  The present work is concerned with the shape optimization of flapping wings
in forward flight. The analysis is performed by combining a gradient-based
optimizer with the unsteady vortex lattice method (UVLM). We describe the UVLM
implementation and provide insights on how to select properly the mesh and
time-step sizes to achieve invariant UVLM simulation results under further mesh
refinement. Our objective is to identify a set of optimized shapes that
maximize the propulsive efficiency, defined as the ratio of the propulsive
power over the aerodynamic power, under lift, thrust, and area constraints.
Several parameters affecting flight performance are investigated and their
impact is described. These include the wing's aspect ratio, camber line, and
curvature of the leading and trailing edges. This study provides guidance for
shape design of engineered flying systems.
