Helicopter blade loads control via multiple trailing-edge flaps

Jun Sik Kim, Edward Smith, K. W. Wang

Research output: Contribution to journalConference article

2 Citations (Scopus)

Abstract

An active loads control strategy is proposed for the blade loads' reduction. The concept involves straightening the blade by introducing multiple trailing-edge flaps with I/rev control inputs for a four-bladed articulated rotor system. An aeroelastic model, which includes the quasi-steady blade aerodynamics with a linear inflow model and the classical incompressible theory for trailing-edge flaps, is used to explore the feasibility of blade loads control. An optimal control algorithm is derived for the defined objective function (including blade loads, vibratory hub loads and control efforts) to control both blade loads and vibration. Analytical studies are carried out for a steady-state forward flight condition. It is demonstrated that maximum flapping bending moment is reduced by up to 33%, and pitch-link loads' peak is reduced by up to 40%. For the rotor with cambered airfoils, pitch-link loads' peak can be reduced further by 81%. It is anticipated that a proposed control method could provide a solution of problems associated with the blade loads of heavy lift class helicopters or the pitch-link loads of the rotor with high cambered airfoils

Original languageEnglish (US)
Pages (from-to)1000-1010
Number of pages11
JournalAnnual Forum Proceedings - AHS International
VolumeII
StatePublished - Sep 14 2006
EventAHS Internaitonal 62nd Annual Forum - Phoenix, AZ, United States
Duration: May 9 2006May 11 2006

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Helicopters
Rotors
Airfoils
Straightening
Bending moments
Aerodynamics

All Science Journal Classification (ASJC) codes

  • Engineering(all)

Cite this

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title = "Helicopter blade loads control via multiple trailing-edge flaps",
abstract = "An active loads control strategy is proposed for the blade loads' reduction. The concept involves straightening the blade by introducing multiple trailing-edge flaps with I/rev control inputs for a four-bladed articulated rotor system. An aeroelastic model, which includes the quasi-steady blade aerodynamics with a linear inflow model and the classical incompressible theory for trailing-edge flaps, is used to explore the feasibility of blade loads control. An optimal control algorithm is derived for the defined objective function (including blade loads, vibratory hub loads and control efforts) to control both blade loads and vibration. Analytical studies are carried out for a steady-state forward flight condition. It is demonstrated that maximum flapping bending moment is reduced by up to 33{\%}, and pitch-link loads' peak is reduced by up to 40{\%}. For the rotor with cambered airfoils, pitch-link loads' peak can be reduced further by 81{\%}. It is anticipated that a proposed control method could provide a solution of problems associated with the blade loads of heavy lift class helicopters or the pitch-link loads of the rotor with high cambered airfoils",
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Helicopter blade loads control via multiple trailing-edge flaps. / Kim, Jun Sik; Smith, Edward; Wang, K. W.

In: Annual Forum Proceedings - AHS International, Vol. II, 14.09.2006, p. 1000-1010.

Research output: Contribution to journalConference article

TY - JOUR

T1 - Helicopter blade loads control via multiple trailing-edge flaps

AU - Kim, Jun Sik

AU - Smith, Edward

AU - Wang, K. W.

PY - 2006/9/14

Y1 - 2006/9/14

N2 - An active loads control strategy is proposed for the blade loads' reduction. The concept involves straightening the blade by introducing multiple trailing-edge flaps with I/rev control inputs for a four-bladed articulated rotor system. An aeroelastic model, which includes the quasi-steady blade aerodynamics with a linear inflow model and the classical incompressible theory for trailing-edge flaps, is used to explore the feasibility of blade loads control. An optimal control algorithm is derived for the defined objective function (including blade loads, vibratory hub loads and control efforts) to control both blade loads and vibration. Analytical studies are carried out for a steady-state forward flight condition. It is demonstrated that maximum flapping bending moment is reduced by up to 33%, and pitch-link loads' peak is reduced by up to 40%. For the rotor with cambered airfoils, pitch-link loads' peak can be reduced further by 81%. It is anticipated that a proposed control method could provide a solution of problems associated with the blade loads of heavy lift class helicopters or the pitch-link loads of the rotor with high cambered airfoils

AB - An active loads control strategy is proposed for the blade loads' reduction. The concept involves straightening the blade by introducing multiple trailing-edge flaps with I/rev control inputs for a four-bladed articulated rotor system. An aeroelastic model, which includes the quasi-steady blade aerodynamics with a linear inflow model and the classical incompressible theory for trailing-edge flaps, is used to explore the feasibility of blade loads control. An optimal control algorithm is derived for the defined objective function (including blade loads, vibratory hub loads and control efforts) to control both blade loads and vibration. Analytical studies are carried out for a steady-state forward flight condition. It is demonstrated that maximum flapping bending moment is reduced by up to 33%, and pitch-link loads' peak is reduced by up to 40%. For the rotor with cambered airfoils, pitch-link loads' peak can be reduced further by 81%. It is anticipated that a proposed control method could provide a solution of problems associated with the blade loads of heavy lift class helicopters or the pitch-link loads of the rotor with high cambered airfoils

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