Research on the Influence of Key Parameters on the Aerodynamic Characteristics of Shaftless Ducted Rotors

The shaftless ducted rotor (SDR) is a new type of ducted rotor system built using a ducted-rotor-motor integration design. Based on unstructured sliding grid technology, the e ff ects of four key parameters, such as rotor disk height, number of blades, the center hole radius and the blade root mounting angle, on the aerodynamic characteristics of the SDR were investigated. The calculation results show that the thrust performance gradually improves as the rotational speed increases. It is di ff erent from traditional ducted rotors where the rotor is installed near the lip of the duct to obtain the optimal aerodynamic performance, the rotor of the SDR is installed away from the duct entrance to obtain the best aerodynamic performance. Additionally, the number of blades is increased to improve peak thrust and ducted thrust performance; however, this results in decreasing the power load. The central hole radius of the SDR should not be too small, as this can result in an excessive blocking e ff ect when the central air fl ow passes through the paddle. Finally, when the rotational speed is con-stant, increasing the blade root mounting angle results in a large increase in thrust, but this decreases the power load as well.