Tunable blade assembly, a blade assembly, and a method of controlling vibration

A tunable blade assembly for a flight vehicle, the tunable blade assembly comprising:

• a hub rotatable about a central axis;
• a blade extending along a longitudinal axis between a root end and a tip end, with the tip end spaced from the hub, wherein the longitudinal axis is transverse to the central axis, wherein the blade is coupled to the hub at the root end such that the blade is rotatable concurrently with the hub and rotation of the blade generates vibrations in the blade, wherein the blade defines a cavity spaced from the tip end;
• a tunable control assembly including a mass adjustable inside of the cavity of the blade to reduce the vibrations in the blade;
• and
• wherein:
• the tunable control assembly includes a first wall disposed inside of the cavity to define a first boundary of the cavity that houses the mass;
• the tunable control assembly includes a second wall disposed inside of the cavity to define a second boundary of the cavity that houses the mass;
• the first wall and the second wall are spaced apart from each other to define a containment area, and the mass is disposed between the first wall and the second wall in the containment area;
• and
• the first wall and the second wall are movable relative to each other to change a location of the first boundary and a location of the second boundary inside of the cavity to change a volume of the containment area to accommodate a first adjusted mass or a second adjusted mass.

A tunable blade assembly for a flight vehicle, the tunable blade assembly comprising:

• a hub rotatable about a central axis;
• a blade extending along a longitudinal axis between a root end and a tip end, with the tip end spaced from the hub, wherein the longitudinal axis is transverse to the central axis, wherein the blade is coupled to the hub at the root end such that the blade is rotatable concurrently with the hub and rotation of the blade generates vibrations in the blade, wherein the blade includes a spar, the spar having a cavity spaced from the tip end;
• a tunable control assembly including a mass adjustable inside of the cavity of the blade to reduce the vibrations in the blade;
• and
• wherein:
• the mass includes a first mass portion formed of a fixed mass having a constant weight and a second mass portion formed of a fixed mass having a constant weight;
• the tunable control assembly includes a first actuator having a first connector coupled to the first mass portion, and the first actuator is configured to operate the first connector to move the first mass portion inside of the cavity axially relative to the longitudinal axis between the root end and the tip end;
• and
• the tunable control assembly includes a second actuator having a second connector coupled to the second mass portion, and the second actuator is configured to operate the second connector to move the second mass portion inside of the cavity axially relative to the longitudinal axis between the root end and the tip end.