Abstract
The use of active, internally blown high-lift flaps causes the reduction of the stall angle of attack, because of the strong suction peak generated at the leading-edge. This problem is usually addressed by employing movable leading-edge devices, which improve the pressure distribution, increase the stall angle of attack, and also enhance the maximum lift coefficient. Classical leading-edge devices are the hinged droop nose or the more effective slat with a gap. The flow distortions generated by the gap become an important source of noise during approach and landing phases. Based on these considerations, the present work aims at evaluating the potentials of gap-less droop nose devices designed for improving the aerodynamics of airfoils with active high lift. Both conventional leading-edge flaps and flexible droop noses are investigated. Flexible droop nose configurations are obtained by smoothly morphing the baseline leading-edge shape. Increasing the stall angle of attack and reducing the power required by the active high-lift system are the main objectives. The sensitivities of the investigated geometries are described, as well as the physical phenomena that rule the aerodynamic performance. The most promising droop nose configurations are compared with a conventional slat device as well as with the clean leading-edge. The response of the different configurations to different blowing rates and angles of attack are compared and the stalling mechanisms are analyzed.
































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Wild, J.: Mach and Reynolds number dependencies of the stall behavior of high-lift wing-sections. J. Aircr. 50(4), 1202–1216 (2013)
Radespiel, R., Heinze, W.: SFB 880: Fundamentals of High-Lift for Future Commercial Aircraft. Deutscher Luft- und Raumfahrtkongress, Stuttgart (2013)
Werner-Spatz, C., Heinze, W., Horst, P., Radespiel, R.: Multidisciplinary conceptual design for aircraft with circulation control high-lift systems. CEAS Aeronaut. J. 3, 145–164 (2012)
Pott-Pollenske, M., Alvarez-Gonzalez, J., Dobrzynski, W.: Effect of slat gap on farfield radiated noise and correlation with local flow characteristic. 9th AIAA/CEAS Aeroacoustics Conference, Hilton Head (SC), AIAA 2003-3228
Nielsen, J.N., Biggers, J.C.: Recent progress in circulation control aerodynamics, AIAA Paper 87-001, (1987)
Greenblatt, D., Wygnanski, I.: The control of flow separation by periodic excitation. PERGAMON Prog. Aerosp. Sci. 36, 487–545 (2000)
Yaros, S.F., et al.: Synergistic Airframe-Propulsion Interactions and Integrations, NASA/TM-1998-207644, (1998)
Joslin, R.D., Jones, G.S.: Applications of Circulation Control Technology. Progress in Astronautics and Aeronautics, vol. 214, AIAA, (2006)
Gad El Hak: Flow Control: Passive, Active, and Reactive Flow Management. Cambridge University Press, England (2000)
Englar, R.J.: Overview of circulation control pneumatic aerodynamics: blown force and moment augmentation and modification as applied primarily to fixed-wing aircraft. In: Joslin, D., Jones, G.S. (eds.) Applications of Circulation Control Technology, Progress in Astronautics and Aeronautics, vol. 214, pp. 23–68, AIAA, (2006)
Milholen, W., Jones, G., Chan, D.: High-Reynolds number circulation control testing in the national transonic facility (Invited). 50th AIAA Aerospace Sciences Meeting, AIAA 2012-0103
Allan, B., Jones, G., Lin, J.: Reynolds-Averaged Navier-Stokes simulation of a 2D circulation control wind tunnel experiment, 49th AIAA Aerospace Sciences Meeting, Orlando (FL), AIAA 2011-25
Paschal, K., Neuhart, D., Beeler, G., Allan, B.: Circulation Control Model Experimental Database for CFD Validation, 50th AIAA Aerospace Sciences Meeting, Nashville (TN), AIAA 2012-0705
Pott-Pollenske, M., Pfingsten, K.-C.: Aeroacoustic Performance of an Airfoil with Coanda Control, 16th AIAA/CEAS Aeroacoustics Conference, AIAA 2010-3881, (2010)
Schwier, W.: Auftriebsanderung Durch einen auf der Flugeldruckseite Ausgeblasene Luftstrahl, UM31912, (1944)
Poisson-Quinton, Ph, Lepage, L.: Survey of French research on the control of boundary layer and circulation. In: Lachmann, G.V. (ed.) Boundary Layer and Flow Control: its Principles and Application, vol. 1, pp. 21–73. Pergamon, New York (1961)
Radespiel, R., Pfingsten, K.-C., Jensch, C.: Flow analysis of augmented high-lift systems, In: Radespiel, R., Rossow, C.-C., Brinkmann, B. (eds.) Hermann Schlichting––100 Years. Scientific Colloquium Celebrating the Anniversary of his Birthday, Braunschweig, Germany 2007. Notes on Numerical Fluid Mechanics and Multidisciplinary Design, vol. 102, Springer, ISBN978-3-540-95997-7, (2009)
Thomas, F.: Untersuchungen über die Grenzschichtbeeinflussung durch Ausblasen zur Erhöhung des Auftriebes, Dissertation, Institut für Strömungsmechanik, TU Braunschweig, 1961. Gekürzte Fassung: Z. Flugwiss. vol. 10, pp. 46–65, (1962)
Gersten, K., Löhr, R.: Untersuchungen über die Auftriebserhöhung eines Tragflügels bei gleichzeitigem Ausblasen an der Hinterkantenklappe und an der Profilnase, Institutsbericht 62/34, Institut für Strömungsmechanik der Technischen Universität Braunschweig, (1962)
Englar, R.J., Huson, G.G.: Development of advanced circulation control using high-lift airfoils. J. Aircr. 21(7), 476–483 (1984)
Jensch, C., Pfingsten, K.C., Radespiel, R., Schuermann, M., Haupt, M., Bauss, S.: Design Aspects of a Gapless High-Lift System with Active Blowing. DLRK 2009, Aachen (2009)
Englar, R.J., Smith, M.J., Kelley, S.M., Rover II, R.C.: Development of circulation control technology for application to advanced subsonic transport aircraft. J. Aircr. 31(7), 1160–1177 (1994)
Greenblatt, D.: Dual Location Separation Control on a Semi-Span Wing, 23rd AIAA Applied Aerodynamics Conference, Toronto, Ontario Canada (2005)
Jensch, C., Pfingsten, K.C., Radespiel, R.: Numerical investigation of leading edge blowing and optimization of the slot and flap geometry for a circulation control airfoil. Notes on Numerical Fluid Mechanics and Multidisciplinary Design, vol. 112. Springer, Heidelberg (2010)
Seifert, A.: Delay of airfoil stall by periodic excitation. J Aircr, vol. 33, no. 4, July–August (1996)
Kühn, T., Wild, J.: Aerodynamic optimization of a two-dimensional two-element high lift airfoil with a smart droop nose device, 1st EASN Association Workshop on Aerostructures. Paris, France (2010)
Shmilovich, A., Yadlin, Y.: Flow control for the systematic buildup of high lift systems. 3rd AIAA Flow Control Conference, San Francisco (CA), AIAA 2006-2855
Shmilovich, A., Yadlin, Y.: Flow control techniques for transport aircraft. AIAA J. 49, 489–502 (2011)
Ying, S.X., Spaid, F.W., McGinley, C.B., Rumsey, C.L.: Investigation of confluent boundary layers in high-lift flows, AIAA Paper 1998-2622, (1998)
Jirásek, A., Amoignon, O.: Design of a high-lift system with a droop nose device. J. Aircr. 46, 731–734 (2009)
Burnazzi, M., Radespiel, R.: Design and analysis of a droop nose for coanda flap applications. J. Aircr. (2014). doi:10.2514/1.C032434
Pfingsten, K.C., Jensch, C., Körber, K.V., Radespiel, R.: Numerical simulation of the flow around circulation control airfoils. First CEAS European Air and Space Conference, Berlin (2007)
Swanson, R.C., Rumsey, C.L.: Computation of circulation control airfoil flows. Comput. Fluids 38, 1925–1942 (2009)
Pfingsten, K.C., Cecora, R.D., Radespiel, R.: An experimental investigation of a gapless high-lift system using circulation control. Katenet II Conference, Bremen (2009)
Pfingsten, K.C., Radespiel, R.: Experimental and numerical investigation of a circulation control airfoil. 47th AIAA Aerospace Sciences Meeting, Orlando, AIAA 2009-533
Kroll, N., Rossow, C–.C., Schwamborn, D., Becker, K., Heller, G.: MEGAFLOW––A Numerical Flow Simulation Tool for Transport Aircraft Design. ICAS Congress, Toronto (2002)
Schamborn, D., Gerhold, T., Heinrich, R.: The DLR TAU-Code: Recent Applications in Research and Industry. ECCOMAS CFD, Egmond aan Zee (2006)
Shur, M.L., Strelets, M.K., Travin, A.K., Spalart, P.R.: Turbulence modeling in rotating and curved channels: assessing the spalart-shur correction. AIAA J. 38, 784–792 (2000)
Richardson, L.F.: The deferred approach to the limit. Trans. Royal. Soc. Lond. Series A 226, 299–361 (1927)
Raymer, D.P.: Aircraft design: a conceptual approach. AIAA Educ. Ser., (1999)
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The funding of this work of the Collaborative Research Centre SFB 880 by the German Research Foundation, DFG, is thankfully acknowledged.
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Burnazzi, M., Radespiel, R. Assessment of leading-edge devices for stall delay on an airfoil with active circulation control. CEAS Aeronaut J 5, 359–385 (2014). https://doi.org/10.1007/s13272-014-0112-5
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DOI: https://doi.org/10.1007/s13272-014-0112-5