A way to increase the efficiency of use of the soft wing area in gliding descent and powered flight systems

Аuthors

Shved Y. V.

e-mail: yuriy-shved@mail.ru

Abstract

The paper considers the ways of increasing the efficiency of lifting area of the soft wings, which are used in the gliding descent and powered flight systems, via engineering solutions. These approaches are based on making the wing rotate about the horizontal axis of the craft and thus create a rotation lifting surface. This way makes it possible to reduce required wing area by more than twice. At that the distinctive features of the «rotoplan» configuration, which is created on the basis of a soft wing, would allow the designer to avoid the known drawbacks of the existing cyclogiro configurations.
The known cyclogyro configurations use multibladed rotors, which are installed on the bearing axes. Large aircraft, which are built according to this configuration, prove to not be efficient. This is caused by excessive weight of rotation axle and blades, which carry a high bending load. Another reason is the additional drag of the structural elements, which support the blades. The ratio of the disc area to the blades area is also worse for a cyclogyro than for a helicopter. However, the use of the soft wing rotation can help to avoid the described cyclogyro disadvantages. In particular:

1. the wing area can bequite large without aserious increase inthe weight;
   
2. the wing itself isinastretched state during the rotation. Atthat itissupported bylines and thus itcan withstand the rotation about the horizontal axis without any additional structural elements;
   
3. norotation axles are required tosupport the soft rotating wing;
   
4. it is possible tochange the shape ofthe wing and its setting angle byusing the available lines without the need for any additional structural elements.

It is possible touse the accumulated kinetic energy ofrotation (angular kinetic energy) for obtaining the additional lift and thus facilitating the landing, which iscarried out with the use ofarotating soft wing. This lift increase can beattained byadditionally increasing the camber ofthe wing profile inthe upper sector ofthe rotation circle. Soft landing requires proportioning the camber increase insuch away that the wing would stop rotating inanear-vertical position atthe altitude, which would beclose tozero for the payload.
The vigorous cyclic variation ofthe setting angle and camber ofthe wing during the rotation can create propulsive force and thus support the wing rotation onits own. Itcan also allot the function ofthe propulsive device tothe soft non-rotating wing.
The soft wing with blowing-type boundary layer control onthe upper surface near the point ofinflection (change ofthe curvature radius) ofthe profile has shown the best lift performance athigh profile camber. Atthat the blowing-type boundary layer control isimplemented bythe appropriately shaped slot inthe abovementioned area ofthe wing [5]. Installation ofvortex generators (inthe form ofstripes sewed onthe shell) inthe area ofinflection can help tomove the beginning (border) ofthe stall region into the area ofhigher camber ofthe wing profile.
Due tothe cyclic action ofthe rotary wing onthe aircraft itisproposed touse such wing for unmanned vehicles. The UAVs, which are built according tothe described principle, can prove effective for carrying out reconnaissance and strike missions due tothe increased maneuverability and low noise ofthe propulsion system.

Keywords:

cyclogyro, rotoplane, gliding descent systems, paraglider

References

1. Fateev E.M. Vetrodvigateli ivetroturbiny (Wind engines and wind turbines), Moscow, Selkhozgiz, 1957, 535p.
2. Sineglazov V.M., Aleshkin S.S., Kulybaka A.V. Electronica tasistemy upravlinnya, 2012, no.3(33), pp. 67- 74.
   
3. The Cyclogyro, Vertiflight, The American Helicopter Society, 2005, vol.51, no.2, pp.16-19.
   
4. Shved Yu.V. Patent RU2456210 С2, 20.07.2012.
   
5. Shved Yu.V. Patent RU2389644 С2, 20.05.2010.
   
6. Shved Yu.V. Patent RU2444462 С2, 10.03.2012.