Provided are a flap drive device and a rotorcraft blade, and more particularly, a flap drive device using a two-section link mechanism, which may be applied to a rotorcraft blade, and a rotorcraft blade including the same.

Provided are a flap drive device and a rotorcraft blade, and more particularly, a flap drive device using a two-section link mechanism, which may be applied to a rotorcraft blade, and a rotorcraft blade including the same.

A blade (1) having an outer covering (2) defining a cavity (8). A carriage (20) is arranged in said cavity (8), the carriage (20) being provided with a torsion bar (21) and at least two arms (22) secured to the torsion bar (21). The blade has one connection per arm provided both with an upstream guide gallery and with a downstream guide gallery, each arm extending transversely from an upstream end that slides in an upstream guide gallery to a downstream end that slides in a downstream guide gallery. At least one connection is a helical connection (40) obtained with the help of an upstream guide gallery (33) and the downstream guide gallery (34) of the segment (101) presenting distinct orientations, giving rise to movement in rotation (ROT1) of the segment (101) under the effect of the carriage (20) moving in translation.

A blade (1) having an outer covering (2) defining a cavity (8). A carriage (20) is arranged in said cavity (8), the carriage (20) being provided with a torsion bar (21) and at least two arms (22) secured to the torsion bar (21). The blade has one connection per arm provided both with an upstream guide gallery and with a downstream guide gallery, each arm extending transversely from an upstream end that slides in an upstream guide gallery to a downstream end that slides in a downstream guide gallery. At least one connection is a helical connection (40) obtained with the help of an upstream guide gallery (33) and the downstream guide gallery (34) of the segment (101) presenting distinct orientations, giving rise to movement in rotation (ROT1) of the segment (101) under the effect of the carriage (20) moving in translation.

A system and method for estimating rotor mixing commands for an aircraft includes receiving signals indicative of reference commands from one or more controllers; receiving signals indicative of airspeed and sideslip angle for the aircraft, the sideslip angle being indicative of a direction of flight for the aircraft; calculating a sine and cosine of the sideslip angle; determining gains for roll and pitch as a function of the airspeed, the determining including referencing a look-up table that indexes the gain constants with the airspeed; and determining the one or more rotor mixing commands from the determined gains, the one or more rotor mixing commands being applied synchronously to the rotors in the aircraft.

A system and method for estimating rotor mixing commands for an aircraft includes receiving signals indicative of reference commands from one or more controllers; receiving signals indicative of airspeed and sideslip angle for the aircraft, the sideslip angle being indicative of a direction of flight for the aircraft; calculating a sine and cosine of the sideslip angle; determining gains for roll and pitch as a function of the airspeed, the determining including referencing a look-up table that indexes the gain constants with the airspeed; and determining the one or more rotor mixing commands from the determined gains, the one or more rotor mixing commands being applied synchronously to the rotors in the aircraft.

A method of manufacturing a control cuff for a rotor blade of a hinge and bearingless rotor. The method comprises at least the steps of: manufacturing an outer shell, manufacturing a stiffener member by means of an automated process, inserting the stiffener member into the outer shell, and bonding the stiffener member to the outer shell.

A method of manufacturing a control cuff for a rotor blade of a hinge and bearingless rotor. The method comprises at least the steps of: manufacturing an outer shell, manufacturing a stiffener member by means of an automated process, inserting the stiffener member into the outer shell, and bonding the stiffener member to the outer shell.

A flow control method is a flow control method of controlling flow around a blade of a rotary wing, a plasma actuator being disposed at the blade. The flow control method includes: determining a characteristic frequency ratio that is a characteristic value among frequency ratios, each of the frequency ratios being a ratio between an actuator driving frequency and an angle of attack changing frequency, the actuator driving frequency being a frequency of an applied voltage applied to the plasma actuator, the angle of attack changing frequency being a frequency at which an angle of attack of the blade changes in accordance with a rotation angle of the blade; setting the actuator driving frequency such that the frequency ratio becomes the characteristic frequency ratio; and applying a voltage of the set actuator driving frequency to the plasma actuator to control the flow around the blade.

A self-latching piezocomposite actuator includes a plurality of shape memory ceramic fibers. The actuator can be latched by applying an electrical field to the shape memory ceramic fibers. The actuator remains in a latched state/shape after the electrical field is no longer present. A reverse polarity electric field may be applied to reset the actuator to its unlatched state/shape. Applied electric fields may be utilized to provide a plurality of latch states between the latched and unlatched states of the actuator. The self-latching piezocomposite actuator can be used for active/adaptive airfoils having variable camber, trim tabs, active/deformable engine inlets, adaptive or adjustable vortex generators, active optical components such as mirrors that change shapes, and other morphing structures.