Empirically Derived Biplane Lift as a Function of Gap and Stagger
Journal of Aircraft
A number of methods have been proposed to estimate the lift of a biplane based mostly on potential flow methods and arguments. It is noted that positive and negative stagger are treated identically and that lift increases in direct proportion to stagger. Discussion of lift-induced drag is included because of its implied effect on the lift-curve slope.
It will be shown, however, that at least in the flow régime tested for the present work, the omission of the direction of stagger fundamentally limits the application of these results generated in the early third of the 20th century. The present study began with a vortex lattice model study to reduce the experimental test matrix. A generalized method for the prediction of lift coefficient as a function of gap, stagger, aspect ratio, and angle of attack has been determined empirically and subsequently validated.
It is noted that for a couple of the cases, aerodynamically induced vibration prevented acquisition of data within the same band of low uncertainty.
Copyright © 2013, American Institute of Aeronautics and Astronautics
American Institute of Aeronautics and Astronautics
Kang, Hantae; Genco, Nicola; and Altman, Aaron, "Empirically Derived Biplane Lift as a Function of Gap and Stagger" (2013). Mechanical and Aerospace Engineering Faculty Publications. 130.