Validation of a lifting surface method for modelling rudder-propeller interaction

The validation of a method for modelling the interaction between a rudder and propeller is the subject of this chapter. A brief description is given of the process of successful validation of a CFD algorithm. The parallel algorithms of the PALISUPAN code are the basis of the lifting surface analysis carried out. Experimental results obtained from the wind tunnel test programme are used to validate firstly a lifting-surface model of a free-stream all-movable rudder (Rudder No. 2), secondly to model the open-water performance of the four-bladed propeller (modified Wageningen B4.40), and finally a representative rudder-propeller geometry. The representative geometry chosen was the mid-longitudinal separation of Rudder No. 2 (X/D=0.39) and propeller, with no lateral separation (Y/D=0.0), and the maximum height of the propeller tip coincident with the rudder tip Z/D=0.75.The development of the interaction velocity field method is described. An aim of the validation exercise was to discover the minimum number of panels necessary to obtain reliable rudder and propeller force characteristics. Also, the minimum number of panels to adequately define the interaction velocity field was found. The minimisation of computational effort allowed the parametric studies, described in the following report, to be carried out within a reasonable time-scale