Computational Fluid Dynamics Analysis of In-Duct Axial/Ducted Fan Aerodynamic Performance

Abstract

In-duct axial and ducted fans are widely used in aircraft environmental control systems, ventilation devices, and unmanned aerial vehicle propulsion units. The aerodynamic performance of such fans is strongly affected by the blade geometry, the duct shape, and the internal flow field. In this paper, a three-dimensional model of an in-duct fan is established, and the internal flow field is simulated by computational fluid dynamics. The blade configuration, velocity magnitude distribution, and flow development inside the duct are analyzed. The simulation results show that the velocity increases significantly near the blade tip and in the wake region behind the rotor. A low-velocity region appears near the hub and the duct wall, which indicates the presence of boundary layer effects and secondary flow. The velocity magnitude at the outlet is higher than that at the inlet, which confirms that the fan provides a positive pressure rise and flow acceleration. A table of key aerodynamic parameters is provided, and several governing equations are used to describe the flow behavior. The results can provide reference for the design and optimization of in-duct fans and ducted fan systems.