Investigation of the stability of optimal aerodynamic designing of the three-dimensional wing-fuselage layout for a wide-body long-range aircraft with regard to its initial shape

In this paper, the results of investigation of the algorithm stability for optimal threedimensional designing of a wing-fuselage configuration for a wide-body long-range aircraft with regard to its initial shape are presented. The solution to the problem of determining the geometry, which has a minimum value of the total drag coefficient under given geometric and aerodynamic constraints of various types, is obtained using the algorithm based on the combination of the methods of highly accurate numerical solution to the Navier–Stokes equations and the methods of global search optimization with the use of distributed parallel technologies. The multipoint problem of optimal designing consists in the determination of the surface of a multi-sectional spatial wing of aircraft. In the aircraft plan, the wing shape is uniform. The optimal wing satisfies the following condition: the value of a weighted combination of drag coefficients for the wingfuselage layout is minimal at several points of engineering design. The geometric constraints on the wing are independent of the designing conditions and remain unchanged. The aerodynamic constraints on the wing are imposed for each optimization point separately. It was shown that the algorithm is resistant to the choice of the initial shape of the wing, since the optimal geometries obtained for two very different options for initial shape assignment are very close to each other and have almost identical integral aerodynamic characteristics in the cruise flight mode and also in a wide range of this mode.