Optimization of cycloidal propeller performance over multiple operating points using a multi-fidelity CFD-Experimental approach

Cycloidal propulsion, also known as the transverse-axis system, holds significant promise for the next generation of ships. Its capability to deliver excellent maneuverability at low speeds, similar to the Voith-Schneider Propeller, and high efficiency at elevated speeds, as seen in systems like ADVPropulse and ABB-Dynafin, makes it a versatile and efficient propulsion solution for a broad range of operational scenarios. Advancements in mechatronics and blade motion control are paving the way for the development of fully electric blade-command cycloidal propellers. This innovation eliminates the constraints imposed by traditional mechanical kinematics, enabling dynamic blade pitch adjustments and significantly broadening the propeller’s operational range and performance. Building on the previously established effective pitch law optimization, the present work employs a multi-fidelity approach to reduce computational costs and better capture the complex physics, which remains challenging to fully optimize using CFD models alone. At the highest level of fidelity, experimental performance evaluations are complemented by CFD simulations, which serve as a lower-fidelity model, balancing computational efficiency and physical accuracy. This multi-fidelity optimization framework is applied across various operating conditions for both cycloidal and trochoidal modes. The resulting series of optimized pitch laws demonstrate the necessity of transitioning from cycloidal mode at low ship speeds to trochoidal mode at high ship speeds to achieve and maintain peak performance.