Roll Control for Aircraft, Particularly Flying Barrels, Adapted to Be Driven by Means of Ducted Fans

The present invention relates to a roll control for aircraft, particularly flying barrels, adapted to be driven by means of ducted fans, which comprise at the end of the flow channel a pivotal reversing or deflecting louver for vertical flight, hovering flight, transition, and high-speed flight.

An aircraft is known under the name of "Aerodyne" (Dornier Post 1-1973, page 17 et sequitur) in which a flow channel is present within a fan shroud, at the end of which the jet may be reversed or deflected downwardly by a series of flaps. The exhaust gas jet of the propulsion unit is guided rearwardly at the inside of the tail boom and there serves for the yaw and pitch control in hovering flight. During high-speed flight, the pitch and yaw controls are effected by the control surfaces of a conventional tail unit at the end of the tail boom. The roll control is effected in hovering flight and in forward flight by means of a vertical keel flap which is mounted immediately behind the main cascade flaps and which, by virtue of its mounting under the center of gravity, furnishes a rolling moment during the deflection.

It is the object of the present invention to provide for an effective roll control for aircraft, particularly flying barrels, with ducted fans, which requires only a moderate number of mechanically movable parts, and which is readily responsive.

This object is obtained, in accordance with the present invention, in the case of aircraft provided with a ducted fan by virtue of the fact that the flow channel is subdivided into two flow channels by a vertical separating surface, and that mounted at the leading edge of the separating surface is at least one vertical flap which is pivotal about a vertical axis. By means of flaps behind the impeller, the flow may be unilaterally so deflected that one part of the reversing louver produces a greater thrust than the other, which leads to the generation of a rolling moment.

According to another advantageous embodiment of the present invention, the space between the impeller and the reversing louver is subdivided, by a cell enclosing the drive aggregate, into two channels extending substantially vertically, and vertical flaps guide the flow coming from the impeller into one channel or the other. Thereby also rolling movements may be sensitively initiated or compensated for.

Further advantages, features, and possibilities of application of the present invention will become apparent from the accompanying drawings, the figures of which are described hereinbelow and wherein

FIG. 1 is an illustration, in principle, of an inventive aircraft during high-speed flight;

FIG. 2 illustrates a flying barrel according to FIG. 1 in vertical flight;

FIG. 3 is a side view, partially in cross-section, of an inventive aircraft according to FIGS. 1 and 2, and

FIG. 4 is a view, in horizontal cross-section, according to FIG. 3.

FIG. 1 shows an aircraft 2 of the flying barrel type during high-speed flight. The aircraft 2 is composed of a useful load tip 4, a propulsion unit (not visible in FIGS. 1 and 2), a shroud 6, a tail boom 8, and a tail unit 10. During high-speed flight, the flow 12 is only slightly deflected in a direction opposite to the force of gravity, whereas during vertical flight and the transitional phase, the deflection is considerably greater, as shown in FIG. 2.

The cross-sectional view of FIG. 3 illustrates the interior of the shroud 6. The flow 12 is generated by means of an impeller 14 which is provided with adjustable blades. The shaft turbine required for the drive of the impeller 14 is mounted within a cell 16 which is shown in a top plan view in FIG. 4. The cell 16 subdivides the inner flow channel 18 into two flow channels 20 and 22. The divided flow 12 is deflected by two separate deflecting louvers or cascades 24 and 26 in a direction opposite to the force of gravity. The cell 16 is so constructed that it extends in a wedge-shaped manner forwardly up into the vicinity of the impeller 14. It divides the flow channel 18 in a vertical plane. The two flow channels 20 and 22 have similar cross-sectional surfaces and guide the flow toward the two deflecting louvers 24 and 26 without contour jumps, which louvers either may be positioned parallel with respect to each other, or form a V with each other.

It is thus possible, by means of influencing the cross-sectional surfaces of the flow channels 20 and 22, to so control the mass flow of the flow 12 that a thrust difference is produced between the two louvers 24 and 26, and therewith a rolling moment.

For this purpose, the front part of the cell 16 above and below a hub 28 is constructed as the flaps 30. The two flaps 30 are deflected simultaneously toward the same side for effecting roll control, whereby the mass flow in one flow channel, 20 or 22, is increased and diminished in the other. The extent of the deflecting angle of the flaps 30 is dependent upon the required rolling moment. Shown in full lines in FIG. 4 is a flap 30 in the neutral position thereof, and in phantom 30' when producing a rolling moment.

The roll control by means of a differentiated subdivision of the mass flow 12 to the louvers 24 and 26, by means of the flaps 30 arranged behind the impeller 14 is characterized by simplicity, low structural weight, and a high degree of effectiveness. Also utilized are the advantages of a central structural group of the cell 16 as a compact drive unit which contains the propulsion unit, gear mechanism, fan, and tank system. As a result, no large forces need to be guided through the shroud any longer. Jet rudders in the flow behind the louvers 24 and 26 which deflect the main thrust vector for the roll control are not necessary.

It will be obvious to those skilled in the art that many modifications may be made within the scope of the present invention without departing from the spirit thereof, and the invention includes all such modifications.