Mean velocity and moments of turbulent velocity fluctuations in the wake of a model ship propulsor

Pod drives are modern outboard ship propulsion systems with a motor encapsulated in a watertight pod. The motor’s shaft is connected directly to one or two propellers. The whole unit hangs from the stern of the ship and rotates azimuthally, thus providing thrust and steering without the need of a rudder. Force/momentum and phase-resolved LDA measurements were performed for inline co-rotating and contra-rotating propellers pod drive models (see Fig. 1). Fig. 1 P o d drive model and water tunnel balance The measurements permitted to characterize these ship propulsion systems in terms of their hydrodynamic characteristics. The torque delivered to the propellers and the thrust of the system were measured for different operation conditions of the propellers. These measurements lead to the hydrodynamic optimization of the ship propulsion system