Advancing Energy Efficiency in Multi-Cylinder Hydrokinetic Converters Through Numerical Modeling

This work explores enhancing energy efficiency in hydrokinetic converters by investigating multi-cylinder configurations with elastic coupling. The model incorporates detailed representations of mass, stiffness, and damping, effectively capturing the dynamics introduced by elastic coupling.The numerical investigation evaluates both connected and disconnected cylinder configurations, uncovering that elastic interconnections yield a more stable and efficient energy extraction process. Notably, the three-cylinder system with elastic couplings reaches a power coefficient ( Cp ) of 0.304, approximately 51.3% of the Betz limit. This result underscores the significant improvement in energy capture when cylinders are elastically connected.Further analysis reveals that the improved performance is due to the more coherent vortex patterns and effective flow sharing among the cylinders, which optimize the dynamic response of the system under varying reduced velocity conditions.The finite volume method and an upwind Total Variation Diminishing scheme (TVD) are used to solve the Unsteady Reynolds Averaged Navier-Stokes equations (URANS), where the Spalart-Allmaras turbulence model simulates the turbulent flow in the wake of the circular cylinders.