A comprehensive numerical study on flow-induced vibrations with various groove structures: Suppression or enhancing energy scavenging

This paper focuses on the enhancement or suppression effect of flow-induced vibration (FIV) caused by sym-metrically installed groove structures with different shapes under high Reynolds numbers. The fluid flow field is simulated using the non-constant two-dimensional Reynolds-averaged Navier-Stokes (2D-RANS) equation and the SST k-omega turbulence model. A cylinder attached to four different groove shapes (square, triangular, semi-circular, and two quarter-circle splices) is simulated for each shape of the groove with five mounting angles. The oscillatory amplitude, frequency response, displacement time history curve, vortex shedding mode, and energy harvesting characteristics are analyzed for each working condition at 2 < U* < 14 and 2.02 x 104 < Re < 1.44 x 105. The results show that the cylinder with different groove shapes and installation angles have different dy-namic responses. The oscillatory amplitude of the square groove bluff body with alpha = 30 degrees, 60 degrees, and 150 degrees is basically enhanced compared to the smooth cylinder, and the working bandwidth is increased as well. For the square groove placed at alpha = 60 degrees, the oscillatory amplitude increases by 100% compared to the smooth cylinder, and the working bandwidth of the square groove at alpha = 90 degrees is reduced by 50%. For the square groove body with alpha = 120 degrees, the amplitude is enhanced, but the working bandwidth is reduced. The working bandwidth of the triangular groove is widened at all five angles, with the alpha = 60 degrees groove being optimal, widening by 75%. Except for the triangular groove with alpha = 90 degrees, the amplitude is improved to some extent compared with the smooth cylinder. The working bandwidths of the semicircular grooves are widened, and the improvement effect of alpha = 150 degrees is the smallest of the five angles. For the two quarter-circle splices grooves, the grooves arranged at alpha = 30 degrees, 90 degrees, 120 degrees, and 150 degrees have a decrease in amplitude when U* = 6, and more pronounced at 90 degrees and 120 degrees. Two quarter-circle spliced groove cylinders with alpha = 120 degrees have the best amplitude enhancement effect.