Abstract:

Present paper investigates the hydrodynamics of a Controllable Pitch Propeller (CPP) which is generated by geometrical modifications applied on a benchmark propeller designed as a fixed pitch propeller (FPP). The aim of the study is to examine the practical feasibility of converting a propeller model designed as a FPP to a new one operating with CPP principles. The flow around propeller models is solved via computational fluid dynamics and the results of the new generated model are presented in comparison with its parent geometry. The well-known KP505 propeller model is chosen as test case. The primary results show that the effect of the geometrical modifications on the propeller efficiency mainly depends on the propeller load and the blade pitch angle. The optimum efficiency point is determined as J=0.8, for the new design model. For the J values below this point, negative pitch angle changes improve the efficiency compared to FPP model. If the J exceeds the above mentioned value, positive pitch angle changes are needed to gain efficiency increase. The results led us to conclude that, it’s possible to convert a FPP to a CPP, but the blade pitch angle should be carefully controlled, for efficient operation

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