Ka4-55 Series Based Toroidal Propeller Design

Toroidal marine propellers have become a phenomenon in the propeller design world, as their design can enhance propeller performance exceeding conventional designs. Toroidal propeller blades typically feature a small Ae/A0 ratio and, relatively constant chord. One of Kaplan's propeller series, Ka4-55, has the required features and provides comprehensive open water test data. This study investigates the possibility of Ka4-55 being used as the base of a toroidal propeller and evaluates the performance using the CFD method. To conduct a more detailed analysis of which part contributes significantly to the performance, the blade area is divided into three sections: S1, close to the root area; S2, in the middle; and tip. The analysis indicates that toroidal propellers based on Ka4-55 provide high thrust for low to medium advance coefficient (J) and higher efficiency for higher advance coefficient (J) with a range of J > 0.8.