Hostname: page-component-cb9f654ff-w5vf4 Total loading time: 0 Render date: 2025-08-17T13:10:50.543Z Has data issue: false hasContentIssue false
  • English
  • Français

Dynamic inflow modelling for autorotatingrotors

Published online by Cambridge University Press:  03 February 2016

Y. Murakami  and
S.S. Houston
Y. Murakami
Affiliation:
University of Glasgow, Glasgow, UK
S.S. Houston
Affiliation:
University of Glasgow, Glasgow, UK
Get access Rights & Permissions [Opens in a new window]

Abstract

The dynamic inflow model is a powerful tool forpredicting the induced velocity distribution over arotor disc. On account of its closed form andsimplicity, the model is especially practical forstudying flight mechanics or for designing controlsystems for helicopters. Scant attention has,however, been paid so far in utilising the dynamicinflow model to analyse an autorotating rotor, whichis different from a powered rotor in the geometricrelation between the direction of the inflow and therotor disc. Autorotation is an abnormal conditionfor helicopters, but for gyroplanes it is the normalmode of operation. Therefore the theoreticaldiscussion on an autorotating rotor is of importancenot only to improve the understanding of presentgyroplanes, but also in the development of newgyroplanes and to analyse the windmill-brake stateof helicopters. Dynamic inflow modelling is reviewedfrom first principles, and this identifies amodification to the mass flow parameter. Aqualitative assessment of this change indicates thatit is likely to have a negligible impact on the trimstate of rotorcraft in autorotation, but asignificant effect on the dynamic inflow modes incertain flight conditions. This is confirmed bynumerical simulation, although considerabledifferences only become apparent for steep descentswith low forward speed. It is concluded that whilemodification of the mass flow parameter is perhapsmathematically accurate, for practical purposes itis required only in a limited area of the flightenvelope of autorotating rotorcraft.

Information

Type
Research Article
Information
The Aeronautical Journal , Volume 112 , Issue 1127 , January 2008 , pp. 47 - 53
Copyright
Copyright © Royal Aeronautical Society 2008 

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.)

Article purchase

Temporarily unavailable

References

1. Peters, D. and Su, S., The effect of hidden dynamic states on floquet eigenvalues, J American Helicopter Soc, October 1990, TN, 35, (4), pp 72–75.Google Scholar
2. Peters, D.A. and He, C.-J., Finite state induced flow models part II: three-dimensional rotor disk, J Aircr, March-April 1995, 32, (2), pp 323–333.Google Scholar
3. 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.Google Scholar
4. 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.Google Scholar
5. Sissingh, G.J., The effect of induced velocity variation on helicopter rotor damping in pitch or roll, Aeronautical Research Council, ARC TR G.P. No 101, November 1952.Google Scholar
6. Johnson, W., Influence of unsteady aerodynamics on hingeless rotor ground resonance, J Aircr, August 1982, 29, (9), pp 668–673.Google Scholar
7. Chen, R.T., A survey of nonuniform inflow models for rotorcraft flight dynamics and control applications, Vertica, 1990, 14, (2), pp 147–184 Google Scholar
8. Gaonkar, G.H. and Peters, D.A., Review of dynamic inflow modeling for rotorcraft flight dynamics, Vertica, 1988, 12, (3), pp 213–242.Google Scholar
9. Pitt, D.M. and Peters, D.A., Theoretical prediction of dynamic-inflow derivatives, Vertica, January 1981, 5, (1), pp 21–34.Google Scholar
10. Houston, S.S., Analysis of rotorcraft flight dynamics in autorotation, J Guidance, Control and Dynamics, January-February 2002, 25, (1), pp 33–39.Google Scholar
11. Houston, S.S., Modeling and analysis of helicopter flight mechanics in autorotation, J Aircr, 40, (4), July-August 2003, pp 675–682.Google Scholar
12. Houston, S.S. and Brown, R.E., Rotor-wake modelling for simulation of helicopter flight mechanics in autorotation, J Aircr, September 2003, 40, (5), pp 938–945.Google Scholar
13. Peters, D.A. and He, C.-J.N., Modification of mass-flow parameter to allow smooth transition between helicopter and windmill states, J American Helicopter Soc, TN, July 2006, 51, (3), pp 275–278.Google Scholar
14. He, C.-J.,. Lee, C.S. and Chen, W., Finite state induced flow model in vortex ring state, J American Helicopter Soc, October 2000, TN, 45, (4), pp 318–320.Google Scholar
15. Done, G. and Balmford, D., Bramwell’s Helicopter Dynamics, 2nd ed. Butterworth Heinemann, 2001, pp 44.Google Scholar
16. Peters, D.A. and Haquang, N., Dynamic inflow for practical applications, J American Helicopter Soc, TN, October 1988, 33, (4), pp 64–68 Google Scholar
17. He, C.J., Development and Application of a Generalised Dynamic Wake Theory for Lifting Rotors, PhD dissertation, Georgia Inst of Tech, USA, 1989.Google Scholar
18. Houston, S.S., Validation of a non-linear individual blade rotorcraft flight dynamics model using a perturbation method, Aeronautp J, August-September 1994, 98, (977), pp 260–266.Google Scholar
19. Houston, S.S., Validation of a rotorcraft mathematical model for autogyro simulation, J Aircr, 38, (3), 2000, pp 203–209.Google Scholar
20. Houston, S.S. and Tarttelin, P.C., Validation of mathematical simulations of helicopter vertical response characteristics in hover, J American Helicopter Society, 36, (1), 1991, pp 45–57.Google Scholar
21. Padfield, G.D., Helicopter Flight Dynamics, Blackwell Science, Oxford, 1996, pp 264–267.Google Scholar
22. Leishman, J.D., Principles of Helicopter Aerodynamics, 2nd ed. Cambridge University Press, 2006, pp 692–720.Google Scholar
23. Groen Brothers Aviation Incorporated. Company Webpage, 2006, http://www.groenbros.com Google Scholar