Investigation and improvement of directional stability and control of a propeller-driven STOL aircraft

  • Dennis KellerEmail author
  • Ralf Rudnik
Original Paper


The scope of this paper is to investigate and improve the aerodynamic properties of a propeller driven state-of-the-art active high-lift configuration in lateral motion. 3D RANS simulations of the landing configuration with circulation control and slipstream deflection under crosswind, and one engine inoperative (OEI) conditions were performed. The configuration shows directionally unstable behavior at small sideslip angles and high yawing moment production under OEI conditions. Flowfield analyses indicate that both can be attributed to wake-tail interference effects caused by slipstream–vortex interaction. The integration of tail fences at the rear of the fuselage leads to considerable improvements for both conditions.

List of symbols

Roman symbols


Wing span, m

\(c_\mathrm {ref}\)

Mean aerodynamic chord length (main wing), m


Jet momentum coefficient \(\frac{{\rho _{\mathrm{jet}}}{V_{\mathrm{jet}}^2} {S_\text {slot}}}{{q_ {\infty }{S_{\mathrm{ref}}}}}\)


Aircraft drag coefficient \(\frac{D}{q_{\infty }S_\mathrm {ref}}\)


Aircraft lift coefficient \(\frac{L}{q_{\infty }S_\mathrm {ref}}\)


Aircraft rolling moment coefficient \(\frac{2Mx}{q_{\infty }S_\mathrm {ref}b}\)


Aircraft pitching moment coefficient \(\frac{My}{q_{\infty }S_\mathrm {ref}c_\mathrm {ref}}\)


Aircraft yawing moment coefficient \(\frac{2Mz}{q_{\infty }S_\mathrm {ref}b}\)


Pressure coefficient \(\frac{p-p_\infty}{q_\infty}\)


Thrust coefficient \(\frac{T}{\rho n^2 D^4}\)


Mach number


Dynamic pressure \(\frac{\rho V^{2}}{2}\), Pa

\(r_\mathrm {HTP}\)

HTP arm (\(25\%\) MAC), m

\(r_\mathrm {VTP}\)

VTP arm (\(25\%\) MAC), m




x-wise velocity component


y-wise velocity component

\(V_{\infty }\)

Reference velocity, m / s

\(V_\mathrm {HTP}\)

Relative tail volume (HTP) \(\frac{S_\mathrm {HTP} r_\mathrm {HTP}}{S_\mathrm {ref} ~ c_\mathrm {ref}}\), m

\(V_\mathrm {VTP}\)

Relative tail volume (VTP) \(\frac{2S_\mathrm {VTP} r_\mathrm {VTP}}{S_\mathrm {ref} ~ b}\), m


z-wise velocity component


Roll axis


Pitch axis


Yaw axis

Greek symbols


Angle of attack, deg


Sideslip angle, deg

\(\delta _\mathrm {Flap}\)

Flap deflection, deg


Dimensionless half span \(\frac{2Y}{b}\)


Glide slope, deg


Dimensionless length \(\frac{(X-13.131m)}{c_\mathrm {ref}}\)


Dimensionless height \(\frac{Z}{h}\)



Center of gravity


Horizontal tail plane


Maximum landing weight


One engine inoperative


Vertical tail plane



Financial support has been provided by the German Research Foundation (Deutsche Foschungsgemeinschaft – DFG) in the framework of the Collaborative Research Center 880.


  1. 1.
    Fink, M.P., Cocke, B.W., Lipson, S.: A Wind-Tunnel Investigation of a 0.4-Scale Model of an Assault Transport Airplane With Boundary-Layer Control Applied. Research Memorandum L55G26a, NACA, (1956)Google Scholar
  2. 2.
    Weiberg, J.A., Griffin Jr., R.N., Florman, G.L.: Large-Scale Wind-Tunnel Tests of an Airplane Model with an Unswept, Aspect-Ratio-10 Wing, Two Propellers, and Area-Suction Flaps. Technical Note 4365, NASA, (1958)Google Scholar
  3. 3.
    Griffin Jr., R.N., Holzhauser, C.A.: Large-scale wind-tunnel tests of an airplane model with an unswept, aspect-ratio-10 wing, two propellers, and blowing flaps. Memorandum, NASA (1958)Google Scholar
  4. 4.
    Weiberg, J.A., Page, V.R.: Large-Scale Wind-Tunnel Tests of an Airplane Model with an Unswept, Aspect-Ratio-10 Wing, Four Propellers, and Blowing Flaps. Technical Note D-25, NASA, (1959)Google Scholar
  5. 5.
    Weiberg, J.A., Holzhauser, C.A.: STOL characteristics of a propeller-driven, aspect-ratio-10 wing, straight-wing airplane with boundary-layer control flaps, as estimated from large-scale wind-tunnel tests. Technical Note D-1032, NASA, (1961)Google Scholar
  6. 6.
    Petrov, A.V.: Aerodynamics of stol airplanes with powered high-lift systems. In: Proceedings of the ICAS 2012 CongressPaper, Brisbane, Australia, September 2012.Google Scholar
  7. 7.
    Quigley, H.C., Innis, R.C.: Handling qualities and operational problems of a large four-propeller stol transport airplane. NASA Technical Note D-1647, Ames Research Center, Moffett Field, Ca, Januar (1963)Google Scholar
  8. 8.
    Pitkin, M., Draper, J.W., Bennett, C.V.: The Influence of Vertical-tail Design and Direction of Propeller Rotation on Trim Characteristics of a Twin-engine-airplane Model with One Engine Inoperative. Advance Restricted Report NACA-ARR-L5A13, NACA, (1945)Google Scholar
  9. 9.
    Mannée, J.: Windtunnel Investigation of the Influence of the Aircraft Configuration on the Yawing and Rolling Moments of a Twin-Engined Propeller Driven Aircraft with one Engine Inoperative. Technical report, Amsterdam (1962)Google Scholar
  10. 10.
    Schroijen, M.J.T., Veldhuis, L.L.M., Slingerland, R.: Propeller empennage interaction effects on vertical tail design of multiengine aircraft. J. Aircr. 47, 1133–1140 (2010)CrossRefGoogle Scholar
  11. 11.
    Pitkin, M.: Free-Flight-tunnel Investigation of the Effect of Mode of Propeller Rotation Upon the Lateral-stability Characteristics of a Twin-engine Airplane Model with Single Vertical Tails of Different Size. Advance Restricted Report NACA-ARR-3J18, NACA, (1943)Google Scholar
  12. 12.
    Stüper, J.: Effect of Propeller Slipstream on Wing and Tail. Technical Memorandum NACA-TM-0874, NACA, (1938)Google Scholar
  13. 13.
    Sweberg, H. H.: The Effect of Propeller Operation on the Air Flow in the Region of the Tail Plane for a Twin-engine Tractor Monoplane. Advance Restricted Report NACA-ARR-L381, NACA, (1942)Google Scholar
  14. 14.
    Rogallo, F.M., Swanson, R.S.: Wind-tunnel Tests of a Twin-engine Model to Determine the Effect of Direction of Propeller Rotation on the Static-stability Characteristics. Advance Restricted Report NACA-ARR-L295, NACA, (1942)Google Scholar
  15. 15.
    Johnson, H.: Flight Investigation of the Effect of Various Vertical-Tail Modifications on the Directional Stability and Control Characteristics of a Propeller-Driven Fighter Airplane. Technical Report NACA-TR-973, NACA, (1950)Google Scholar
  16. 16.
    Spearman, M.L., Henderson, Jr. A.: Some Effects of Aircraft Configuration on Static Longitudinal and Directional Stability Characteristics at Supersonic Mach Numbers below 3. Research Memorandum NACA-RM-L55L15a, NACA, (1956)Google Scholar
  17. 17.
    Kiyoshi, A., Falarski, M.D., Koenig, D.G.: Wind Tunnel Investigation of a Large-Scale Upper Surface Blown-Flap Transport Model having Two Engines. Technical Memorandum NASA-TM-X-62296, NASA, (1973)Google Scholar
  18. 18.
    Keller, D., Rudnik, R.: Numerical investigations of aerodynamic properties of a propeller blown circulation control system on a high wing aircraft. CEAS Aeronaut. J. 7(3), 441–454 (2016)CrossRefGoogle Scholar
  19. 19.
    Gerhold, T.: Overview of the Hybrid RANS Code TAU. In MEGAFLOW – Numerical Flow Simulation for Aircraft Design, volume 89 of Notes on Numerical Fluid Mechanics and Multidisciplinary Design, pages 81–92. Springer, New York (2005)Google Scholar
  20. 20.
    Spalart, P.R., Allmaras, S.R.: A One–Equation Turbulence Model for Aerodynamic–Flows. AIAA Paper 92–439, (1992)Google Scholar
  21. 21.
    Spalart, P.R., Shur, M.: On the sensitization of turbulence models to rotation and curvature. Aerosp. Sci. Technol. 1, 297–302 (1997)CrossRefzbMATHGoogle Scholar
  22. 22.
    Pfingsten, K.C., Jensch, C., Körber, K.W., Radespiel, R.: Numerical Simulation of the Flow Around Circulation Control Airfoils. In first CEAS European air and space conference, Berlin, Germany, (2007)Google Scholar
  23. 23.
    Pfingsten, K.C., Radespiel, R.: Experimental and Numerical Investigation of a Circulation Control Airfoil. In 47th AIAA Aerospace Sciences Meeting, number AIAA-2009-0533, Orlando,Florida, (2009)Google Scholar
  24. 24.
    Churchfield, Matthew J., Blaisdell, Gregory A.: Numerical Simulations of a Wingtip Vortex in the Near Field. J. Aircr. 46(1), 230–243 (2009)CrossRefGoogle Scholar
  25. 25.
    Raichle, A., Melber-Wilkending, S., Himisch, J.: A new Actuator Disk Model for the TAU Code and application to a sailplane with a folding engine. In: New results in numerical and experimental fluid mechanics VI: contributions to the 15th STAB/DGLR symposium Darmstadt, Germany, volume 96. Springer Berlin Heidelberg, (2008)Google Scholar
  26. 26.
    Gutierrez, C., Marquez, O.: Validation of Actuator Disk Simulations of CROR Propulsion Systems at Low-Speed Flight Conditions. New Orleans, USA, 2012. American Institute of Aeronautics and AstronauticsGoogle Scholar
  27. 27.
    Lenfers, C., Beck, Nils, Bauer, Marc: Propeller and active high lift wing interaction in experiment and simulation. New Results Numer Exp Fluid Mech X 132, 51–61 (2016)CrossRefGoogle Scholar
  28. 28.
    Heinze, W., Österheld, C.M., Horst, P.: Multidisziplinäres Flugzeugentwurfsverfahren PrADO - Programmentwurf und Anwendung im Rahmen von Flugzeug-Konzeptstudien. In Deutsche Gesellschaft für Luft-und Raumfahrt (DGLR), editor, DGLR-Jahrbuch 2001, volume 3, pages 1701–1712. Bonn, (2001)Google Scholar
  29. 29.
    Weiss, T.W., Heinze, W.: Multidisciplinary Design of CESTOL Aircraft with Powered Lift System. In: Rolf Radespiel and Richard Semaan, editors, TU Braunschweig - Campus Forschungsflughafen, Berichte aus der Luft- und Raumfahrttechnik, number 2013-3. Shaker Verlag, (2013)Google Scholar
  30. 30.
    Kühn, T., Wild, J.: Aerodynamic Optimization of a Two-Dimensional Two-Element High Lift Airfoil with a Smart Droop Nose Device. Number 2005-89, Paris, France, 2010. 1st EASN Association Workshop on AerostructuresGoogle Scholar
  31. 31.
    Burnazzi, M., Radespiel, R.: Design of a Droopnose Configuration for a Coanda Active Flap Application. Grapevine, Texas, USA, 2013. 51st AIAA Aerospace Sciences Meeting including the New Horizons Forum and Aerospace ExpositionGoogle Scholar
  32. 32.
    Keller, D.: Numerical Approach Aspects for the Investigation of the Longitudinal Static Stability of a Transport Aircraft with Circulation Control. In: New Results in Numerical and Experimental Fluid Mechanics IX, volume 124 of Notes on Numerical Fluid Mechanics and Multidisciplinary Design, pp. 13–22. Springer, New York (2014)Google Scholar
  33. 33.
    CentaurSoft. Centaur hybrid grid generation system. In [online web site], URL: Accessed 19 Nov 2012
  34. 34.
    Keller, D., Rudnik, R.: Numerical investigation of engine effects on a transport aircraft with circulation control. J. Aircr. 52(2), 421–438 (2015)CrossRefGoogle Scholar
  35. 35.
    Schlichting, H., Truckenbrodt, E.A.: Aerodynamik des Flugzeuges. Zweiter Band. Springer-Verlag, Berlin Heidelberg (1969)CrossRefzbMATHGoogle Scholar

Copyright information

© Deutsches Zentrum für Luft- und Raumfahrt e.V. 2019

Authors and Affiliations

  1. 1.Transport Aircraft DepartmentInstitute of Aerodynamics and Flow Technology, German Aerospace CenterBraunschweigGermany

Personalised recommendations