Wind tunnel test of a tailless aircraft with a belly-flap control surface used in combination with wing flaps

A wind tunnel tat of a tailless aircraft configuration that has been quipped with a belly-flap control surface, was conducted with the goal of improving the trimmed maximum-lift coefficient. Tailless aircraft have aerodynamic and structural efficiencies that are superior to those of a traditionally configured wing/body/tail aircraft. However, tailless aircraft have a low maximum-lift coefficient such that; when sized for equivalent takeoff performance, the tailless aircraft suffers a large reduction in aerodynamic and structural efficiencies. A Belly-Flap control surface used in combination with wing trailing edge flaps was tested in a wind tunnel with the goal of achieving a longitudinally trimmed solution at a higher maximum lift coefficient. It was determined that, though the Belly-Flap increases the trimmed lift of the tailless configuration at low angles of attack, the maximum lift coefficient is slightly reduced in relation to the controls neutral configuration.