Numerical investigation on hydrodynamic performance of a novel shaftless rim-driven counter-rotating thruster considering gap fluid

Shaftless rim-driven thruster (RDT) has recently become the research focus for marine propulsion, primarily due to low vibration, noise, and energy saving as its advantage. This study is based on CFD theory used Ansys-Fluent software examine hydrodynamic performance of a novel counter-rotating (RDCRT). It takes No.19A+Ka4-70 duct propeller 20 kW RDT examples, it verifies feasibility simulation method. establishes three geometric models RDCRT's determine whether necessary consider motor stator/rotor gap. examines flow distribution characteristics gap fluid friction force channel investigates gap's influence performance. Relevant case studies indicate that, when considering gap, calculation outcomes model are between stationary rotational rotor inner wall ignoring In Forward Aft regions, total frictional power correspondingly accounts 1.7% 1.35% rated power. Additionally, compared situations with pressure coefficient surface rim without more significant. Thus, should not ignore For RDCRT, thrust coefficient, torque maximum efficiency value significant than those single-propeller RDT, hence validating advantages.