Investigation of the hydrodynamic performance of a novel small moored tidal-current turbine with Banki rotor

The global energy supply, which heavily depends on fossil fuels, confronts the challenges of resource depletion and environmental pollution, requiring a shift to renewable energy. Tidal-current energy has significant potential but is characterized by intermittency, which restricts its efficiency. To tackle this problem, this study proposes and designs a novel small moored tidal-current energy turbine (SMTET). The SMTET integrates a floating body, Banki rotor, and counterweight to synergistically harness tidal-current and wave energy. Through coupled CFD and mooring dynamics simulations, the system demonstrates: (1) The mooring system induces only deflection (approximately 3°), enabling the turbine to maintain stable underwater operation while preserving hydrodynamic performance; (2) The power coefficient (C_p) peaks at TSR = 0.4, where wave action enhances C_p by 17.5 % (from 0.1680 to 0.1974). This performance improvement confirms the wave-energy enhancement mechanism, primarily achieved through synchronized vortex shedding. These findings provide critical design insights for hybrid tidal-wave energy systems.