Numerical study of relationships between flows and structural characteristics of the rotor in a rim-driven hubless thruster using a strongly-coupling FSI algorithm

The shaftless rim-driven thruster (RDT), as a new type of ship propulsion method, has attracted more and more attention in recent years. In this study, RDT was employed. Firstly, the open water performance of RDT with rigid blade was numerically studied based on the Detached Eddy Simulation (DES). Subsequently, A two-way fluid- structure interaction (FSI) method was adopted to simulate the effects of four flexible blades on the hydrodynamic performance and pulsating pressure. The differences between the hydrodynamic coefficients, flow fields, von Mises stress (VMS), blade deformation, and excitation forces of the flexible and rigid RDT were analyzed. The results show that the blade deformation leads to the loss of thrust and overall efficiency, and the smaller the Young's modulus, the greater the loss of thrust and overall efficiency. As the Young's modulus decreases, the blade deformation in the axial, tangential and radial directions increases, and blade deformation in the axial plays a dominant role in the three directions. Compared with the rigid RDT, blade deformation increases the pulsating pressure of the upstream freestream of blade and weakens the pulsating pressure of the downstream freestream of blade. These findings will provide a reference for the design and optimization of RDT rotor.