Hostname: page-component-cd9895bd7-p9bg8 Total loading time: 0 Render date: 2024-12-22T11:05:24.340Z Has data issue: false hasContentIssue false
  • English
  • Français

Effects of blade configuration parameters on helicopter rotor structural dynamics and whirl tower loads

Published online by Cambridge University Press:  29 February 2016

M. Rohin Kumar  and
C. Venkatesan
M. Rohin Kumar*
Affiliation:
Department of Aerospace Engineering, Indian Institute of Technology, KanpurIndia
C. Venkatesan
Affiliation:
Department of Aerospace Engineering, Indian Institute of Technology, KanpurIndia
*
[email protected]
Get access Rights & Permissions [Opens in a new window]

Abstract

The influence of the blade geometric parameters on the structural dynamic characteristics, response and loads of a helicopter rotor under hover condition in a whirl tower was investigated. A general geometry was considered for the rotor blade which included configuration parameters like root offset, torque offset, pre-twist, pre-cone, pre-droop, pre-sweep, tip-sweep and tip-anhedral. The option of placing concentrated masses at any location on the blade was also included. Natural frequencies and the corresponding mode shapes of the rotating blade were obtained by solving the linear, undamped structural dynamics model in the finite element domain. For calculating the response and loads on the rotor, the complete aeroelastic equation was solved in modal space. Aerodynamic models used in the aeroelastic loads calculations were Peters-He dynamic wake theory for inflow and the modified ONERA dynamic stall theory for airloads calculations. From the study, the blade structural dynamic characteristics are found to be sensitive to variation in blade geometric parameters. Tip-sweep was found to have significant effects on root oscillatory moments. The moments at the tip junction with the straight portion of the blade were found to be substantially affected by tip-sweep and tip-anhedral.

Keywords

Structural DynamicsRotor LoadsRotary-wing Aeroelasticity
Type
Research Article
Information
The Aeronautical Journal , Volume 120 , Issue 1224 , February 2016 , pp. 271 - 290
Copyright
Copyright © Royal Aeronautical Society 2016 

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCES

1.Gupta, B.P.Blade Design Parameters which Affect Helicopter Vibrations. In Proceedings of the 40th AHS Annual Forum, 1984, Washington, DC, US.Google Scholar
2.Blackwell, R.H. Blade design for reduced helicopter vibration. J Am Helicopter Soc, 1983, 28, (3), pp 33–41.CrossRefGoogle Scholar
3.He, C. A parametric study of harmonic rotor hub loads. NASA Contractor Report 4558, 1993.Google Scholar
4.Laxman, V., Venkatesan, C. and Byun, Y.H.Influence of blade geometric parameters on aeroelastic response of a helicopter rotor system. J Aerospace Eng, 2011, 26, (3), pp 555–570.CrossRefGoogle Scholar
5.Götzfried, K.Survey of Tiger main rotor loads from design to flight test. J Am Helicopter Soc, 2002, 47, (4), pp 285–296.CrossRefGoogle Scholar
6.Pritchard, J.I., Adelman, H.M., Walsh, J.L. and Wilbur, M.L.Optimizing tuning masses for helicopter rotor blade vibration reduction and comparison with test data. J Aircraft, 1993, 30, (6), pp 906–910.CrossRefGoogle Scholar
7.Yoo, H.H., Seo, S. and Huh, K.The effect of a concentrated mass on the modal characteristics of a rotating cantilever beam. Proc Inst Mech Eng C, 2002, 216, (2), pp 151–163.CrossRefGoogle Scholar
8.Piccione, E., Bernardini, G. and Gennaretti, M.Structural aeroelastic finite element modeling for advanced-geometry rotor blades. Aircraft Eng Aerospace Technol, 2012, 84, (6), pp 367–375.CrossRefGoogle Scholar
9.Yen, J.G.Effects of blade tip shape on dynamics, cost, weight, aerodynamic performance, and aeroelastic response. J Am Helicopter Soc, 1994, 39, (4), pp 37–45.CrossRefGoogle Scholar
10.Celi, R. and Friedmann, P.Structural optimization with aeroelastic constraints of rotor blades with straight and swept tips. AIAA J, 1990, 28, (5), pp 928–936.CrossRefGoogle Scholar
11.Kim, K.C. and Chopra, I.Aeroelastic analysis of swept, anhedral, and tapered tip rotor blades. J Am Helicopter Soc, 1992, 37, (1), pp 15–30.CrossRefGoogle Scholar
12.Kumar, R. and Venkatesan, C.Rotorcraft aeroelastic analysis using dynamic wake/dynamic stall models and its validation. J Aeroelasticity Struct Dyn, 2013, 3, (1), pp 65–87.Google Scholar
13.Ginsberg, J.Engineering Dynamics, 2008, 10. Cambridge University Press.Google Scholar
14.Yuan, K.A., Venkatesan, C. and Friedmann, P.P. A new aeroelastic model for composite rotor blades with straight and swept tips. In 33rd AIAA Structural Dynamics and Materials Conference, AIAA 92-2259. April 1992, Dallas, Texas, US.CrossRefGoogle Scholar
15.Panda, B.Technical note: Assembly of moderate-rotation finite elements used in helicopter rotor dynamics. J Am Helicopter Soc, 1987, 32, (4), pp 63–69.CrossRefGoogle Scholar
16.Yuan, K.A., Venkatesan, C. and Friedmann, P.P. Structural dynamic model of composite rotor blades undergoing moderate deflections. In Recent Advances in the Structural Dynamic Modelling of Composite Rotor Blades and Thick Composites, ASME Ad-Vol. 30, Winter Annual Meeting of ASME Anaheim. November 1992, California, US.Google Scholar
17.Laxman, V. and Venkatesan, C.Chaotic response of an airfoil due to aeroelastic coupling and dynamic stall. AIAA J, 2007, 45, (1), pp 271–280.CrossRefGoogle Scholar
18.He, C.Development and Application of a Generalized Dynamic Wake Theory for Lifting Rotors. PhD thesis, Georgia Institute of Technology, July 1989, Atlanta, GA, US.Google Scholar
19.Petot, D. Differential equation modeling of dynamic stall. La Reserche Aerospatiale, (1989-5), pp 59-72.Google Scholar
20.GSL - GNU scientific library. http://www.gnu.org/software/gsl/.Google Scholar