SIMULATION LAB ®

This research investigates the thrust-enhancement potential of a contra-rotating propeller system, analyzing application 201921018525 and focusing on vortex behavior, interaction mechanisms, and downstream flow restructuring. Contra-rotation introduces two key aerodynamic phenomena: the advancement of traditional vortex theory and the formation of an early-stage vortex cover, which our study confirms can increase downstream velocity up to four times compared to conventional single-propeller vortices. Detailed flow analysis reveals that shifting the interaction zone between the primary and secondary vortices causes a substantial relocation of the maximum thrust region, with the primary vortex remaining strong near the main blade and bending downstream due to destabilization or decapitation triggered by the opposite-spinning secondary vortex. Mid-stream observations show the secondary vortex contributing simultaneously to vortex-cover formation and rotational energy transfer, with this dual effect persisting across energy levels. The convergence effects indicate that although the secondary vortex interacts with the primary vortex from its formation, the primary vortex’s core pull remains largely intact. Initial findings further show that turbulence intensity critically influences ducted tidal turbines with convergence angles below 10°, and that propeller rpm exhibits a complex relationship with thrust and torque, requiring deeper multivariable coupling analysis. Overall, the study advances understanding of vortex-driven thrust enhancement and establishes foundational insights for optimizing contra-rotating propeller systems in hydro power applications.