Aerofoil profile of airborne devices providing higher buoyancy in various flight modes

摘要

In the present invention, there is disclosed a modification of aerofoil profile of airborne devices by transformation of profiles or modification of the existing profile ensuring higher buoyancy, more uniform distribution of buoyancy along the profile depth and delaying separation of boundary layer from the profile in various flight modes. The invention is characterized in that upper side of the profile is modified within a delimited portion so as to have another portion with accelerating pressure gradient in addition to the original portion with acceleration pressure gradient. In this way, a premature separation of boundary layer from the profile at various flight modes is prevented, a uniform distribution of buoyancy past the profile depth is achieved and aerofoil buoyancy is increased. The proposed modification is carried out by a single-stage or multiple-stage transformation i.e. by shift of two or several profiles (13, 14, and 18) relative to each other. Another modification method is modification of the original profile in such a way as to have in front of trailing edge another portion with accelerating pressure gradient within a delimited length of the profile (11) upper side, in addition to that in the leading portion. For laminar profile, the modification is to be carried out in adapted contour of the upper side (19) of the laminar profile front portion. The modified profiles can be used for aircraft aerofoil, helicopter or rotating wing airplane rotor blade aerofoil, wind engine blade aerofoil and for other devices where buoyancy is employed during circumference of surfaces with various media.