induced vibration caused
by flows at a certain angle of attach and velocity.
Advantages
In this system, according to the flow
situation, the perturbation can be brought to the critical position that stops
Karman vortex shedding. Flows of varying angle of attach and velocity may
use this technology by modifying the method via using an automated system.
Applications
*Heat exchanger tubes
*Slender structures on petrol drilling
platforms
*Bridge piers
*Chimney stacks
*Other slender structures
Status
and Intellectual Property
A U.S.
provisional patent application has been filed.