Experiments on Vortex-Excited Oscillations of Axially-Varying Cylindrical Structures in Non-Uniform Approach Flow.

摘要

The long-term goals of this experimental investigation are to identify and understand the important fluid-structure interaction mechanisms that occur during vortex-excited vibrations of axially-varying cylindrical structures in non-uniform flow fields: (1) To study the aerodynamic response of vortex-excited pivoted and cantilevered axially-varying cylinders to uniform and linearly-varying shear flows; (2) To investigate the effects of body geometry and approach flow non-uniformity on the wake parameters such as: vortex formation length, base pressure and Strouhal number; (3) To investigate the near wake flow structure before, during and after lock-in; (4) To investigate the observed hysteresis loops and phase jumps in the lock-in regime; (5) To provide adequate data for van der Pol oscillator modeling of the vortex shedding process for self-excited cylindrical structures in non-uniform flow fields.