Hostname: page-component-cd9895bd7-dzt6s Total loading time: 0 Render date: 2024-12-26T16:29:13.400Z Has data issue: false hasContentIssue false
  • English
  • Français

The influence of simulated missile warhead fragment damage on the aerodynamic characteristics of two-dimensional wings

Published online by Cambridge University Press:  27 January 2016

A. J. Irwin  and
P. M. Render
A. J. Irwin
Affiliation:
BAE Systems Warton, UK
P. M. Render*
Affiliation:
Department of Aeronautical and Automotive Engineering, Loughborough University, Loughborough, UK
*
[email protected]
Get access Rights & Permissions [Opens in a new window]

Abstract

The paper describes a method of representing damage on a wing due to multiple warhead fragments, and investigates two of the key variables: fragment impact density and hole diameter. The aerodynamic effects of the damage were quantified by wind-tunnel tests on a two-dimensional wing at a Reynolds number of 5 × 105. The wing was of hollow construction with leading and trailing-edge spars. In all of the cases tested, simulated fragment damage resulted in significant lift losses, drag increases and pitching moment changes. Increasing fragment density or hole size resulted in greater effects. To a first order approximation, both lift and drag increments at a given incidence were related to the percentage wing area removed. Surface flow visualisation showed that low fragment densities and small damage sizes resulted in a complex flow structure on the surface of the wing. This was made up of boundary-layer growth between the damage holes, attached wakes from the forward damage holes and separated surface flow over the rear of the wing. For these cases, individual hole patterns showed similar flow mechanisms to those seen for larger scale gunfire damage cases. Increased fragment density and hole size resulted in upper surface flow separation at the first row of holes. Behind this separation, the flow was attached and consisted of the combined wakes from the forward damage holes. Investigations into the influence of internal model structure indicated that trends in coefficient changes were similar for both hollow and solid wings. However, the magnitudes of the effects were found to be smaller for hollow wings than for solid wings.

Type
Research Article
Information
The Aeronautical Journal , Volume 117 , Issue 1194 , August 2013 , pp. 823 - 837
Copyright
Copyright © Royal Aeronautical Society 2013 

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. Irwin, A.J. and render, P.M. Infuence of mid-chord battle damage on aerodynamic characteristics of two-dimensiona wings, Aeronaut J, March 2000, 104, (1033), pp 153–161.Google Scholar
2. Render, P.M., de Silva, S, Walton, A.J. and Mahmoud, M. Experimental investigation into the aerodynamics of battle damaged airfoils, J Aircr, 2007, 44, (2), pp 539–549.Google Scholar
3. Render, P.M., Samad-Suhaeb, M., Yang, Z. and Mani, M. Aerodynamics of battle damaged finite-aspectratio wings, J Aircr, June 2009, 46, (3), pp 997–1004.Google Scholar
4. Saeedi, M., Ajalli, F. and Mani, M. A Comprehensive numerical study of battle damage and repairs upon the aerodynamic characteristics of an aerofoil, Aeronaut J, 2010, 114, pp 469–484.Google Scholar
5. Survivability aircraft non-nuclear, General criteria, 1982, MIL-HDBK-336-1, Vol 1.Google Scholar
6. UK Defence Standard 00-970 Part 13 Design and airworthiness requirements for service aircraft, Section 3, 2011.Google Scholar
7. Addendum to design manual for impact damage tolerant aircraft structure, 1988, AGARD-AG-238 (Addendum).Google Scholar
8. Kagerbauer, G. ET AL. Improvement of battle damage tolerance for composite structures, 1986, AGARD Report 729 — Impact Damage to Composite Structures.Google Scholar
9. Garner, H.C. ET AL. Subsonic wind tunnel wall corrections, AGARDograph, October 1986, 109.Google Scholar
10. Loftin, L.K. and smith, H.A. Aerodynamic characteristics of 15 NACA airfoil sections at seven Reynolds numbers from 0·7 x l06 to 9·0 × l06, 1945, Technical Note, National Advisory Committee for Aeronautics.Google Scholar
11. Irwin, A.J and Render, P.M. The influence of internal structure on the aerodynamic characteristics of battle damaged wings, 1996, Paper 96-2395, 14th AIAA Applied Aerodynamics Conference.Google Scholar
12. Render, P.M and Walton, A. Aerodynamics of battle damaged wings — The influence of flaps camber and repair schemes, 2005, Paper 2005-4721, 23rd AIAA Applied Aerodynamics Conference.Google Scholar
13. Pickhaver, T. and Render, P.M. A technique to predict the aerodynamic losses of battle damaged wings, 2012, Paper ICAS 2012-3.2.2, 28th International Congress of the Aeronautical Sciences.Google Scholar