CFD Investigation of the Three-Dimensional Lift Distribution of a FanWing

The FanWing is a novel propulsion system which utilizes a cross-flow fan to force air over an airfoil to produce sufficient lift at low airspeeds and achieve a higher stall angle than traditional airfoils. In the current literature, only two-dimensional CFD studies have been done for the FanWing, hence the spanwise lift characteristics of the FanWing have been unknown thus far. The following study quantified the lift distribution along a generic FanWing airfoil through a numerical CFD analysis using Star CCM+, a commercial CFD code. Utilizing CFD techniques from previous 2D studies, a 3D CFD analysis was performed, with the resultant spanwise lift distribution being quantified and time averaged. The result was then compared with theoretical values of an elliptical planform under similar conditions utilizing assumptions made from Thin Airfoil Theory and Prandtl’s Lifting Line Theory. The results confirmed the STOL capability of the FanWing propulsion system, given that an equivalent L' for a theoretical elliptical wing necessitated a far higher V∞. In addition, the lift distribution data indicated that the implementation of a FanWing propulsion system onto a rectangular wing planform did not cause the lift distribution data to deviate from the distribution that would be expected from a traditional wing, indicating that the FanWing does not cause a change the lift distribution characteristics of a wing, apart from the magnitude of lift generation. The results given here provide a basis for further computational analysis and experimentation and help increase the understanding of this novel propulsion system.