Quantification of Gap Effects on Biplane Micro Air Vehicle using Leading-Edge Suction Analogy

This paper investigates the effect of the gap on the aerodynamics of biplane Micro Air Vehicle (MAV) designs. The wind tunnel testing includes recording lift, drag, and pitching moment for four different wing planform shapes; rectangular, Zimmerman, inverse Zimmerman, and elliptical. Five aspect ratios with five different gap positions are tested for each planform shape from 0> to 30>. Subsequently, the leading-edge suction method is used for empirical estimation of vortex and potential induced aerodynamic contributions. Computational fluid dynamics (CFD) modeling is done to visualize flow-field and associated leading and side-edge vortices. The results indicate that as the gap is reduced between two wings for any aspect ratio and planform shape, the lower wing’s leading and side edge vortex is suppressed, thereby jeopardizing vortex-induced contributions.