Effect of three-dimensional stochastic inflow on energy harvesting from flow-induced vibration of three-cylinder oscillator

Flow in realistic ocean environments is inherently stochastic, while most studies on flow-induced vibration (FIV) energy harvesting use idealized uniform inflow. To bridge this gap, this study employs three-dimensional numerical simulations to investigate the FIV and energy harvesting performance of three rigidly coupled cylinders under stochastic inflow conditions. A velocity-dependent noise model was developed to introduce inflow fluctuations with dynamically adjustable intensity, simulating realistic marine turbulence. The results demonstrate that stochastic inflow fundamentally alters the vibration response, inducing non-periodic intermittency between high- and low-amplitude states. Notably, these fluctuations broaden the lock-in range, enabling efficient energy conversion over a wider velocity range. Under large fluctuation conditions, the maximum energy conversion efficiency reached 45.3%, representing a 198% improvement compared to uniform inflow. Furthermore, a strong correlation was established between wake mode and power output, with the 2T mode identified as the optimal flow pattern for energy capture. These insights offer critical guidance for designing three-cylinder energy harvesters for operation in real marine environments.