Research on energy recovery of vortex induced vibration in suspension shock absorbers and design of piezoelectric energy harvesters

This study presents a piezoelectric energy harvester (PEH) integrated behind the suspension dampers of smart vehicles, employing vortex-induced vibration (VIV) to harvest wind energy for microsystem power supply. Through systematic investigation of spring-induced windbreak effects, we quantitatively analyzed the correlation between spring compression levels and vortex generation dynamics using suspension travel characteristic tests and confined flow field simulations. Building upon these findings, we developed an equivalent variable cross-section cylinder model to simplify the suspension mechanism. Comprehensive finite element simulations were conducted to elucidate the vortex shedding characteristics and formation mechanisms in the wake of variable-geometry cylindrical structures within bounded flow fields. To enhance energy conversion efficiency, we implemented electrode coverage optimization and impedance matching strategies, effectively reducing piezoelectric losses. These optimizations were systematically validated through multiphysics simulations (COMSOL), bench excitation tests, and hydrodynamic experiments. The PEH’s operational efficacy was further demonstrated through constrained wind tunnel testing and on-road vehicle trials, achieving respective output voltages of 73 and 81 mV under distinct airflow conditions: one featuring lateral wind with turbulence interference, and another under controlled laminar flow conditions.