Prediction of effective wake at model and Full Scale using a RANS code with an actuator disk model

This paper describes how the effective wake due to the interaction of hull and propeller is estimated using an actuator disk model. The model takes into account the accelerations induced by the propeller in the flow via body forces. The propeller loading is calculated in an interactive way from the propeller geometry using a lifting line off-design model with a pitch-reduction feature for the tip vortices shed from the blades. The paper shows results obtained from applying the model to a fishing vessel. The influence of the free surface on the effective wake is accounted for. Details of the grid at the location of the actuator disk are illustrated. The computational results include a description of the velocity field at the location of the propulsion unit and wave contours generated by the ship hull and the propulsor. The effect of the working propeller on the development of the stern wave is depicted. Scale effects on the effective wake are shown. The effective wake is illustrated in the form of a spatial wake distribution, and quantified in terms of an average volumetric wake fraction. This investigation was part of the EU project SUPERPROP.