Numerical simulation of static and dynamic aerodynamics for formation flight with UCAVs
Abstract
Using the effect of wingtip vortex from a leading aircraft, the formation flight of unmanned combat
aerial vehicles (UCAVs) can accomplish various tasks with much more efficiency. Combined with
the sliding mesh technique, this paper investigates a computational fluid dynamics (CFD) method
to simulate and analyze, in detail, the static and dynamic aerodynamic characteristics of formation
with two flying wing models named as SACCON. Besides, the dynamic derivatives indicating the
dynamic stability of aircrafts in formation are identified and validated, and normal single flights are
also analyzed as a comparative study. The results demonstrate that, due to the wake of the leader,
significant enhancements of the wingman are achieved, in terms of the lift-to-drag ratio, pitching,
rolling, and yawing moments in steady states, but the static stabilities are reduced as unbalanced
moments. Moreover, compared with a single aircraft, the unsteady sinusoidal motions indicate
that the dynamic aerodynamics and its corresponding dynamic derivatives change in a much more
complex manner. It is concluded that the initial angle of attack and distance in the formation flight
are the main factors to evaluate the effect, which should be monitored and adjusted in real time for
better use of the profit of formation, especially in dynamic maneuvering.
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