Propulsion performance analysis of ring-ribbed ducted propellers

The vortex motion of water caused by the rotation of conventional propellers or ducted propellers cause energy loss in ship propulsion systems. To recycle this part of the energy, a new type of 33+Kd5-100 duct- ed propeller with a triangular cross-section spiral ring rib structure in the rear half of the inner wall of the duct is proposed in this paper. Then, following computational fluid dynamics (CFD) theory, we calculated and evaluat- ed the hydrodynamic performance and energy-saving effect of the ducted propeller using the multizone hybrid grid division method and the moving reference frame (MRF) method. The results revealed that compared with conventional ducted propellers, the thrust and torque coefficients of ring-ribbed ducted propellers can be signifi- cantly improved. When advancing with high propulsion coefficient, the annular fin ducted propeller has varying degrees of improvement in thrust coefficient, torque coefficient, and efficiency. However, its propulsion perfor- mance and efficiency were not as good as those of conventional ducted propellers at low speeds. © 2023 Editorial Board of Journal of Harbin Engineering. All rights reserved.