Optimal aerodynamic design of a wing-body configuration for a wide-body long-range aircraft

This paper presents the results of a multi-point optimal aerodynamic design of a “wing-body” configuration for a wide-body long-range aircraft. The solution to the problem is obtained on the basis of a combination of numerical solution to full Navier-Stokes equations for turbulent flows of viscous compressible gas and method of global optimal search based on the Genetic Algorithms with account for design parameters and constraints. The applied method implies the calculation of the drag coefficient, which is required for optimal search, on the basis of the approximation of the local database established using the calculated flow around the tested geometry in its discrete vicinity in the given search area. To ensure the accuracy of the calculated results, the irregular grid refining is used in the vicinity of the aircraft surface. The considered designing takes into account two points corresponding to the transonic flight speeds and one point corresponding to the subsonic flow around in the take-off mode.
The optimal geometry is characterized by low full drag in cruising conditions. The designing made it possible to shift the point of the shock stall initiation towards the large Mach numbers by at least 0.02. The aerodynamic characteristics of the optimal “wing-body” configuration are significantly better than those of the aircraft of initial shape in a wide range of the Mach number and lift coefficient. The optimal “wing-body” geometry meets all the given design parameters and design constraints.