Numerical Analysis of the Hydrodynamic Performance Impact of Novel Appendage on Rim-driven Thruster

Addressing the ongoing challenge of enhancing propulsion efficiency in rim-driven thrusters (RDTs), a novel energy-saving appendage was designed to mitigate energy dissipation and improve efficiency. Computational fluid dynamics was utilized to examine the disparities in open-water performance between RDTs with and without this appendage. The Reynolds-Averaged Navier–Stokes equations were solved using the Moving Reference Frame approach within the established STAR-CCM+ software. The accuracy of these methodologies was confirmed through a comparison of numerical simulations with experimental data. A meticulous analysis evaluated the alterations in propulsion efficiency of RDTs pre- and post-appendage integration across various advance coefficients. Additionally, a comprehensive assessment of thrust and torque coefficient distributions facilitated a comprehensive understanding of the appendage’s energy-saving potential. Results demonstrated that the new appendage diminishes the diffusive wake behind the rotor disk, fostering a more uniform flow distribution. A notable reduction in the low-pressure zone on the rotor blade’s thrust side was observed, accompanied by an elevation in the high-pressure area. This generated a distinct pressure disparity between the blade’s thrust and suction sides, mitigating the low-pressure region at the blade tip and reducing the likelihood of cavitation. The manuscript further elucidates the rationale behind these alterations, providing detailed insights into flow field dynamics.