PASSIVE CONTROL OF FLOW-INDUCED OSCILLATIONS USING RECTANGULAR NUTATION DAMPERS

This paper studies control of vortex resonance and galloping type of w ind-induced instabilities using rectangular nutation dampers. To begin with, parametric investigation, conducted using a horizontal Scotch-Y oke table, provides favorable configuration of the damper. This is fol lowed by an extensive wind tunnel test program to assess the effective ness of the damper in suppressing wind-induced oscillations. The dampe r also proved successful in arresting vortex resonance of a structure located in the wake of another structure. A flow visualization study o f the surface waves complements the experimental results. It provides better appreciation of the energy dissipation process, which is most e fficient during the condition of wave-breaking.