Energetically Optimal Short-Range Gliding Trajectories for Gliding Animals

Maximum range in steady-state glides is achieved when the lift coefficient is chosen to maximize the lift-to-drag ratio. Whether or not this same steady-state result applies to animal gliders is examined. Because animal gliders spend relatively little time in the air and glide relatively short distances, it is expected that the transient behavior at the beginning and end of the glide will govern their performance. A time-dependent, two-dimensional computational dynamics model is used to predict glide trajectories for biologically inspired gliders. The results demonstrate that glide range is greatest when the lift coefficient does not correspond to that predicted by classical steady-state gliding theory. This indicates that the transient dynamics of short-range gliders are important in maximizing their range.