Hostname: page-component-cd9895bd7-jkksz Total loading time: 0 Render date: 2024-12-25T17:29:08.728Z Has data issue: false hasContentIssue false
  • English
  • Français

The Effect of Chordwise Flexibility on the Lift of a Rapidly Accelerated Airfoil

Published online by Cambridge University Press:  07 June 2016

J. Katz  and
D. Weihs
J. Katz
Affiliation:
Department of Aeronautical Engineering Technion - Israel Institute of Technology, Haifa
D. Weihs
Affiliation:
Department of Aeronautical Engineering Technion - Israel Institute of Technology, Haifa
Get access

Summary

The effects of finite chordwise flexibility on the development of lift on a rapidly started airfoil are studied. This is a generalization of the so-called Wagner problem of unsteady aerodynamics. It is found that the lift varies with time in a non-monotonous fashion, including more than one extremum. The lift at large times is found to be lower, the more flexible the foil. Changes in the wake vortex sheet are also discussed.

Type
Research Article
Information
Aeronautical Quarterly , Volume 30 , Issue 1 , February 1979 , pp. 360 - 370
Copyright
Copyright © Royal Aeronautical Society. 1979

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 Wagner, H. Uber die Entstehung des dynamischen Auftriebes von Tragflugeln, z.f.a.M.M, Vol. 5, No. 1, February 1925, pp 17–35 Google Scholar
2 Von Karman, T. and Sears, W.R. Airfoil Theory for Non-uniform Motion, Journal of the Aeronautical Sciences, Vol. 5, No. 10, August 1938, pp 379–390 Google Scholar
3 Drischler, J.A. Approximate Indicial Lift Functions for Several Wings of Finite Span in Incompressible Flow as Obtained from Oscillatory Lift Coefficient, NACA TN 3639, May 1956 Google Scholar
4 Dore, B.D. Phil, D. and The Unsteady Forces on Finite Wings in Transient Motion, A.R.C. R. & M. Rep. No. 3456, September 1964Google Scholar
5 Giesing, J.P. Nonlinear Two Dimensional Unsteady Potential Flow with Lift, Journal of Aircraft, Vol. 5, No. 2, 1968, pp 135–143 CrossRefGoogle Scholar
6 Djojodihardjo, R.H. and Widnall, S.E. A Numerical Method for the Calculation of Norllinear, Unsteady Lifting Potential Flow Problems, AIM Journal, Vol. 7, No. 10, October 1969, pp 2001–2009 Google Scholar
7 Lomax, H. Indicial Aerodynamics, AGARD, Manual on Aeroelasticity, Part 2, Chapter 6.Google Scholar
8 Lighthill, M.J. Hydromechanics of Aquatic Animal Propulsion, Annual Review of Fluid Mechanics, Vol. 1, 1969, pp 413–446 Google Scholar
9 Wu, T.Y. Hydromechanics of Swimming Propulsion, Part 1: Swimming of a Two Dimensional Flexible Plate at Variable Forward Speeds in an Inviscid Fluid, Journal of Fluid Mechanics, Vol. 46, Part 2, 1971, pp 337–365 CrossRefGoogle Scholar
10 Wortmann, F.X. The Quest for High-Lift, AIM Paper No. 74-1018, September 1974 Google Scholar
11 Katz, J. and Weihs, D. Forces Due to Large Amplitude Oscillations of an Airfoil with Chordwise Flexibility, J. Fluid Mechanics, Vol. 88, 1978, pp 485–497 CrossRefGoogle Scholar
12 Fink, P.T. Soh, W.K. and A New Approach to Roll-up Calculations of Vortex Sheets, Proc. R. Soc. Lond A362, 1978, pp 195–209 Google Scholar