Motion model of inward-retracting blades of main rotor

V.A.Pavlov, A.L.Bykov

Kazan State Technical University of A.N.Tupolev's name

Bld. 10, K.Marx St., Kazan, 420111, Russia

We study two-dimensionally main rotor  blade retraction inward disc wing in a flying vehicle (FV) combining properties of a plane and a helicopter. To roll the main rotor up kinetic energy of revolution is used. We study the synchronous motion of absolutely identical blades. The aerodynamic drag of the air is taken into account. The Lagrange differential equations of the 2-nd order are used for the closed relationships' derivation. We present the results of the differential equations' numerical integration. The motion of the rotor system has been analyzed as well as the peculiarities of its dynamics have been disclosed.

In the world, for a long time the works have been carried out on creating a flying vehicle combining the benefits of a plane and a helicopter: high flying speed, large load-carrying capacity, and ability to vertically take-off and land. Because of these benefits the flying vehicle can become irreplaceable for use in all cases when fast cargo delivery is needed to a destination having no aerodrome.

The problem can be solved by creation of a changeable flying vehicle with retractable main rotor After vertical take-off and climbing the horizontal speed the blades are retracted inward disc wing which is used to create the lift at this regime. Such solution makes it possible to avoid large aerodynamic losses at high-speed flight characteristic of a vehicle using a lifting rotor.

To retract main rotor blades kinetic energy of revolution is used, thus there is no need in additional engines, reduction gearboxes and transmissions.

The retraction of the main rotor is carried out without turn of the rotation axes, at the expense of kinetic energy of motion, therefore, does not require additional power plants, reduction gearboxes, and transmissions. Such design makes it possible to considerably decrease weight, cost and also increases operational opportunities of the flying vehicle. The present paper is devoured to study of rolling the main rotor up after the landing of FV.