Numerical analysis of U-shaped groove width effects on vortex-induced vibrations of cylinders

This study employs a fluid-structure interaction (FSI) method with an overlap grid technique to investigate the effects of U-shaped groove width on the vortex-induced vibration (VIV) characteristics of a cylinder. Numerical simulations were conducted on cylinders with three groove widths (W = 0.1D, 0.2D, 0.3D) at two arrangement angles (45° and 90°), analyzing their effects on vibration amplitude, frequency, lift and drag coefficients, and wake vortex shedding patterns. Results show that increasing groove width effectively reduces transverse vibration amplitude compared to a smooth cylinder, with a widening suppression range. At low reduced velocities (U* = 2.0-8.0), lift and drag amplitudes significantly decrease with wider grooves, whereas they slightly increase at high reduced velocities (U* = 9.0-14.0). Distinct from the smooth cylinder, the wake vortex shedding patterns of the U-shaped groove cylinder include not only the SS, 2S, 2T and 2P modes, but also the 2C and P + S modes.