Investigation of lift enhancement through circulation control for distributed propulsion

Abstract

To meet the design requirements for high lift airfoils, an optimization design platform was established using the SNOPT (Sparse Nonlinear Optimizer) method. Two airfoils were designed to achieve both low-speed takeoff/landing and high-speed cruise performance. A comparison between the self-designed airfoils and mature airfoils was carried out at different operating conditions, and the airfoil that met the target requirements was selected. Subsequently, an integrated design of ducted-fan/wing was conducted to study the effect of integrated constraints on the lift augmentation of the wing with the action of the propeller. The results showed that under the integrated layout, the ducted-fan significantly changed the flow velocity field from the front of the inlet and the tail jet, which to some extent changed the upper surface circulation of the wing. Compared with the pure wing, the maximum lift increase was up to 332 %.