Japan Aerospace Exploration Agency

Yoshine Ueda

Hiroaki Ishikawa

Naoko Tokugawa

Kenji Yoshida

Taro Kawai

Ayako Tozuka

Kisa Matsushima

[Object] To provide a wing achieving reduction of friction drag and easy to design and also easy to manufacture and an aircraft including such a wing. [Solving Means] A wingis typically used as a main wing of an aircraft. The wingis a swept-back wing having a swept-back angle A. The wingis configured such that a surface pressure (pressure distribution (Cp)) on an upper surface of a vicinity of a leading edgein a fluid increases from a wing rootto a wing tip. A cross-flow component of an external streamline of a surface of the wingis reduced in the vicinity of the leading edge, and boundary layer transition is not easily induced in the vicinity of the leading edge. With this, friction drag caused by cross-flow instability can be reduced.

Wing and aircraft

Provided is a nose for a supersonic flying object, which has a natural laminar flow nose shape capable of suppressing laminar-turbulent transition and drastically reducing a frictional drag. The nose for a supersonic flying object has a low resistive body shape symmetrical about a central axis as a base shape, wherein the base shape is approximately a cone shape having a linear, simple convex curve, or simple concave curve generatrix and a deformation element having a wavy shape is added to the base shape.

Nose for supersonic flying object

In designing supersonic aircrafts, a method of designing a natural laminar flow wing is provided which reduces friction drag by delaying boundary layer transition under flight conditions of actual aircrafts. A target Cp distribution on wing upper surface, suited to natural laminarization in which boundary layer transition is delayed rearward in desired Reynolds number states, is defined by a functional type having as coefficients parameters depending on each spanwise station, a sensitivity analysis employing a transition analysis method is applied to the parameters, and a search is performed for the optimum combination of parameters to delay transition rearward.

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Tokyo, Japan

Yoshine Ueda