Numerical Study of the Efficiency of Single-Row Ducted Propellers with Equal Solidity and a Different Number of Blades

This paper compares efficiency of various approaches to changing the design shape of propellers to meet strict requirements for the overall dimensions of the propulsion unit on an aircraft. Propeller solidity ratio is considered and a method for increasing its value to reduce the dimensions of the propulsion unit without significant loss of aerodynamic properties, is proposed. According to the results of the study, it was found that, in terms of aerodynamics and specific thrust per unit of power, the most effective way to increase a propeller solidity ratio is through an increase in the chord value of the blade. The nature of the change in aerodynamic properties when changing the propeller solidity ratio also significantly depends on the shape of the blade profile.