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Flexible rotor blade dynamics for helicopter aeromechanics including comparisons with experimental data

Published online by Cambridge University Press:  27 January 2016

I. Goulos ,
V. Pachidis  and
P. Pilidis
V. Pachidis
Affiliation:
School of Aerospace, Transport and Manufacturing, Cranfield University, Bedford, UK
P. Pilidis
Affiliation:
School of Aerospace, Transport and Manufacturing, Cranfield University, Bedford, UK
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Abstract

This paper presents the development of a mathematical model for the implementation of flexible rotor blade dynamics in real-time helicopter aeromechanics applications. A Lagrangian approach is formulated for the rapid estimation of natural vibration characteristics of nonuniform rotor blades. A matrix/vector formulation is proposed for the treatment of elastic blade kinematics in the time-domain. In order to overcome the classical hurdles of time-accurate simulation and establish applicability in real-time, a novel, second-order accurate, finite-difference scheme is employed for the numerical discretisation of elastic blade motion. The proposed rotor dynamics model is coupled with a finite-state induced flow and an unsteady blade element aerodynamics model. The combined formulation is implemented in a helicopter flight mechanics simulation code. The integrated approach is deployed in order to investigate rotor blade resonant frequencies, trim control angles, oscillatory blade loads and induced vibration for a hingeless and an articulated helicopter rotor. Extensive comparisons are carried out with wind tunnel and flight test measurements, and non-real-time comprehensive analysis methods. Good agreement with measured data is exhibited considering primarily the low-frequency harmonic components of oscillatory loading. It is shown that, the developed methodology can be utilised for real-time simulation on a typical computer with sufficient modelling fidelity for accurate estimation of oscillatory blade loads.

Type
Research Article
Information
The Aeronautical Journal , Volume 119 , Issue 1213 , March 2015 , pp. 301 - 342
Copyright
Copyright © Royal Aeronautical Society 2015

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References

1.Johnson, W.Rotorcraft Aeromechanics, First ed, 2013, Cambridge University Press, Cambridge, UK.CrossRefGoogle Scholar
2.Johnson, W. Milestones in rotorcraft aeromechanics, 2011, NASA Ames Research Center, TP-2011-215971.Google Scholar
3.Padfield, G.D.Helicopter Flight Dynamics, 2007, Blackwell Publishing, Oxford, UK.CrossRefGoogle Scholar
4.Howlett, J.J. UH-60A Black Hawk engineering simulation program: I, Mathematical model, 1981, NASA, CR 166309.Google Scholar
5.Shupe, N. A Study on the dynamic motions of hingeless rotored helicopters, 1970, US Army Electronics Command, TR ECOM-3323.Google Scholar
6.Curtiss, H. and Shupe, N.A Stability and control theory for hingeless rotors, 1971, Proceedings of the 27th Annual Forum of the American Helicopter Society, May 1971, Washington, DC, USA.Google Scholar
7.Brown, R.E.Rotor wake modelling for flight dynamic simulation of helicopters, AIAA J, January 2000, 38, (1), pp 57–63.CrossRefGoogle Scholar
8.Johnson, W.Rotorcraft aerodynamics models for a comprehensive analysis, Proceedings of the 54th Annual Forum of the American Helicopter Society, May 1998, Washington, DC, USA.Google Scholar
9.Brown, R.E. and Houston, S.S.Comparison of induced velocity models for helicopter flight mechanics, J Aircr, August 2000, 37, (4), pp 623–629.CrossRefGoogle Scholar
10.Pitt, D.M. and Peters, D.A.Theoretical prediction of dynamic inflow derivatives, Vertica, March 1981, 5, (1), pp 21–34.Google Scholar
11.Peters, D.A. and Haquang, N.Dynamic inflow for practical applications, J American Helicopter Soc, October 1988, 33, (4), pp 64–68.CrossRefGoogle Scholar
12.Theodore, C. and Celi, R. Helicopter flight dynamic simulation with refined aerodynamics and flexible blade modelling, 2000, 56th Annual Forum of the American Helicopter Society, 2-4 May 2000.Google Scholar
13.Kim, F.D., Celi, R. and Tischler, M.B.High-order state space simulation models of helicopter flight mechanics, J American Helicopter Soc, October 1993, 38, (4), pp 16–27.CrossRefGoogle Scholar
14.Turnour, S.R. and Celi, R.Modelling of flexible rotor blades for helicopter flight dynamics applications, J American Helicopter Soc, January 1996, 41, (1), pp 52–66.CrossRefGoogle Scholar
15.Bagai, A. and Leishman, J.G.Rotor free-wake modelling using a pseudo-implicit technique - including comparisons with experimental data, J American Helicopter Soc, April 1995, 40, (3), pp 29–41.CrossRefGoogle Scholar
16.Lewis, W.D.An aeroelastic model structure investigation for a manned real-time rotorcraft simulation, 49th Annual Forum of the American Helicopter Society, May 1993, Saint Louis, MO, USA.Google Scholar
17.Sturisky, S.H. and Schrage, D.P.System identification validation of an AH-64 aeroelastic simulation model, 1993, 49th Annual Forum of the American Helicopter Society, May 1993, Saint Louis, MO, USA.Google Scholar
18.Yeo, H. and Johnson, W.Prediction of rotor structural loads with comprehensive analysis, J American Helicopter Soc, April 2008, 53, (2), pp 193–209.CrossRefGoogle Scholar
19.Piziali, R.A. and DuWaldt, F.A. A method for computing rotary wing airload distribution in forward flight, 1962, Cornell Aeronautical Laboratory, TCREC TR 62-44.CrossRefGoogle Scholar
20.Piziali, R. and DuWaldt, F.Computed induced velocity, induced drag, and angle of attack distributions for a two-bladed rotor, 1963, 19th Annual Forum of the American Helicopter Society, May 1963, Washington, DC, USA.Google Scholar
21.Piziali, R., Daughaday, H. and DuWaldt, F.Rotor airloads, 1963, CAL/TRECOM Symposium on Dynamic Load Problems Associated with Helicopters and V/STOL Aircraft, June 1963, Buffalo, NY, USA.Google Scholar
22.Piziali, R. A method for predicting the aerodynamic loads and dynamic response of rotor blades, January 1966, USAAVLABS, TR 65-74.CrossRefGoogle Scholar
23.Piziali, R.Method for the solution of the aeroelastic response problem for rotating wings, J Sound and Vibration, November 1966, 4, (3), pp 445–489.CrossRefGoogle Scholar
24.Yeo, H. and Johnson, W.Assessment of comprehensive analysis calculation of airloads on helicopter rotors, J Aircr, September 2005, 42, (5), pp 1218–1228.CrossRefGoogle Scholar
25.Yeo, H. and Johnson, W.Comparison of rotor structural loads calculated using comprehensive analysis, 2005, 31st European Rotorcraft Forum, September 2005, Florence, Italy.Google Scholar
26.Johnson, W.Technology drivers in the development of CAMRAD II, 1994, American Helicopter Society Aeromechanics Specialists’ Conference, January 1994, San Fransisco, CA, USA.Google Scholar
27.Johnson, W.General free wake geometry calculation for wings and rotors, 1995, 51st Annual Forum of the American Helicopter Society May 1995, Fort Worth, TX, USA.Google Scholar
28.Johnson, W.Rotorcraft dynamics models for a comprehensive analysis, 1998, 27th Annual Forum of the American Helicopter Society, May 1998, Washington, DC, USA.Google Scholar
29.Peters, D.A., Boyd, D.D. and He, C.J.Finite-state induced-flow model for rotors in hover and forward flight, J American Helicopter Soc, October 1989, 34, (4), pp 5–17.CrossRefGoogle Scholar
30.Peters, D.A. and He, C.J.Correlation of measured induced velocities with a finite-state wake model, J American Helicopter Soc, July 1991, 36, (3), pp 59–70.CrossRefGoogle Scholar
31.van der Wall, B.G., Lim, J.W., Smith, M.J., Jung, S.N., Bailly, J., Baeder, J.D. and Boyd, D.D.The HART II International Workshop: An assessment of the state-of-the-art in comprehensive code prediction, CEAS Aeronaut J, July 2013, 4, (3), pp 223–252.CrossRefGoogle Scholar
32.van der Wall, B.G.A comprehensive rotary-wing database for code validation: The HART II International Workshop, Aeronaut J, February 2011, 115, (1164), pp 91–102.CrossRefGoogle Scholar
33.Johnson, W.A.History of rotorcraft comprehensive analyses, 2013, 69th Annual Forum of the American Helicopter Society, May 2013, Phoenix, AZ, USA.Google Scholar
34.Johnson, W. and Datta, A.Requirements for next generation comprehensive analysis of rotorcraft, 2008, AHS Specialist’s Conference on Aeromechanics, 23-25 January 2008, San Francisco, CA, USA.Google Scholar
35.van der Wall, B.G. and Roth, M.Free-wake analysis on massively parallel computers and validation with HART test data, 1997, 53rd Annual Forum of the American Helicopter Society, 29 April-1 May 1997, Virginia Beach, VA, USA.Google Scholar
36.Hu, Q., Gumerov, N.A., Duraiswami, R. and Leishman, M.S.J.G.Toward improved aeromechanics simulations using recent advancements in scientific computing, 2011, 67th Annual Forum of the American Helicopter Society, 3-5 May 2011, Virginia Beach, VA, USA.Google Scholar
37.Bhagwat, M.J. and Leishman, J.G.Stability, consistency and convergence of time-marching free-vortex rotor wake algorithms, J American Helicopter Soc, January 2001, 46, (1), pp 59–71.CrossRefGoogle Scholar
38.Johnson, W. CAMRAD/JA, A Comprehensive Analytical Model of Rotorcraft Aerodynamics and Dynamics Vol I: Theory Manual, 1988, Johnson Aeronautics, Palo Alto, CA, USA.Google Scholar
39.Johnson, W.A Comprehensive Analytical Model of Rotorcraft Aerodynamics and Dynamics Vol II: User Manual, 1988, Johnson Aeronautics, Palo Alto, CA, USA.Google Scholar
40.Bisplinghoff, R.L., Ashley, H. and Halfman, R.L.Aeroelasticity, 1996, Dover Publications, Mineola, New York, NY, USA.Google Scholar
41.Goulos, I., Pachidis, V. and Pilidis, P.Lagrangian formulation for the rapid estimation of helicopter rotor blade vibration characteristics, Aeronaut J, August 2014, 118, (1206).CrossRefGoogle Scholar
42.Bramwell, A.R.S.Done, G. and Balmford, D.Bramwell’s Helicopter Dynamics, 2001, Butterworth-Heinemann, Oxford, UK.Google Scholar
43.Leishman, J.G. and Beddoes, T.S.A semi-empirical model for dynamic stall, J American Helicopter Soc, July 1989, 34, (3), pp 3–17.Google Scholar
44.Noonan, K.W. and Bingham, G.J. Two-dimensional aerodynamic characteristics of several rotorcraft aerofoils at Mach numbers from 0·35 to 0·90 January 1977, NASA Langley Research Center, TM X-73990.Google Scholar
45.Staley, J.A. Validation of rotorcraft flight simulation program through correlation with flight data for soft-in-plane hingeless rotor, 1976, USAAMRDL-TR-75-50.CrossRefGoogle Scholar
46.Bousman, W.G., Young, C., Toulmay, F., Gilbert, N.E., Strawn, R.C., Miller, J.V., Costes, T.H.M.M. and Beaumier, P. A Comparison of lifting-line and CFD methods with flight test data from a research Puma helicopter, 1996, NASA, TM-110421.Google Scholar
47.Padfield, G.D., Basset, P.M., Dequin, A.M., von Grunhagen, W., Haddon, D., Haverdings, H., Kampa, K. and McCallum, A.T.Predicting rotorcraft flying qualities through simulation modelling. A review of key results from Garteur AG06, September 1996, 22nd European Rotorcraft Forum, Brighton, UK.Google Scholar
48.Peterson, R.L., Maier, T., Langer, H.J. and Tranapp, N.Correlation of wind tunnel and flight test results of a full-scale hingeless rotor, January 1994, American Helicopter Society Aeromechanics Specialist Conference, San Francisco, CA, USA.Google Scholar
49.Drela, M. XFOIL: An Analysis and Design System for Low Reynolds Number Airfoils, Low Reynolds Number Aerodynamics, Mueller, T. (Ed), Lecture Notes in Engineering, 1989, 54 pp 1–12, Springer Berlin, Heidelberg, Germany.Google Scholar