Skip to main content
SpringerLink
Log in

Semi-empirical modeling of fuselage–rotor interference for comprehensive codes: influence of angle of attack

  • Original Paper
  • Published:
CEAS Aeronautical Journal Aims and scope Submit manuscript

Abstract

The flow field around the isolated Bo105 fuselage including the tail boom and empennage is computed by an unsteady panel code. Velocities normal to the rotor rotational plane are extracted in a volume around the rotor as a data base. A simple semi-empirical analytical formulation of the fuselage-induced velocities, based on parameter estimation from the panel code data, is extended to include rotor shaft angles of attack from \(\alpha =-90^{\circ }\) (hover, vertical climb) to +90° (vertical descent) for use in comprehensive rotor codes. This model allows the computation of fuselage–rotor interferences on the rotor blade element level in a simplified form, thus eliminating the need for costly CFD computation (of this effect). It also allows the prediction of the rotor wake geometry deformation due to the presence of the fuselage in both prescribed wake and free-wake codes. Its impact on rotor thrust, power and trim is estimated analytically using blade element momentum theory.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Log in via an institution

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Institutional subscriptions

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

Similar content being viewed by others

Abbreviations

A, B :

Non-dimensional radial effective begin and end of airfoiled section

\(A_0\) :

Non-dimensional magnitude of fuselage-induced flow

c :

Rotor blade chord (m)

\(C_{l\alpha }\) :

Lift curve slope (1/rad)

\(c_{kn}\) :

Polynomial coefficient

\(C_T\) :

Thrust coefficient, \(C_T=T/[\rho \pi R^2(\Omega R)^2]\)

\(C_W\) :

Weight coefficient, \(C_W=W/[\rho \pi R^2(\Omega R)^2]\)

\(\mathrm{d}(n)\) :

Radial integral coefficient, \(\mathrm{d}(n)=\int _A^Br^{n-1}\mathrm{d}r=(B^n-A^n)/n\)

M :

Mach number

\(M_\beta\) :

Aerodynamic moment about flap hinge (Nm)

\(N_b\) :

Number of blades

r :

Non-dimensional radial coordinate

R :

Rotor radius (m)

\(S_A, S_x, S_y\) :

Shape functions of amplitude, in x- and in y-direction

T :

Rotor thrust (N)

\(v_{izf}\) :

Fuselage-induced velocity normal to the hub plane, pos. downwards (m/s)

\(v_{i0}\) :

Thrust-induced velocity, pos. downwards (m/s)

\(V_T\) :

Tangential velocity at the blade element in the hub plane (m/s)

\(V_P\) :

Velocity at the blade element perpendicular to the hub plane (m/s)

\(V_\infty\) :

Airspeed (m/s)

W :

Helicopter weight (N)

x, y, z :

Hub-fixed coordinates (m)

\(x_0, y_0, z_0\) :

Position of maximum induced velocities (m)

\(\alpha , \alpha _a\) :

Shaft and blade element angle of attack (°)

\(\beta\) :

Side-slip angle (°)

\(\Theta\) :

Blade element pitch angle (°)

\(\Theta _C, \Theta _S\) :

Lateral and longitudinal cyclic control angle (°)

\(\lambda _{if}\) :

Fuselage-induced inflow ratio, \(\lambda _{if}=v_{izf}/V_\infty\)

\(\lambda _{i0}\) :

Thrust-induced inflow ratio, \(\lambda _{i0}=v_{i0}/(\Omega R)\)

\(\mu\) :

Advance ratio, \(\mu =V_\infty \cos \alpha /(\Omega R)\)

\(\mu _z\) :

Axial advance ratio, \(\mu _z=-V_\infty \sin \alpha /(\Omega R)=-\mu \tan \alpha\)

\(\rho\) :

Air density (kg/m\(^3\))

\(\sigma\) :

Rotor solidity (rectangular blade), \(\sigma =N_bc/(\pi R)\)

\(\psi\) :

Rotor blade azimuth (°)

\(\Omega\) :

Rotor rotational frequency (rad/s)

References

  1. Sheridan, P.F., Smith, R.P.: Interactional aerodynamics: a new challenge to helicopter technology. J. Am. Helicopter Soc. 25(1), 3–21 (1980)

    Google Scholar 

  2. Huber, H., Polz, G.: Studies on blade-to-blade and rotor–fuselage–tail interferences. Aircr. Eng. Aerosp. Technol. 55(10), 2–12 (1983)

    Article  Google Scholar 

  3. Keys, C., Wiesner, R.: Guidelines for reducing helicopter parasite drag. J. Am. Helicopter Soc. 20(1), 31–40 (1975)

    Article  Google Scholar 

  4. Stepniewski, W.Z., Keys, C.N.: Rotary-wing aerodynamics. ISBN 0-486-64647-5, Dover Publications (1984)

  5. Leishman, J.G.: Principles of helicopter aerodynamics. ISBN 0-521-66060-2, Cambridge University Press (2001)

  6. Dreier, M.E.: Introduction to helicopter and tiltrotor flight simulation. ISBN-13: 978-1-56347-873-4, AIAA Education Series, Reston, VA (2007)

  7. van der Wall, B.G., Bauknecht, A., Jung, S.N., You, Y.H.: Semi-empirical modeling of fuselage-rotor interference for comprehensive codes: the fundamental model. CEAS Aeronaut. J. 5(4), 387–401 (2014)

    Article  Google Scholar 

  8. van der Wall, B.G.: A comprehensive rotary-wing database for code validation: the HART II International Workshop. Aeronaut. J. R. Aeronaut. Soc. 115(1163), 91–102; erratum: 115(1166), 220 (2011)

  9. Clark, D.R., Maskew, B.: Calculation of unsteady rotor blade loads and blade/fuselage interference. In: 2nd International conference on rotorcraft basic research, College Park, MD, 16–18 Feb 1988

  10. Clark, D.R., Maskew, B.: A re-examination of the aerodynamics of hovering rotors including the presence of the fuselage. In: International technical specialists’ meeting on rotorcraft basic research, Atlanta, Georgia, 25–27 March 1991; also in: 47th Annual Forum of the American Helicopter Society, Phoenix, AZ, 6–8 May 1991

  11. Wachspress, D.A., Quackenbush, T.R., Boschitsch, A.H.: Rotorcraft interactional aerodynamics with fast vortex/fast panel methods. J. Am. Helicopter Soc. 48(4), 223–235 (2003)

    Article  Google Scholar 

  12. Brown, R.E., Line, A.J., Ahlin, G.A.: Fuselage and tail-rotor interference effects on helicopter wake development in descending flight. In: 60th American Helicopter Society Annual Forum, Baltimore, MD, 7–10 June 2004

  13. Brown, R.E., Line, A.J.: Efficient high-resolution wake modeling using the vorticity transport equation. AIAA J. 43(7), 1434–1443 (2005)

    Article  Google Scholar 

  14. Kim, H.W., Kenyon, A.K., Duraisamy, K., Brown, R.E.: Interactional aerodynamics and acoustics of a propeller-augmented compound coaxial helicopter. In: American Helicopter Society Specialists’ Conference on Aeromechanics, San Francisco, CA, 23–25 Jan 2008

  15. D’Andrea, A.: Development of a multi-processor unstructured panel code coupled with a CVC free wake model for advanced analyses of rotorcrafts and tiltrotors. In: 64th Annual Forum of the American Helicopter Society, Montreal, Canada, 29 April–1 May 2008

  16. Keller, J.D., Wachspress, D.A., Hoffler, J.C., Kachman, N.J., Nichols, J.: Application of a real time free wake induced velocity model in a Naval rotorcraft flight trainer. In: 67th Annual Forum of the American Helicopter Society, Virginia Beach, VA, 3–5 May 2011

  17. Quon, E.W., Smith, M.J., Whitehouse, G.R., Wachspress, D.A.: Unsteady reynolds-averaged Navier–Stokes-based hybrid methodologies for rotor–fuselage interaction. J. Aircr. 49(3), 961–965 (2012)

    Article  Google Scholar 

  18. Yin, J.: Main rotor and tail rotor blade–vortex interaction noise under the influence of the fuselage. In: 38th European Rotorcraft Forum. Amsterdam, The Netherlands 4–7 Sept 2012

  19. Yin, J., van der Wall, B.G., Oerlemans, S.: Representative test results from HELINOVI aeroacoustic main rotor/tail rotor/fuselage test in DNW. In: 31st European Rotorcraft Forum. Florence, Italy 13–15 Sept 2005

  20. Jacob, H.G.: Rechnergestntzte optimierung statischer und dynamischer Systeme. Fachberichte Messen, Steuern, Regeln, Band 6; ISBN 3-540-11641-9, Springer Verlag (1982)

Download references

Author information

Authors and Affiliations

  1. German Aerospace Center (DLR), Institute of Flight Systems, Lilienthalplatz 7, 38108, Braunschweig, Germany

    Berend G. van der Wall

  2. German Aerospace Center (DLR), Institute of Aerodynamics and Flow Technology, Lilienthalplatz 7, 38108, Braunschweig, Germany

    Jianping Yin

Authors
  1. Berend G. van der Wall
    View author publications

    You can also search for this author in PubMed Google Scholar

  2. Jianping Yin
    View author publications

    You can also search for this author in PubMed Google Scholar

Corresponding author

Correspondence to Berend G. van der Wall.

Rights and permissions

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

van der Wall, B.G., Yin, J. Semi-empirical modeling of fuselage–rotor interference for comprehensive codes: influence of angle of attack. CEAS Aeronaut J 6, 557–574 (2015). https://doi.org/10.1007/s13272-015-0163-2

Download citation

  • Received:

  • Revised:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1007/s13272-015-0163-2

Keywords

Search

Navigation