Analysis Of The Wings And Powerplant Changes At The Time Of Civil Aircraft Variant Development

Abstract

For the transport category aircraft variants creation there are some ways. They are: keeping constant area and other geometric parameters of a wing and solve this task by the serious modification of a powerplant; modifying area and geometric parameters of a wing for an existing powerplant. Both of these ways have their own advantages, but in time for their realization there are some problems: excessive growth of new variant airplanes’ takeoff weight; possible derating of the takeoff and landing performance for a new airplane’s variant; derating of the fuel efficiency and other integral airplane’s performances that are reasons for the decreasing of the new variant’s competitive. The best performance of the new variant airplane can be obtained only at one condition: these changes are created synchronously and consistently. In the article the way of such changes coordination for increasing cargo capacity, flight range and fuel efficiency of new aircraft variant was created. The main specific of the proposed way is modification changes of a wing geometric parameters are providing of the decreasing its inductive drag for given lift. The model of design changes influence of wing geometric parameters such as taper ratio and local chords twist angle that are depending on elliptical factor of taper wing, to wings polar graph and its lift-to-drag ratio are proposed. Step-by-step evaluation for aerodynamic quality dependence on required values of lift coefficient CL and specific lift coefficient $\overline{C}_{L}$ are given. CL and $\overline{C}_{L}$ depend on coordination of modification changes for a wing and powerplant performance. The scope of lift-to-drag ratio $K(C_{L})$ for possible applying of required cargo capacity increasing was determined. Obtained results that relate to simulation of geometric wing changes are inherent part of the deep modification changes coordination for a wing and powerplant, which are needed for new aircraft variant creation with higher productivity.