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A technique to predict the aerodynamic effects of battle damage on an aircraft’s wing

Published online by Cambridge University Press:  27 January 2016

T.W. Pickhaver  and
P.M. Render
T.W. Pickhaver
Affiliation:
p.m.render@lboro.ac.uk, Loughborough University, Loughborough, UK
P.M. Render
Affiliation:
p.m.render@lboro.ac.uk, Loughborough University, Loughborough, UK
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Abstract

A technique is developed that can be used to predict the effects of battle damage on the aerodynamic performance of an aircraft’s wing. The technique is based on results obtained from wind tunnel tests on a NASA LS(1)-0417MOD aerofoil with simulated gunfire damage. The wind tunnel model incorporated an internal cavity to represent typical aircraft construction and this was located between 24% and 75% of chord. The damage was simulated by circular holes with diameters between 20% and 40% of chord. To represent different attack directions, the inclination of the hole axis relative to the aerofoil chord was varied between ±60° pitch and 45° of roll. The aerofoil spanned the wind tunnel to create approximate two-dimensional conditions and balance measurements were carried out at a Reynolds number of 500,000 for incidences, increased in 2° increments, from –4° to 16°. Surface flow visualisation and pressure measurements were also carried out. For a given hole size, the increments in lift, drag and pitching moment coefficients produced trends when plotted against the difference between the upper and lower surface pressure coefficients on the undamaged aerofoil taken at the location of the damage. These trends are used as the basis of the predictive technique. The technique is used to predict the effects of a previously untested damage case, and these are compared with wind tunnel tests carried out on a half model finite aspect ratio wing. For all coefficients the trends in the predicted data are similar to experiment, although there are some discrepancies in absolute values. For the drag coefficient these discrepancies are partly accounted for by limitations in the technique, whilst discrepancies in the lift and pitching moment coefficients are attributed to limitations in the aerofoil test arrangements.

Type
Research Article
Information
The Aeronautical Journal , Volume 119 , Issue 1218 , August 2015 , pp. 937 - 960
Copyright
Copyright © Royal Aeronautical Society 2015

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References

1.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, (1158), pp 469–484.CrossRefGoogle Scholar
2.Yang, Z., Samad-Suhaeb, M. and Render, P.M.. Computational Study of a Battle Damaged Finite Aspect Ratio Wing, 30th AIAA Applied Aerodynamics Conference, New Orleans, USA, pp 983–991, 2012.Google Scholar
3.Irwin, A.J. and Render, P.M.. The infuence of mid-chord battle damage on the aerodynamic characteristics of two-dimensional wings, Aeronaut J, March 2000, 104, (1033), pp 153–161.Google Scholar
4.Andreopoulos, J. and Rodi, W.. Experimental Investigation of jets in a crossflow, J Fluid Mechanics, 138, 1984.CrossRefGoogle Scholar
5.Mahesh, K.. The interaction of jets with crossflow, Annual Review of Fluid Mechanics, 45, pp 379–407, 2013. DODI 10.1146/annurev-fluid-120710-101115CrossRefGoogle Scholar
6.Irwin, A.J. and Render, P.M.. The Infuence of Internal Structure on the Aerodynamic Characteristics of Battle Damaged Wings, 14th AIAA Applied Aerodynamic Conference Proceedings, Paper 1996-2395, 1996.Google Scholar
7.Render, P.M., de Silva, s., Walton, A.J. and Mahmoud, M.. Experimental investigation into the aerodynamic effects of battle damaged airfoils, AIAA J Aircraft, 2007, 44, (2), pp 539–549. DOI 10.2514/1.24144Google Scholar
8.Robinson, K.W. and Leishman, J.G.. Effects of ballistic damage on the aerodynamics of helicopter rotor airfoils, AIAA J Aircr, 1998, 33, (5), pp 695–703.Google Scholar
9.Render, P.M., Samad-Suhaeb, M., Yang, Z. and Mani, M.. Aerodynamics of battle-damaged fnite-aspect ratio wings, 2009, AIAA J Aircr, 46, (3), pp 997–1004. DOI: 102514/1.39839.CrossRefGoogle Scholar
10.Render, P.M. and Pickhaver, T.W.. The Influence of Hole Orientation on the Aerodynamics of a Battle Damaged Wing, 30th AIAA Applied Aerodynamics Conference Proceedings, pp 800–813, 2012.Google Scholar
11.Pickhaver, T.W. and Render, P.M.. A Technique to Predict the Aerodynamic Losses of Battle Damaged Wings, 28th Congress of the International Council of the Aeronautical Sciences Proceedings, 2012, 2, pp 914–928.Google Scholar
12.McGhee, R.J. and Beasley, W.D.. Wind-tunnel results for a modified 17-percent-thick low-speed airfoil section, NASA Technical Paper 1919, 1981.Google Scholar
13.Lift Interference and Blockage Corrections for Two-Dimensional Subsonic Flow in Ventilated and Closed Wind Tunnels, Engineering Sciences Data Unit, Data sheet ESDU 76028, 1995.Google Scholar
14.Garner, H.C., Rogers, E.W.E., Acum, W.E.A. and Maskell, e.c., Subsonic Wind Tunnel Corrections, Technical Report AGARDograph 109, AGARD, October 1966.Google Scholar
15.Compton, D.A. and Johnston, J.P.. Streamwise vortex production by pitched and skewed jets in a turbulent boundary layer, AIAA J, 1992, 30, (3), pp 640–647.CrossRefGoogle Scholar
16.Milanovic, I.M. and Zaman, K.B.. M.Q. Fluid dynamics of highly pitched and yawed jets in crossflow, AIAA J, 2004, 42, (5), pp 874–882.CrossRefGoogle Scholar
17.Irwin, A.J.. Investigation into the Aerodynamic Effects of Simulated Battle Damage to a Wing, PhD Thesis, Loughborough University, UK, 1999.Google Scholar
18.Pickhaver, T. W.. Prediction and Validation of the Aerodynamic Effects of Simulated Battle Damage on Aircraft Wings, PhD Thesis, Loughborough University, UK, 2013.Google Scholar
19.Upwash Interference for Wings in Solid-liner Wind Tunnels using Subsonic Linearised-Theory, Engineering Sciences Data Unit, Data sheet ESDU 95014, 1995.Google Scholar