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An active back-flow flap for a helicopter rotor blade

  • Opitz, Steffen (German Aerospace Center (DLR), Institute of Composite Structures and Adaptive Systems) ;
  • Kaufmann, Kurt (German Aerospace Center (DLR), Institute of Aerodynamics and Flow Technology) ;
  • Gardner, Anthony (German Aerospace Center (DLR), Institute of Aerodynamics and Flow Technology)
  • Received : 2013.06.18
  • Accepted : 2013.11.01
  • Published : 2014.01.31

Abstract

Numerical investigations are presented, which show that a back-flow flap can improve the dynamic stall characteristics of oscillating airfoils. The flap was able to weaken the stall vortex and therefore to reduce the peak in the pitching moment. This paper gives a brief insight into the method of function of a back-flow flap. Initial wind tunnel experiments were performed to define the structural requirements for a detailed experimental wind tunnel characterization. A structural integration concept and two different actuation mechanisms of a back-flow flap for a helicopter rotor blade are presented. First a piezoelectric actuation system was investigated, but the analytical model to estimate the performance showed that the displacement generated is too low to enable reliable operation. The seond actuation mechanism is based on magnetic forces to generate an impulse that initiates the opening of the flap. A concept based on two permanent magnets is further detailed and characterized, and this mechanism is shown to generate sufficient impulse for reliable operation in the wind tunnel.

References

  1. Mai, H., Dietz, G., Geissler, W., Richter, K., Bosbach, J., Richard, H. and de Groot, K. (2008), "Dynamic stall control by leading edge vortex generators", J. Am. Helicopter Soc. 53(1), 26-36. https://doi.org/10.4050/JAHS.53.26
  2. Martin, P., Wilson, J., Berry, J., Wong, T., Moulton, M. and McVeigh, M. (2008), "Passive control of compressible dynamic stall", AIAA 2008-7506.
  3. LePape, A., Costes, M., Joubert, G., David, F. and Deluc, J.M. (2012), "Experimental study of dynamic stall control using deployable leading-edge vortex generators", AIAA J, 50(10), 2135-2145. https://doi.org/10.2514/1.J051452
  4. Barth, T., Scholz, P. and Wierach, P. (2011), "Flow control by dynamic vane vortex generators based on piezoceramic actuators", AIAA J, 49( 5), 921-931. https://doi.org/10.2514/1.J050378
  5. Gardner, A.D., Richter K., Mai, H. and Neuhaus, D. (2012), "Experimental control of compressible OA209 dynamic stall by air jets", 38th ERF, Amsterdam, Sept.
  6. Weaver, D., McAlister, K.W. and Tso, J. (2004), "Control of VR7 dynamic stall by strong steady blowing", J. Aircraft, 41(6), 1404-1413. https://doi.org/10.2514/1.4413
  7. Kaufmann, K., Gardner, A.D. and Richter, K. (2012), "Numerical investigations of a back-flow flap for dynamic stall control", STAB 2012, Stuttgart, Germany, Nov.
  8. Meyer, R.K.J. (2000), "Experimentelle untersuchungen von ruckstromklappen auf tragflugeln zur beeinflussung von stromungsablosungen", Mensch-und-buch-verlag, Dissertation technische universitat Berlin.
  9. Hofinger, M. (2012), "Rotorblatt mit integrierter passiver oberflachenklappe", Deutsches patent DE 10 2010 041 111 A1, Mar.
  10. Carr, L.W., Chandrasekhara, M.S., Wilder, M.C. and Noonan, K.W. (2001), "Effect of compressibility on suppression of dynamic stall using a slotted airfoil", J. Aircraft, 38(2), 296-309. https://doi.org/10.2514/2.2762
  11. Martin, P.B., McAlister, K.W., Chandrasekhara, M.S. and Geissler, W. (2003), "Dynamic stall measurements and computations for a VR-12 airfoil with a variable droop leading edge", American helicopter society 59th annual forum, Phoenix, Arizona, May.
  12. Friedmann, P.P., de Terlizzi, M. and Myrtle, T.F. (2001), "New developments in vibration reduction with actively controlled trailing edge flaps", Math. Comput. Model., 33(10-11), 1055-1083. https://doi.org/10.1016/S0895-7177(00)00300-9
  13. Ahci-Ezgi, E., Denecke, U., Kuntze-Fechner., Mueller, C. and Pfaller, R. (2013), "Piezo active rotor blade: challenges and solutions", American helicopter society 69th annual forum, Phoenix, Arizona, May.
  14. Gallot, J., Vingut, G., De Paul, M.V. and Thibert, J. (1982), "Blade profile for rotary wing of an aircraft", United states patent 4325675, (20.4.1982).
  15. Mulleners, K. and Raffel, M. (2012), "The onset of dynamic stall revisited", Exp. Fluids, 52(3), 779-793, DOI 10.1007/s00348-011-1118-y. https://doi.org/10.1007/s00348-011-1118-y
  16. Gardner, A.D., Richter, K. and Rosemann, H. (2012), "Numerical investigation of air jets for dynamic stall control on the OA209 airfoil", CEAS Aeronaut. J, 1(1), 69-82, DOI 10.1007/s13272-011-0002-z. https://doi.org/10.1007/s13272-011-0002-z
  17. Richter, K., Le Pape, A., Knopp, T., Costes, M., Gleize, V. and Gardner, A.D. (2011), "Improved two-dimensional dynamic stall prediction with structured and hybrid numerical methods", J. Am. Helicopter Soc., 56(4), 1-12, DOI 10.4050/JAHS.56.042007. https://doi.org/10.4050/JAHS.56.042007
  18. Wierach, P. (2012a), "Nano-micro-macro", Adaptive, tolerant and efficient composite structures, Research in Aerospace, Wiedemann,M. and Sinapius,M. (eds), Springer-verlag berlin heidelberg 2012, DOI 10.1007/978-3-642-29190-6_2, pp. 17-28.
  19. Wierach, P., Riemenschneider, J., Opitz, S. and Hoffmann, F. (2012b), "Experimental investigation of an active twist model rotor blade under centrifugal loads", Adaptive, tolerant and efficient composite structures, Research in Aerospace, Wiedemann,M. and Sinapius,M. (eds), Springer-Verlag Berlin Heidelberg 2012, DOI 10.1007/978-3-642-29190-6_32, pp. 391-407.
  20. Grote, K.H. and Feldhusen, J. (2012), "Dubbel: taschenbuch fur den Maschinenbau", 23rd edition, Springer-Verlag Berlin Heidelberg 2012.
  21. Opitz, S., Riemenschneider, J., Hoffmann, F. and Schneider, O. (2010), "Measurement of the dynamic tip twist angles of an active twist model scale rotor blade", 36th European Rotorcraft Forum, Paris, France, Sept.
  22. Wierach, P., Riemenschneider, J., Opitz, S. and Hoffmann, F. (2012c), "Experimental investigation of an active twist model rotor blade under centrifugal loads", Adaptive, tolerant and efficient composite structures, Research in Aerospace, Wiedemann,M. and Sinapius,M. (eds), Springer-verlag berlin heidelberg 2012, ISBN 978-3-642-29189-0.(2012), 391-407.
  23. Wierach, P. (2012d), "Piezocomposite transducers for adaptive structures", Adaptive, tolerant and efficient composite structures, Research in Aerospace, Wiedemann, M. and Sinapius, M. (eds), Springer-Verlag Berlin Heidelberg 2012, DOI 10.1007/978-3-642-29190-6_3, pp. 29-47.
  24. Wierach, P. (2006), "Low profile piezo actuators based on multilayer technology", Conference proceedings. 17.international conference on adaptive systems and structures, Taipei, Taiwan, Oct.
  25. Algermissen, S., Keimer, R., Rose, M., Straubel, M., Sinapius, M. and Monner, H.P. (2011), "Smart-structures technology for parallel robots", J. Intelligent Robot Syst., 63, 547-574, DOI 10.1007/s10846-010-9522-8. ISSN 0921-0296. https://doi.org/10.1007/s10846-010-9522-8

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