Numerical investigation on hydrodynamic performance of shaftless rim-driven thruster

Abstract

As a new type of propulsion method, the shaftless rim-driven thruster (RDT) has become a research hotspot for ship propulsion due to the absence of the propeller propulsion shaft system setting and the advantages of small cabin occupancy, low noise and low vibration. Numerical investigations were performed to study the effect of blade inclination angle on the hydrodynamic performance of shaftless Rim-driven Thruster. To verify the feasibility of the simulation method, the No.19A + Ka4-70 duct propeller was analysed first and the geometric model of the RDT for the hydrodynamic properties was established in reverse engineering. The hydrodynamic performance of the shaftless rim thruster was studied based on the RANS method, and the performance data of this shaftless rim thruster at each inlet speed coefficient were obtained. Additionally, the characteristics of the change in the inclination angle of the blade relative to its centre axis were examined and the effect of the change in inclination angle on the hydrodynamic performance of the shaftless rim thruster was investigated. Additionally, the numerical calculation results show that a five degree increase in the Z-axis circumferential inclination results in the increase of all the hydrodynamic coefficients of the RDT. Among them, the total thrust is increased by about 14%, the total torque is increased by about 15% and the total efficiency is also comparable to the original thruster efficiency.