Aeroelastic tuned mass damper
AssigneeThe Boeing Company
InventorsJack S. Hagelin, Sascha K. Ruegamer, Tim D. Thornton, Sean C. O'Meara, Jeffrey R. Ellis, E. Fred Gylland, JR.
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Abstract
A method for damping aeroelastic modes, including limit cycle oscillations (LCO), is implemented by determining a mass for a tuned mass damper (TMD) based on an modal frequency for a mode having a potentially positive growth rate and attaching a TMD to at least one attachment point with significant motion such that a damping axis of the tuned mass damper is substantially oriented in a direction aligned with the local modal deflection.
Claims18
A method for damping aeroelastic modes, including limit cycle oscillations (LCO), comprising:
- determining a mass for a tuned mass damper (TMD) based on an aeroelastic mode having a potentially positive growth rate;
- and,
- attaching at least one TMD to at least one attachment point such that a damping axis of the tuned mass damper is substantially oriented in a direction aligned with modal deflection at a location having significant modal deflection.
A method for configuration confirmation for damping aeroelastic modes with a TMD having a tuned mass assembly mounted on a shaft for reciprocal motion constrained with springs concentric to the shaft and viscous damping magnets on the tuned mass assembly with a metallic case concentrically surrounding the tuned mass assembly and magnets for eddy current generation comprising:
- determining a mass for the TMD based on a LCO flutter mode frequency having a potentially positive growth rate;
- adjusting the mass with tuning masses for a tuned mass assembly;
- attaching a TMD to an inlet bulkhead on each nacelle of an aircraft such that a damping axis of the tuned mass damper is substantially oriented in a direction aligned with modal deflection;
- supporting the TMD in a cantilevered position from the bulkhead;
- and,
- constraining the TMD with a lanyard cable.
An aeroelastic modal damping system comprising:
- at least one tuned mass assembly mounted to an aircraft attachment point for reciprocation on an axis oriented in an inboard and outboard direction;
- and,
- a viscous damper for the tuned mass.
An aircraft with an aeroelastic modal damping system comprising:
- a plurality of nacelles extending from the wings of an aircraft;
- a plurality of TMDs each having
- a tuned mass assembly with a primary mass concentrically mounted on a shaft with opposing concentric springs, the shaft supported by end caps;
- and,
- a viscous damper for the tuned mass having at least one magnet mounted on the tuned mass assembly and a case having a metallic surface mounted concentrically to the shaft adjacent the magnet for generation of eddy current;
- each TMD mounted to a respective one of the nacelles with the shaft on an axis oriented for reciprocation in an inboard and outboard direction.
Dependencies are inferred from the claim text.