Hostname: page-component-8448b6f56d-42gr6 Total loading time: 0 Render date: 2024-04-19T13:50:18.228Z Has data issue: false hasContentIssue false
  • English
  • Français

Asymptotic Expansion for Transient Forces from Quasi-Steady Subsonic Wing Theory

Published online by Cambridge University Press:  07 June 2016

H. C. Garner  and
R. D. Milne
Get access

Summary

A simple general expression is obtained for the rate of change of generalised aerodynamic damping coefficients with respect to frequency parameter in the limit as frequency tends to zero. The expression is directly proportional to aspect ratio and does not depend explicitly on Mach number. The result is consistent with calculated pitching derivatives from finite-frequency theory.

This extension of quasi-steady theory is applied to determine the leading transient term of the asymptotic expansion for large time of generalised forces due to an indicial upwash field. The expansion has direct relevance to the use of quasi-steady aerodynamic derivatives in the field of stability and control.

Type
Research Article
Information
Aeronautical Quarterly , Volume 17 , Issue 4 , November 1966 , pp. 343 - 350
Copyright
Copyright © Royal Aeronautical Society. 1966

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. Watkins, C. E., Runyan, H. L. and Woolston, D. S. On the kernel function of the integral equation relating the lift and downwash distributions of oscillating finite wings in subsonic flow. NACA Report 1234, 1955.Google Scholar
2. Garner, H. C. Multhopp’s subsonic lifting-surface theory of wings in slow pitching oscillations. ARC R & M 2885, 1952.Google Scholar
3. Lawrence, H. R. and Gerber, E. H. The aerodynamic forces on low aspect ratio wings oscillating in an incompressible flow. Journal of the Aeronautical Sciences, Vol. 19, p. 769, 1952.Google Scholar
4. Acum, W. E. A. Theory of lifting surfaces oscillating at general frequencies in a stream of high subsonic Mach number. ARC Report 17 824, 1956.Google Scholar
5. Carslaw, H. S. and Jaeger, J. C. Operational methods in applied mathematics, Chap. IV. (Second Edition.) Oxford University Press, 1947.Google Scholar
6. Milne, R. D. The role of flutter derivatives in aircraft stability and control. Presented at the AGARD Flight Mechanics Panel Specialists’ Meeting on Stability and Control, Cambridge, 20th-23rd September 1966.Google Scholar