"The underlying concept of using flipperons and other flipperlike actuators to impart desired characteristics to flows is not new. Moreover, elements of flipperon- based active flow-control (AFC) systems for aircraft had been developed previously, but it was not until the development reported here that the elements have been integrated into a complete, controllable prototype AFC system for wind-tunnel testing to enable evaluation of the benefits of AFC for aircraft.
The tests showed that with appropriate actuation of flipperons, lift was increased and drag reduced, by amounts of the order of a percent. Data from these tests were then used to estimate the benefits that could be obtained by adding flipperon-based AFC systems to transport airplanes in two tests cases. In one case, it was found that the addition of the flipperons to the vertical stabilizer of a Boeing 777 (or equivalent) airplane would make it possible to reduce the size of the vertical stabilizer, thereby reducing the drag, by an amount sufficient to enable a reduction of fuel consumption by as much as 1.7 percent. In another case, it was found that by exploiting the ability of a flipperonbased AFC system to delay the onset of stall, one could safely increase the angle of attack (thereby increasing lift) while reducing the size of the wings (thereby reducing the weight) of a blended-wing/ body airplane by an amount sufficient to enable a reduction of fuel consumption by as much as 0.6 percent."
Read More Here : NASA Tech Briefs "Flipperons for Improved Aerodynamic Performance"
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