Numerical investigation of tangential blowing over the rudder of a vertical tailplane


Tangential blowing over the shoulder of a deflected rudder is applied on a vertical tailplane. For a large rudder deflection angle and without blowing the flow is mostly separated on the rudder. Three configurations are investigated in a numerical study with the aim to increase the side force coefficient. The first one is the baseline without blowing, the second one has a continuous full span slot and for the third one discrete slots are used. With sufficient blowing through the continuous slot the separation on the rudder can be removed completely while the separation extent is greatly reduced when using discrete slots. This is investigated for different sideslip angles. An approximately linear increase in the side force coefficient can be found until a sudden side force breakdown occurs. In a further study, the jet blowing velocity is varied. A smaller jet velocity leads to a smaller increase in the side force coefficient. Comparing the continuous and discrete slot configurations shows that for a similar increase in the side force coefficient a much smaller mass flow rate is needed for the discrete slots. However, for jet velocities below the sonic speed the increase in the side force coefficient is limited. It can only be increased by a larger slot extent in spanwise direction but this comes at the expense of an increase in the required mass flow rate.

This is a preview of subscription content, access via your institution.

Fig. 1
Fig. 2
Fig. 3
Fig. 4
Fig. 5
Fig. 6
Fig. 7
Fig. 8
Fig. 9
Fig. 10
Fig. 11
Fig. 12
Fig. 13
Fig. 14
Fig. 15
Fig. 16
Fig. 17
Fig. 18
Fig. 19
Fig. 20
Fig. 21
Fig. 22
Fig. 23
Fig. 24
Fig. 25
Fig. 26
Fig. 27


  1. 1.

    Pfingsten, K.C., Radespiel, R.: Experimental and numerical investigation of a circulation control airfoil. In: AIAA Paper 2009-533 (2009)

  2. 2.

    Andino, M.Y., Lin, J.C., Washburn, A.E., Whalen, E.A., Graff, E.C., Wygnanski, I.J.: Flow separation control on a full-scale vertical tail model using sweeping jet actuators. AIAA Paper 2015-0785 (2015)

  3. 3.

    Seifert, A., Tilmann, C.P.: Control of flow separation for fixed wing airfoil applications. In: Bonnet, J.-P., Anthoine, J. (eds.) Flow Control: Fundamentals, Advances and Applications. Von Karman Institute for Fluid Dynamics Lecture Series 2009–02, Rhode Saint Genese, Belgium (2009)

  4. 4.

    Burnazzi, M., Radespiel, R.: Design of a droopnose configuration for a coanda active flap application. AIAA Paper 2013-0487 (2013)

  5. 5.

    Beck, N., Radespiel, R., Lenfers, C., Friedrichs, J., Rezaeian, A.: Aerodynamic effects of propeller slipstream on a wing with circulation control. J. Aircr. 52(5), 1422 (2015)

    Article  Google Scholar 

  6. 6.

    Rathay, N.W., Boucher, M.J., Amitay, M., Whalen, E.: Performance enhancement of a vertical stabilizer using synthetic jet actuators: no sideslip. In: AIAA Paper 2012-0071 (2012)

  7. 7.

    Rathay, N.W., Boucher, M.J., Amitay, M., Whalen, E.: Performance enhancement of a vertical stabilizer using synthetic jet actuators: non-zero sideslip. In: AIAA Paper 2012-2657 (2012)

  8. 8.

    Seele, R., Graft, E., Gharib, M.: Improving rudder effectiveness with sweeping jet actuators. In: AIAA Paper 2012-3244 (2012)

  9. 9.

    Lin, J.C., Andino, M.Y., Alexander, M.G., Whalen, E.A., Spoor, M.A., Tran, J.T., Wygnanski, I.J.: An overview of active flow control enhanced vertical tail technology development. In: AIAA Paper 2016-0056 (2016)

  10. 10.

    Scholz, P., Singh, V.M., Gebhardt, A., Löffler, S., Weiss, J.: A comparison of different active flow control methods on a generic vertical tail, Deutscher Luft- und Raumfahrtkongress 2018, Friedrichshaven, Germany, 2018

  11. 11.

    Childs, R.E., Stremel, P.M., Garcia, J.A., Heineck, J.T., Kushner, L.K., Stormsk, B.L.: Simulation of sweep-jet flow control, single jet and full vertical tail. In: AIAA Paper 2016-0569 (2016)

  12. 12.

    Englar, R.J.: Circulation control for high lift and drag generation on STOL aircraft. J. Airc. 12(5), 457 (1975)

    Article  Google Scholar 

  13. 13.

    Gebhardt, A., Kirz, J.: Numerical investigation of slot variations on the efficiency of tangential blowing at a vertical tailplane with infinite span. CEAS Aeronaut. J. (2018).

    Article  Google Scholar 

  14. 14.

    Kröhnert, A.: Numerical investigation of tangential blowing at the rudder of a vertical tailplane airfoil. In: AIAA Paper 2014-2143 (2014)

  15. 15.

    Ciobaca, V.: Validation of numerical simulations for separation control on high-lift configurations. Ph.D. thesis, DLR (German Aerospace Center), (2014)

  16. 16.

    CentaurSoft: Centaur hybrid grid generation system, [online web site], URL:, [cited 20th June 2019]

  17. 17.

    Gerhold, T.: Overview of the hybrid RANS code TAU. In: Kroll, N., Fassbender, J. (eds.) Megaflow—Numerical Flow Simulation for Aircraft Design. Numerical Fluid Mechanics and, vol. 89, pp. 81–92. Springer, Berlin (2005)

    Google Scholar 

  18. 18.

    Spalart, P., Allmaras, S.: One-equation turbulence model for aerodynamic flows. In: AIAA Paper 92-0439 (1992)

  19. 19.

    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(5), 784–792 (2000)

    Article  Google Scholar 

  20. 20.

    Pfingsten, K.-C., Jensch, C., Körber, K.W., Radespiel, R.: Numerical simulation of the flow around circulation control airfoils. In: CEAS 2007-377 (2007)

  21. 21.

    Küchemann, D.: A simple method for calculating the span and chordwise loading on straight and swept wings of any given aspect ratio at subsonic speeds. R & M No. 2935, A.R.C. Technical Report, (1956)

Download references


This work is part of the collaborative research project AsSaM (Autoritätssteigerung von Steuerflächen durch aktive Maßnahmen), funded by the German Bundesministerium für Wirtschaft und Energie (Federal Ministry for Economic Affairs and Energy) (Grant no. 20E1513C), which is gratefully acknowledged.

Author information



Corresponding author

Correspondence to A. Gebhardt.

Additional information

Publisher's Note

Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Rights and permissions

Reprints and Permissions

About this article

Verify currency and authenticity via CrossMark

Cite this article

Gebhardt, A. Numerical investigation of tangential blowing over the rudder of a vertical tailplane. CEAS Aeronaut J 11, 487–499 (2020).

Download citation


  • Vertical tail
  • VTP
  • Active flow control
  • CFD
  • Tangential blowing
  • Discrete slots