Embedded absorbers for helicopter rotor lag damping

被引:23
作者
Byers, Lynn [1 ]
Gandhi, Farhan [1 ]
机构
[1] Penn State Univ, Dept Aerosp Engn, Vert Lift Res Ctr Excellence, University Pk, PA 16802 USA
关键词
OPTIMIZED AEROELASTIC COUPLINGS; ELASTOMERIC DAMPER MODEL; AEROMECHANICAL STABILITY; GROUND RESONANCE; ALLEVIATION; AIR;
D O I
10.1016/j.jsv.2009.03.031
中图分类号
O42 [声学];
学科分类号
070206 ; 082403 ;
摘要
Radial and chordwise damped vibration absorbers embedded in the rotor blade are compared for rotor lag damping augmentation. Results show that the radial absorber is more effective in transferring damping to the rotor blade lag mode. The chordwise absorber needs to be at a more outboard location and have a larger mass to introduce levels of lag damping comparable to that introduced by the radial absorber. The 1/rev amplitude of a chordwise absorber at the blade tip, per degree of blade lead-lag motion in forward flight, is of the order of 35% of the blade chord, and such a stroke might be difficult to accommodate. The 1/rev amplitude of a radial absorber at 70% span (having significantly lower mass than the chordwise absorber and producing comparable lag damping) is of the order of 4% of the rotor blade span. The static displacement of the radial absorber under centrifugal load needs to be limited using a frequency-dependent (high static stiffness, low dynamic stiffness) or nonlinear spring. The chordwise absorber can also undergo a large static displacement under the chordwise component of the centrifugal load if there is an offset from the feather axis, and this would again have to be limited using a strategy such as a frequency-dependent spring. Significant advantages of the radial absorber are-higher lag damping, lower absorber mass, space for absorber mass travel, and no chordwise travel of blade center of gravity reducing susceptibility to aeroelastic instability and dynamic pitch-link loads. (C) 2009 Elsevier Ltd. All rights reserved.
引用
收藏
页码:705 / 721
页数:17
相关论文
共 32 条
[1]  
Bousman W.G., 1981, Journal of the American Helicopter Society, V26, P46, DOI [10.4050/JAHS.26.1.46, DOI 10.4050/JAHS.26.1.46]
[2]   Application of a refined time domain elastomeric damper model to helicopter rotor aeroelastic response and stability [J].
Brackbill, CR ;
Smith, EC ;
Lesieutre, GA .
JOURNAL OF THE AMERICAN HELICOPTER SOCIETY, 2002, 47 (03) :186-197
[3]  
Byers L.K., 2006, THESIS PENNSYLVANIA
[4]   Low frequency vertical geometric anti-spring vibration isolators [J].
Chin, EJ ;
Lee, KT ;
Winterflood, J ;
Ju, L ;
Blair, DG .
PHYSICS LETTERS A, 2005, 336 (2-3) :97-105
[5]  
CHOPRA I, 1990, VERTICA, V14, P457
[6]  
FELKER FF, 1987, J AM HELICOPTER SOC, V32
[7]   Analysis of bearingless main rotor aeroelasticity using an improved time domain nonlinear elastomeric damper model [J].
Gandhi, F ;
Chopra, I .
JOURNAL OF THE AMERICAN HELICOPTER SOCIETY, 1996, 41 (03) :267-277
[8]   ANALYTICAL MODEL FOR A NONLINEAR ELASTOMERIC LAG DAMPER AND ITS EFFECT ON AEROMECHANICAL STABILITY IN HOVER [J].
GANDHI, F ;
CHOPRA, I .
JOURNAL OF THE AMERICAN HELICOPTER SOCIETY, 1994, 39 (04) :59-69
[9]   Optimized aeroelastic couplings for alleviation of helicopter ground resonance [J].
Gandhi, F ;
Hathaway, E .
JOURNAL OF AIRCRAFT, 1998, 35 (04) :582-590
[10]   Magnetorheological fluid damper feedback linearization control for helicopter rotor application [J].
Gandhi, F ;
Wang, KW ;
Xia, LB .
SMART MATERIALS & STRUCTURES, 2001, 10 (01) :96-103