Joint Effects of Virtual Surfaces on Anti-Icing and Drag Reduction

The operation of the anti-icing system of an airplane can modulate its aerodynamics, whilst an aerodynamic control can alter the icing condition. Therefore, one well-designed control strategy can be expected to yield two benefits, which, however, has not been actively investigated. In this work, the constant leading-edge blowing technique is deployed to achieve joint effects on anti-icing and drag reduction, first on an airfoil and then on a half-airplane model. The results indicate that dual virtual surfaces (an inner one and an outer one) wrapping the leading edge are generated by the blowing control. The inner one prevents water droplets from impacting and accumulating on the airfoil by changing their trajectories. The outer one redirects the shear generated by the blowing and promotes its rolling up and vortex shedding, generating low-pressure zones around the upper leading edge and subsequently reducing drag significantly.