The helical strakes are breaking the vortex . This solution could be adopted on cylinder structure if the Scruton number is bigger than 8. In some rare cases they provide the most economical solution.
Only of interest for small stack with small diameters. In all other cases a solution with a damper proves to be more economical.
Placing a damper is an elegant modern solution, which has no disadvantage. This solution is always cheaper than the solution with strakes, except on rare occasions when the stack is small and with a small diameter.
Different types of damper could be used. There is no universal damper :each one has its advantages and disadvantages. On the following pagesyou can see different types of dampers.On bridges, the phenomenon ismore complicated than on cylindrical slender structures and horizontaldampers, vertical dampers and sometimes rotation dampers could berequested.
A vibration damper absorbs the energy due to the vibration and to make the vibration phenomena disappear.
There is no universal damper to solve all vibration problems. Case by case taking into account local conditions (acceleration, amplitude, frequency, space.) will advise you of a given type of damper. dampers are used to suppress horizontal or vertical vibrations. Torsion vibration problems may
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