Sajad Hajizade

The importance of the use of marine propellers on ships and the complexity of the design has left many ambiguities and unanswered questions, despite many studies in this field. The present work was the parametric analysis of a propeller using Ansys CFX software. Investigation and research in this area in order to improve performance can make a significant contribution to optimizing the fuel efficiency of ships and the useful life of the impeller due to the cavitation phenomenon. The three important parameters of rake angle, expanded area ratio and step ratio have been studied to achieve the maximum propulsive force and the minimum number of cavitation. The results show that by increasing the rake angle to the blade stall angle, the propulsive force generally increases; but the cavitation number is also increasing, which is not desirable. The high ratio of the developed area leads to the passage of current at the edge of the blades to have fewer bubbles, which reduces the number of cavities. With increasing area ratio, it is observed that the propulsive force takes an upward slope and reaches a maximum in the amount of 0.61. Examination of the values of the cavitation number in terms of pitch ratio shows that the amount of cavitation in the minimum state of the propulsion force in the range of 0.9 has also reached the target state of optimization and minimum cavitation. Finally, the optimal geometry has a 14% increase in propulsive force and also has a lower cavitation number at the design point.