梯形截面振子水动力特性数值研究

Flow-induced vibration (FIV) is commonly encountered in engineering applications. Harvesting energy from FIV, as a new renewable energy, has attracted increasing attentions of academics and industries. In this work, direct numerical simulation is employed to investigate the hydrodynamic characteristics of trapezoid-section oscillator. Flow field and hydrodynamic characteristics of oscillators with different ratios of top edge to bottom edge are discussed. The results indicate that the hydrodynamic forces of both triangular- and trapezoidal-section oscillators are larger than the square oscillator. As compared to the square oscillator, the biggest increased percentage on lift coefficient is up to 132.75% occurring in the trapezoidal-section oscillator with d/D of 0.3. When d/D is less than or equal to 0.5, the boundary layers alternately reattach the lateral edges of the oscillator and generate the secondary vortices near the oscillator surface, resulting in the third harmonic frequency. As d/D increases, the vortex formation length grows gradually while the wake width has no distinct change.