EFFECT OF CAVITATION EROSION OVER A NI-AL-BRONZE PROPELLER

Commercial vessels with large deadweight capacity engaged in international voyages are generally powered by a single propeller. Hence, because the responsibility for developing the thrust force lays upon a single thrust component and redundancy cannot be ensured, a comprehensive evaluation for the operational conditions is to be carried out, as the propeller is closely related with the hydrodynamic seaworthiness of the vessel, which should precede any propulsion analysis, [1-2]. Despite the proven reliability of the nickel–aluminium-bronze alloy (NAB hereafter) used in its manufacturing, a marine propellers exposed to the risk of extended cavitation, the propeller is prone to localised wear and surface degradation. This is the reason of the present research aimed at is addressing the problematics of cavitation erosion of NAB propellers by employment of CFD investigation instruments. Cavitation occurrence is emphasised on a simplified three blades propeller together with hydrodynamic characteristics evaluation. Hence, the initiation of the cavitation on the blades surfaces is described together with a brief introduction of the most commonly used mitigation and recondition techniques of cavitation affected areas of propeller blades through modern methodologies.