Propeller design and verification studies for 30–35 meter tugboats

The invention of the propeller, the breakthrough of modern shipping, has supported a much more efficient use of the seas. The propeller consists of helical surfaces placed at equal intervals around a cylinder and can be characterized as ship elements that work like a screw in water. As a result of the rotation of the propeller, the ship to which the propeller is attached makes a translational movement due to the effect-response of the fluid on the propeller. This study includes propeller design and verification as part of a comprehensive project. The scope is the design of a 2m diameter aluminum bronze propeller with 4 blades of 50° backward inclination used on 25–30 m tugboats. Both static and CFD (Computational Fluid Dynamics) analyses were performed and design verification studies were carried out. The forces due to seawater, geometry of the blades, seawater flow rate and blade rotation speed were taken into consideration. The maximum deformation value of 1.7616 mm was obtained at the applied mode 4 value. When all the results obtained were evaluated, there was no need to go back to the propeller design. First of all, the angle value in the propeller geometry was found to be ideal for 50° angle in terms of both strength and fluid mechanics.