Hostname: page-component-848d4c4894-2pzkn Total loading time: 0 Render date: 2024-05-26T08:29:28.468Z Has data issue: false hasContentIssue false

Modelling the flight dynamics of the hang glider

Published online by Cambridge University Press:  03 February 2016

M. V. Cook
Affiliation:
Dynamics, Simulation and Control Group, Department of Aerospace Sciences, School of Engineering, Cranfield University, Bedfordshire, UK
M. Spottiswoode
Affiliation:
Dynamics, Simulation and Control Group, Department of Aerospace Sciences, School of Engineering, Cranfield University, Bedfordshire, UK

Abstract

The development of the non-linear equations of motion for the hang glider from first principles is described, including the complex geometry of control by pilot ‘weight shift’. By making appropriate assumptions the linearised small perturbation equations are derived for the purposes of stability and control analysis. The mathematical development shows that control is effected not by pilot weight shift, but by centre of gravity shift and that lateral-directional control by this means is weak, and is accompanied by significant instantaneous adverse response.

The development of a comprehensive semi-empirical mathematical model of the flexible wing aerodynamics is described. In particular, the modelling attempts to quantify camber and twist dependencies. The performance of the model is shown to compare satisfactorily with measured hang glider wing data obtained in earlier full scale experiments. The mathematical aerodynamic model is then used to estimate the hang glider stability and control derivatives over the speed envelope for substitution into the linearised equations of motion.

Solution of the equations of motion is illustrated and the flight dynamics of the typical hang glider are described. In particular, the dynamic stability properties are very similar to those of a conventional aeroplane, but the predicted lateral directional stability margins are significantly larger. The depth of mathematical modelling employed enables the differences to be explained satisfactorily. The unique control properties of the hang glider are described in some detail. Pitch and roll control of the hang glider is an aerodynamic phenomenon and results from the pilot adjusting his position relative to the wing in order to generate out of trim aerodynamic control moments about the centre of gravity. Maximum control moments are limited by hang glider geometry which is dependent on the length of the pilot‘s arm. The pilot does not generate control moments directly by shifting his weight relative to the wing. The modelling thus described would seem to give a plausible description of the flight dynamics of the hang glider.

Type
Research Article
Copyright
Copyright © Royal Aeronautical Society 2005 

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

1. Kilkenny, E.A.. An Experimental Study of the Longitudinal Aerodynamic and Static Stability Characteristics of Hang Gliders, 1986, PhD thesis, College of Aeronautics, Cranfield Institute of Technology.Google Scholar
2. Kilkenny, E.A.. An evaluation of a mobile aerodynamic test facility for hang glider wings, November 1983, College of Aeronautics Report 8330, Cranfield Institute of Technology.Google Scholar
3. Cook, M.V. and Kilkenny, E.A.. An experimental investigation of the aerodynamics of the hang glider, 1986, Paper No 25, Proceedings of an International Conference on Aerodynamics at low Reynolds numbers, October 1986, Royal Aeronautical Society, London.Google Scholar
4. Kilkenny, E.A. Full scale wind tunnel tests on hang glider pilots, 1984, College of Aeronautics Report 8416, Cranfield Institute of Technology.Google Scholar
5. Blake, D.M.. Modelling the aerodynamics, stability and control of the hang glider, 1991, MSc thesis, College of Aeronautics, Cranfield Institute of Technology.Google Scholar
6. Cook, M.V.. The theory of the longitudinal static stability of the hang-glider, Aeronaut J, October 1994, 98, (978), pp 292304.Google Scholar
7. Powton, J.N.. A Theoretical Study of the Non-linear Aerodynamic Pitching Moment Characteristics of the Hang Glider and its Influence on Stability and Control, 1995, MSc thesis, College of Aeronautics, Cranfield University.Google Scholar
8. Rollins, R.. Study of Experimental Data to Assess the Longitudinal Stability and Control of the Hang Glider, 2000, MSc thesis, College of Aeronautics, Cranfield University.Google Scholar
9. Spottiswoode, M.. A Theoretical Study of the Lateral-directional Dynamics, Stability and Control of the Hang Glider, 2001, MSc thesis, College of Aeronautics, Cranfield University.Google Scholar
10. Kroo, I.. Aerodynamics, Aeroelasticity and Stability of Hang Gliders, 1983, PhD thesis, Stanford University.Google Scholar
11. De Matteis, G. Response of hang gliders to control, Aeronaut J, October 1990, 94, (938), pp 289294.Google Scholar
12. De Matteis, G. Dynamics of hang gliders, AIAA J Guidance, Control and Dynamics, November-December 1991, 14, (6).Google Scholar
13. Cook, M.V., Flight Dynamics Principles, 1997, Arnold, London.Google Scholar
14. Sweeting, J.T.. An Experimental Investigation of Hang Glider Stability, 1981, MSc thesis, College of Aeronautics, Cranfield University.Google Scholar
15. Nickel, K and Wohlfahrt, M., Tailless Aircraft, 1990, Ch 9, pp 385420, Edward Arnold, London.Google Scholar
16. ESDU: Validated engineering data — Aerodynamics series, Engineering Sciences Data, Data Items 79006 and 90010, ESDU International, London.Google Scholar