Abstract:
The main direction of development of modern commercial aviation is not only to improve
the safety and fuel efficiency of aircraft, but also to reduce the impact on the environment,
especially in terms of permissible community noise. One idea is to move the power plant
to the upper surface of the wing to shield engine noise by the wing. Such a solution can
lead to aggravation of the unfavorable aerodynamic interference between airframe elements, forcing the cruising speed to be reduced to the Mach number $\mathrm{M}=0.7$–$0.75$, instead
of the most common $\mathrm{M}=0.78$–$0.8$. Solving the problem of unfavorable interference for
low-noise layouts requires an improvement in the established design methodology.
This paper presents studies on the methodology of designing the aerodynamic layout of a
low-noise aircraft, which has two features: the engines are located above the trailing edge
of the wing, and the wing itself has a small sweep $\chi_{1/4}\sim15^\circ$ with natural laminar flow
(NLF), while maintaining the cruising Mach number $\mathrm{M}=0.78$. An experimental confirmation of the feasibility of this concept has been obtained.