Simulation-Based Analysis of Hull-Propeller Interaction for a Single-Screw Transport Ship

The hull-propeller interaction of a single-screw transport ship is investigated in model scale using large-eddy sim- ulation. The analysis is focused on the unsteady effective wake and its impact on the propeller. For the configuration under study, there is a significant flow separation upstream of the propeller which influences the operation. A com- plete geometrical model of the propeller is included in the simulations using two different computational techniques (dynamic grids and sliding interfaces respectively). Com- puted quantities include the time-resolved thrust, torque and side forces on the propeller, as well as the load on in- dividual blades. The simulated unsteady flow field in the stern region and around the propeller blades is studied in detail. Results are also provided for the pressure fluctua- tions on the hull above the propeller. Comparison with ex- perimental measurements is carried out both for the flow field and forces on the propeller. Furthermore, results are presented for the towed hull (without propulsion) and the propeller in open-water condition, and the hydrodynamic differences between the conditions are analysed. A dis- cussion is included concerning the important difference between the actual (instantaneous) environment the pro- peller operates in and the averaged flow which typically is used as input in the design process