Aerodynamic modeling of ducted fans under environmental disturbances

Abstract

Abstract Ducted fans are widely used in unmanned aerial vehicles (UAVs) to perform various tasks due to high efficiency, high safety and low noise. The external environment affects the stability of the ducted fan, and predicting the aerodynamic characteristics under environmental disturbances is of great significance for stable operations of ducted-fan aircraft. In this paper, we considered the influence of different environmental disturbances on the axial velocity through the rotor disk, and established an aerodynamic mechanism model based on the momentum theory and blade element theory. In order to verify the model validity, three-dimensional CFD (Computational Fluid Dynamics) numerical simulation and bench tests were carried out. The results indicate that the mechanism model can well predict the thrusts and torques of the ducted fan under different flow conditions and wall constraints, and the errors between the model and the simulation results are generally within 12%. Overall, the established model is universal and extendable for different types of disturbances, and has the potential to be applied to evaluate the impact of unknown disturbances.