Flow Control and High-Lift Performance for Flying-Wing Unmanned Combat Air Vehicle Configurations by inserting slots

U Ali, E Chadwick

Abstract


The objectives of the present study on Unmanned Combat Air Vehicles (UCAVs) are two-fold: first to control the flow by inserting leading-edge and cross-flow slots and analysing the viscous flow development over the outer panels of a flying-wing configuration to maximise the performance of the elevons control surfaces; second to predict high-lift performance particularly the maximum-lift characteristics. This is demonstrated using a variety of inviscid Vortex Lattice Method (VLM) and Euler, and viscous CFD Reynolds Averaged Navier-Stokes (RANS) methods. The computational results are validated against experiment measured in a wind tunnel. Two flying-wing planforms are considered based around a generic 40˚ edge-aligned configuration. The VLM predicts a linear variation of lift and pitching moment with incidence angle, and substantially under-predicts the induced drag. Results obtained from RANS and Euler agree well with experiment. 


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References


Schütte, A., D. Hummel, and S.M. Hitzel, Flow Physics Analyses of a Generic Unmanned Combat Aerial Vehicle Configuration. Journal of Aircraft, 2012. 49(6): p. 1638-1651. CrossRef

Bertin, J.J., Aerodynamics for Engineers. 4th ed. 2002, USA: Prentice Hall.

Gudmundsson, S., Chapter 9 - The Anatomy of the Wing, in General Aviation Aircraft Design, S. Gudmundsson, Editor. 2014, Butterworth-Heinemann: Boston. p. 299-399. CrossRef

Frink, N.T., M. Tormalm, and S. Schmidt, Three Unstructured Computational Fluid Dynamics Studies on Generic Unmanned Combat Aerial Vehicle. Journal of Aircraft, 2012. 49(6): p. 1619-1637. CrossRef

Shevell, R.S., Fundamentals of Flight. 2nd ed. 1989, New Jersey: Prentice Hall.

Buchholz, M.D. and J. Tso, Lift Augmentation on Delta Wing with Leading-Edge Fences and Gurney Flap. Journal of Aircraft, 2000. 37(6): p. 1050-1057. CrossRef

Anderson, D.F., Understanding flight. 2nd ed. ed, ed. S. Eberhardt. 2010, New York: New York : McGraw-Hill.

Kermode, A.C., Mechanics of flight. 12th ed / rev. by R.H. Barnard and D.R. Philpott. ed, ed. R.H. Barnard and D.R. Philpott. 2012, New York: Pearson Education.

Gudmundsson, S., Chapter 10 - The Anatomy of Lift Enhancement, in General Aviation Aircraft Design, S. Gudmundsson, Editor. 2014, Butterworth-Heinemann: Boston. p. 401-457. CrossRef

Coppin, J., Aerodynamics, Stability and Shape Optimisation of Unmanned Combat Air Vehicles, in Department of Mechanical Engineering. 2014, University of Sheffield.

Robert, N., et al., Modification of the Flow Structure over a UAV Wing for Roll Control, in 45th AIAA Aerospace Sciences Meeting and Exhibit. 2007, American Institute of Aeronautics and Astronautics. CrossRef

Anderson, J.D., Fundamentals of Aerodynamics. 2010, Boston: McGraw-Hill Education.

Wilson, H.A. and J.C. Lovell, Full-scale Investigation of the Maximum Lift and Flow Characteristics of an Airplane Having Approximately Triangular Plan Form. 1947.

Earnshaw, P.B., An experimental investigation of the structure of a leading-edge vortex, M.o. Aviation, Editor. 1961.

Polhamus, E.C., Predictions of vortex-lift characteristics based on a leading-edge suction analogy, in 6th Annual Meeting and Technical Display. 1969, American Institute of Aeronautics and Astronautics. CrossRef

Elkhoury, M. and D. Rockwell, Visualized Vortices on Unmanned Combat Air Vehicle Planform: Effect of Reynolds Number. Journal of Aircraft, 2004. 41(5): p. 1244-1247. CrossRef

Kingsley, S. and S. Quegan, Understanding Radar Systems. 1992, Berkshire: Mcgraw-Hill.

Jenn, D.C., Radar and laser cross section engineering. 1995, Washington, DC: American Institute of Aeronautics and Astronautics.

Johnston, L.J., High-Lift Aerodynamics of Uninhabited Combat Air Vehicle Configurations with Reduced Radar Cross-Section Characteristics, in RAES Applied Aerodynamics Conference. July 2012: Bristol.

Gad-el-Hak, M., Flow Control: Passive, Active, and Reactive Flow Management. 2000, New York: Cambridge University Press. CrossRef

Lachmann, G., Results of Experiments with Slotted Wings. 1924, NACA.

Johnson, R.W., The handbook of fluid dynamics. 1998, Heidelberg: Springer-Verlag.




DOI: http://dx.doi.org/10.21152/1750-9548.10.2.117

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