VORTEX-INDUCED OSCILLATIONS OF 2 FLEXIBLE CIRCULAR-CYLINDERS COUPLED MECHANICALLY

This paper deals with an experimental investigation of the effect of m echanical coupling on the vortex-induced vibration of a twin-cylinder bundle. The cylinders are in tandem and staggered arrangements and vib rate in-phase and out-of-phase. The separation between the cylinders r anges between 10 and 25 diameters while the stagger angle varies betwe en 0 degrees and 20 degrees for a typical separation of 13 diameters. For each relative position between the cylinders the dynamic response of the in-phase vibration is different from the out-of-phase vibration . The response is greatly dictated by the results of the aerodynamic c oupling investigated previously by the authors. A hysteresis phenomeno n with discontinuities is observed in the response of the bundle and i s explained in the light of the results of previous studies.