Investigation of the stability of an unmanned aerial vehicle wing optimizing in terms of its initial shape

A new technology for optimal aerodynamic design of a three-dimensional wing of a middle-class unmanned aerial vehicle (UAV) is considered. An optimal wing shape, which is characterized by minimum drag at a fixed lift coefficient and meeting the specified geometric and aerodynamic constraints, is determined using the heuristic global search method based on the numerical solutions of the full Navier-Stokes equations. The paper shows that the applied optimization method is stable with respect to the initial data (the initial wing shape). An analysis of the obtained aerodynamic characteristics of the optimum wings for a middle-class UAV in two variants of specifying the initial wing shape shows that the proposed technology of optimal aerodynamic design is resistant to the initial shape due to the following aspects: optimal wings are characterized by the same drag coefficient at the main design point; the shapes of optimal wings are very similar to each other; optimal wings have very close (almost identical) integral aerodynamic characteristics in a wide range of flight conditions.