A study of the flight dynamics helicopter carrying an external load using bifurcation theory and continuation methods

Sibilski, K.

Artykuł - szczegóły

Tytuł artykułu

A study of the flight dynamics helicopter carrying an external load using bifurcation theory and continuation methods

Autorzy

Sibilski K.

Treść / Zawartość

Pełne teksty:

Pobierz

Identyfikatory

Warianty tytułu

Studium dynamiki lotu śmigłowca z podwieszonym ładunkiem z wykorzystaniem teorii bifurkacji i metod kontynuacyjnych

Języki publikacji

Abstrakty

The paper presents a study of the flight dynamics of a helicopter with an articulated rotor, carrying a suspended load. The aircraft model includes rigid body dynamics, individual flap and blade dynamics, and inflow dynamics. The load is a point mass with a single suspension point. Results are obtained for load masses of up to 1500 kg, with load-to-helocopter mass rations up to 33%, and cable lengths up to 55m. The presence of the external load modifies the flight dynamics and handling quality characteristics of the helicopter because the dynamic and aerodynamic characteristics of the load may make it unstable in certain fight conditions. Maneuvers of this system in wide flight regimes involves non-linear aerodynamics and inertial coupling. In can be stated that the helicopter with the suspended load is a inherently non-linear and time varying system. Theory of dynamical systems provides a methodology for studying such non-linear systems. Bifurcation theory is a part of that theory. It considers changes in the stability of the system which lead to qualitatively different responses of it. In this paper, results from the theory of dynamical systems are used to predict the nature of instabilities caused by bifurcations and the response of the rotorcraft with the suspended load that follow such bifurcations.

W pracy przedstawiono studium dynamiki lotu śmigłowca z przgubowym wirnikiem nośnym, przenoszącego podwieszony pod kadłubem ładunek. W zastosowanym modelu wiropłata uwzględniono stopnie swobody nieodkształcalnego kadłuba, dynamikę wahań i odchyleń łopat wirnika nośnego oraz dynamikę przepływu przez płaszczyznę wirnika nośnego. Założono, że podwieszony ładunek jest punktem materialnym, na który działają siły aerodynamiczne, podwieszonym w jednym punkcie pod kadłubem śmigłowca. Wyniki obliczeń uzyskano dla podwieszonych ładunków o masie do 1500kg (stosunek masy ładunku do masy śmigłowca do 35%), podwieszonych na linie o długości do 55m. Obecność podwieszonego ładunku modyfikuje charakterystyki dynamiczne i osiągi śmigłowca ze względu na silne sprzężenia aerodynamiczne i bezwładnościowe pomiędzy jego ruchem a ruchami śmigłowca. Ze względu na fakt, że układ śmigłowiec-podwieszony ładunek jest opisany za pomocą silnienieliniowych zwyczajnych równań różniczkowych, zastosowanie klasycznej analizy modalnej układu nie zawsze jest możliwe. Doskonałych narzędzi do badania takich równań dostarcza teoria układów dynamicznych i będąca jej częścią teoria bifurkacji. W pracy wykorzystano metodologię teorii układów dynamicznych do prognozowania natury niestabilności spowodowanej występującymi bifurkacjami. Ponadto przeprowadzono symulacje ruchu układu śmigłowiec-podwieszony ładunek po wystąpieniu bifurkacji.

Słowa kluczowe

non-linear helicopter dynamics bifurcation theory continuation method

Wydawca

Polskie Towarzystwo Mechaniki Teoretycznej i Stosowanej

Czasopismo

Journal of Theoretical and Applied Mechanics

Rocznik

2003

Tom

Vol. 41 nr 4

Strony

823--852

Opis fizyczny

Bibliogr. 41 poz., rys.

Twórcy

autor

Sibilski K.

krzysztof.sibilski@pwr.wroc.pl

Department of Aeronautical Engineering, Wrocław University of Technology and Air Force Institute of Technology, Warsaw

Bibliografia

1. Aeronautical Design Standard ADS-33D, Handling Qualities Requirements for Military Rotorcraft, U.S. Army Aviation and Troop Command, St. Louis, MO, July 1994
2. Arczewski K., Pietrucha J., 1993, Mathematical Modelling of Complex Mechanical Systems, E. Horwood, Chichester
3. Avanzini G., De Matteis G., 1998, Bifurcation analysis of a highly augmented aircraft model, Journal of Guidance, Control & Dynamics, 20, 1
4. Carroll J.V., Mehra R.K., 1982, Bifurcation analysis of non-linear aircraft dynamics, Journal of Guidance Control and Dynamics, 5, 5
5. Cicolani L.S., Kanning G., Synnestvedt R., 1995, Simulation of the dynamics of helicopter slung load systems, Journal of the American Helicopter Society, 40, 4, 44-61
6. Cicolani L.S., McCoy A.H., Tischler M.B., Tucker G.E., Gatenio P., Marmar D., 1998, Flight-time identification of a UH-60A helicopter and slung load, Proceedings of the NATO RTA Symposium on System Identification, Madrid, Spain, 10.1-10.18
7. Cliff E.M., Bailey D.B., 1975, Dynamic stability of a translating vehicle with a simple sling load, Journal of Aircraft, 12, 10, 773-777
8. Doedel E., Kernevez J.P., 1986, AUTO – Software for Continuation and Bifurcation Problems in Ordinary Differential Equations, Caltech, Pasadena
9. Dukes T.A., 1973a, Manoeuvring heavy sling loads near hover. Part I: Damping the pendulous motion, Journal of the American Helicopter Society, 18, 2, 2-11
10. Dukes T.A., 1973b, Manoeuvring heavy sling loads near hover. Part II: Some elementary manoeuvres, Journal of the American Helicopter Society, 18, 3, 17-22
11. Ermentrout B., 2001, XPPAUT5.41 – the Differential Equations Tool, Caltech, Pasadena
12. Etkin B., 1972, Dynamics of Atmospheric Flight, John Willey, N. York
13. Fusato D., Guglieri G., Celi R., 1999, Flight dynamics of an articulated rotor helicopter with an external slung load, Proceedings of the 55-th Annual Forum AHS, Montreal, Canada
14. Gabel R., Wilson G.J., 1968, Test approaches to external sling load instabilities, Journal of the American Helicopter Society, 13, 3, 44-55
15. Guicheteau P., 1990, Bifurcation theory in flight dynamics an application to a real combat aircraft, ICAS-90-5.10.4, Proceedings of 17th ICAS Congress, Stockholm, Sweden
16. Gutowski R., 1972, Analytical Mechanics, PWN, Warsaw
17. Hassard B.D., Kazarinoff N.D., Wan Y.H., 1981, Theory and Applications of Hopf Bifurcation, Cambridge University Press
18. Ioos G., Joseph D., 1980, Elementary Stability and Bifurcation Theory, Springer-Verlag, New York
19. Jahnke C.C., Culick F.E.C., 1994, Application of bifurcation theory to the high-angle-of-attack dynamics of the F-14, Journal of Aircraft, 31, 1, 26-34
20. Keller H.B., 1977, Numerical Solution of Bifurcation and Nonlinear Eigenvalue Problems, Application of Bifurcation Theory, Academic Press, N. York
21. Krotophalli K.R., Prasad J.V.R., Peters D.A., 1999, Helicopter rotor dynamics inflow modelling for manoeuvring flight, Proc. 55th Annual Forum ofthe AHS, Montreal, Canada
22. Lucassen L.R., Sterk F.J., 1965, Dynamic stability analysis of a hovering helicopter with a sling load, Journal of the American Helicopter Society, 10, 2, 6-12
23. Łucjanek W., Sibilski K., 1978, Longitudinal dynamic stability of a hovering helicopter with a hanging load, Journal of Applied and Theoretical Mechanics, 17, 2, 264-276
24. Marsden J.E., McCracken M., 1976, The Hopf bifurcation and its applications, Applied Mathematical Science, 19, Springer Verlag, New York
25. Marusak A.J., Pietrucha J.A., Sibilski K.S., 2000, Prediction of aircraft critical flight regimes using continuation and bifurcation methods, AIAA Paper, AIAA-2000-0976, 38th Aerospace Sciences Meeting and Exhibit, Reno, NV
26. Nagabhushan B.L., 1985, Low-speed stability characteristics of a helicopter with a sling load, Vertica, 9, 345-361
27. Narkiewicz J., 1994, Rotorcraft eeromechanical and aeroelastic stability, Scientific Works of Warsaw University of Technology, Issue Mechanics, 158
28. Pitt D.M., Peters D.A., 1981, Theoretical prediction of dynamic inflow derivatives, Vertica, 5, 1
29. Poli C., Cromack D., 1973, Dynamics of slung bodies using a single-point suspension system, Journal of Aircraft, 10, 2, 80-86
30. Sheldon D.F., 1977, An appreciation of the dynamic problems associated with the external transportation of loads from a helicopter state of the art, Vertica, 1, 281-290
31. Sibilski K., 1980, Dynamic stability of a single rotor helicopter carrying a suspended payload, PhD Thesis, Warsaw University of Technology, Warsaw
32. Sibilski K., 1998, Modelling of agile aircraft dynamics in limiting flight conditions, Rep. No. 2557/98, Military University of Technology, Warsaw
33. Sibilski K., 1999a, Bifurcation analysis of a helicopter non-linear dynamics, The Archive of Mechanical Engineering, 44, 2, 171-192
34. Sibilski K., 1999b, Nonlinear flight mechanics of a helicopter analysis by application of continuation methods, Proceedings of the 25th European Rotorcraft Forum, Paper no. H-4, Roma, Italy
35. Sibilski K., 2000, An agile aircraft non-linear dynamics by continuation methods and bifurcation theory, ICAS-3.11.2, Proceedings of the 22nd ICAS Congress, Harrogate, UK
36. Sibilski K., Łucjanek W., 1983, Dynamic stability of a helicopter with a suspended load, The Archive of Mechanical Engineering, 30, 3-4, 249-267
37. Simpson A., Flower J.W., 1981, Lateral flutter of loads towed beneath helicopters and its avoidance, Vertica, 5, 337-356
38. Szustak L. S., Jenney D., 1971, Control of large crane helicopters, Journal of the American Helicopter Society, 16, 3, 11-22
39. Tang D.M., Dowell E.H., 1998, Unsteady eerodynamic forces and aeroelastic response for external store of an aircraft, J. of Aircraft, 35, 5
40. Tran C.T., Petot D., 1981, Semi-empirical model for the dynamic stall of airfoils in view of the application to the calculation of responses of a helicopter rotor blade in forward flight, Vertica, 5
41. Wiggins S., 1990, Introduction to Applied Nonlinear Dynamical Systems and Chaos, Springer-Verlag, New York

Typ dokumentu

Bibliografia

Identyfikator YADDA

bwmeta1.element.baztech-article-BWM2-0015-0074