Vortex Shedding Specifications

 Vibrations

Vortex Shedding Tecnical Specifications

Any fluid flow such as wind passing a structure may cause unsteady flow patterns due to vortex shedding. This may lead to oscillations of slender elements perpendicular to their longitudinal axis.

The aerodynamic phenomenon of Vortex Shedding (vibration problem) has historically occurred in a substantial number of slender structures. This type of dynamic phenomena deserves a meticulous analysis of slender equipment and tall buildings, because it can produce undesirable behavior.

Using the new set of technical specifications, Dynamis has also developed a customized software for REPSOL, in order to detect Vortex Shedding issues in all the existing steel stacks in all REPSOL refineries. For the equipment that didn´t meet the criteria, finite element models representing their geometry, flexibility and mass distribution were created to perform an accurate dynamic analysis.

Finite element models confirmed the accuracy of the criterias developed in the new set of specifications.

Upon conclusion, an analysis considering the American, the Canadian and European standards was conducted, and a final document was generated combining different types of regulations and results obtained in our numerical analyses.

In order to avoid Vortex Shedding in slender steel stacks, REPSOL asked DYNAMIS to draft a new set of technical specifications that take vortex shedding into account using the appropriate criteria.  Engineering solutions have been developed for existing equipment that suffer from the phenomenon (bracing, Tuned Mass dampers, Tuned liquid dampers …).