Analysis of the Hydrodynamic Performance of a Propeller by an Annular Free-Rotating Impeller

Hydrodynamic energy-saving devices are widely used in ship energy-saving technologies. To enhance the hydrodynamic performance of propellers, a novel annular free-rotating rotor was designed and installed aft of the KP505 propeller. Computational Fluid Dynamics (CFD) simulations were used to evaluate its performance. Additionally, the hydrodynamic performance of single propellers and propellers with added appendages was compared and predicted under different advance coefficients, and the energy-saving effects were assessed. Results show that the propeller with the added appendage achieves a maximum improvement in propulsion efficiency of 6.59% at the design advance coefficient. This confirms that the annular free-rotating rotor has potential for enhancing propeller hydrodynamic performance.