Aerodynamic Characteristics of a Ducted Fan System Based on Momentum Source Method

Abstract

Ducted fan systems have received a considerable attention due to their potential for wide application in both civil and military missions. Compared with isolated fans, the presence of duct can substantially weaken the contraction of fan wake and gives the potential to fly efficiently with high security, compact structure and low noise. Based on the momentum source method (MSM) and the S-A turbulence model, a computational fluid dynamics (CFD) simulation model is established and validated as a reliable tool by comparing with calculation results based on sliding mesh technique. The effect of the revolution speed, flight velocity and angle of attack on the aerodynamic characteristics of the ducted fan system is evaluated in detail. The calculation results show that the thrust of the ducted fan system shows an approximate quadratic increase with the increasing revolution speed; As the vertical velocity increases, the thrust of the ducted fan system increases first and then decreases; As the forward velocity increases, the lift and drag of the ducted fan system increase; As the angle of attack increases, the drag of the ducted fan system increases and the lift first increases and then decreases.