Skip to main content

Advertisement

SpringerLink
Log in

A comprehensive PIV measurement campaign on a fully equipped helicopter model

  • Research Article
  • Published:
Experiments in Fluids Aims and scope Submit manuscript

Abstract

The flow field around a helicopter is characterised by its inherent complexity including effects of fluid–structure interference, shock–boundary layer interaction, and dynamic stall. Since the advancement of computational fluid dynamics and computing capabilities has led to an increasing demand for experimental validation data, a comprehensive wind tunnel test campaign of a fully equipped and motorised generic medium transport helicopter was conducted in the framework of the GOAHEAD project. Different model configurations (with or without main/tail rotor blades) and several flight conditions were investigated. In this paper, the results of the three-component velocity field measurements around the model are surveyed. The effect of the interaction between the main rotor wake and the fuselage for cruise/tail shake flight conditions was analysed based on the flow characteristics downstream from the rotor hub and the rear fuselage hatch. The results indicated a sensible increment of the intensity of the vortex shedding from the lower part of the fuselage and a strong interaction between the blade vortex filaments and the wakes shed by the rotor hub and by the engine exhaust areas. The pitch-up phenomenon was addressed, detecting the blade tip vortices impacting on the horizontal tail plane. For high-speed forward flight, the shock wave formation on the advancing blade was detected, measuring the location on the blade chord and the intensity. Furthermore, dynamic stall on the retreating main rotor blade in high-speed forward flight was observed at r/R = 0.5 and 0.6. The analysis of the substructures forming the dynamic stall vortex revealed an unexpected spatial concentration suggesting a rotational stabilisation of large-scale structures on the blade.

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
Fig. 16

Similar content being viewed by others

Abbreviations

CFD:

Computational fluid mechanics

DEHS:

Di-ethyl-hexyl-sebacat

DS:

Dynamic stall

GOAHEAD:

Generation of advanced helicopter experimental aerodynamic database for CFD code validation

PIV:

Particle image velocimetry

WT:

Wind tunnel

a :

Speed of sound, m/s

c :

Blade chord, m

L :

Fuselage length, m

L m :

Measurement volume length, m

M :

Mach number

r :

Radial coordinate, m

r v :

Vortex radius, m

r c :

Vortex core radius, m

R :

Rotor radius, m

t :

Time, s

u, v, w :

Velocity components, m/s

V :

Velocity, m/s

V r, V θ :

Radial and tangential velocity, m/s

x, y, z :

Coordinates, m

α:

Fuselage incidence angle, deg

ε:

Measurement error

Γ:

Circulation, m2/s

λ2 :

Flow field operators, (rad/s)2

μ:

Advance ratio, V/(Ω R)

ν:

Kinematic viscosity, m2/s

ρ:

Air density, kg/m3

σ:

Standard deviation

Ψ:

Azimuth, Ω t, deg

ω:

Vorticity, rad/s

Ω:

Rotor rotational frequency, rad/s

b :

Blade

MR:

Main rotor

TR:

Tail rotor

WT:

Wind tunnel

s :

Shaft

u :

Velocity

x :

Displacement

References

  • Althoff Gorton S, Berry JD, Hodge WT, Reis DG (2002) Rotor Wake Study Near the Horizontal Tail of a T-Tail Configuration. J Aircr 39(4):645–653

    Google Scholar 

  • Barbagallo D, De Gregorio F, Tino N (2000) Pitch-up phenomenon characterisation by means of HW and PIV measurements techniques. In: Proceedings of the 26th European rotorcraft forum, The Hague, NL

  • Benoit B, Dequin AM, Kampa K, von Grünhagen W, Basset PM, Gimonet B (2000) HOST, a general helicopter simulation tool for Germany and France. In: Proceedings of the American helicopter society 56th annual forum, Virginia Beach, VA, USA

  • de Waard PG, Trouvé M (1999) Tail shake vibration. In: Proceedings of the 55th American helicopter society, Montreal, Canada

  • DiOttavio J, Watson K, Cormey J, Komerath N (2008) Discrete structures in the radial flow over a rotor blade in dynamic stall. In: Proceedings of the 26th applied aerodynamics conference, AIAA, Honolulu, Hawaii, USA

  • Fletcher TM, Brown RE (2007) Main rotor—empennage interaction and its effects on helicopter flight dynamics. In: Proceedings of the American helicopter society 63rd annual forum, Virginia Beach, VA, USA

  • Graftieaux L, Michard M, Grosjean N (2001) Combining PIV, POD and vortex identification algorithms for the study of unsteady turbulent swirling flows. Meas Sci Technol 12:1422–1429

    Article  Google Scholar 

  • Heineck JT, Yamauchi GK, Wadcock AJ, Lourenco LM, Abrego AI (2000) Application of three-component PIV to a hovering rotor wake. In: Proceedings of the AHS 56th annual forum, Virginia Beach, VA, USA

  • Kindler K, Mulleners K, Richard H, van der Wall BG, Raffel M (2011) Aperiodicity in the near field of full-scale rotor blade tip vortices. Exp Fluids 50:1601–1610

    Article  Google Scholar 

  • Le Pape A, Gatard J, Monnier JC (2007) Experimental investigations of rotor–fuselage aerodynamic interaction. J Am Helicopter Soc 52:99

    Article  Google Scholar 

  • Lee TE, Leishmann GJ, Ramasamy M (2008) Fluid dynamics of interacting blade tip vortices with a ground plane. In: Proceedings of the 64th annual forum of the American helicopter society, Montreal, Canada

  • Leishman JG (2000) Principle of helicopter aerodynamics. Cambridge University Press, Cambridge

    Google Scholar 

  • Leishman JG, Bi NP (1994) Experimental investigation of rotor/lifting surface interactions. J Aircr 31(4):846–854. doi:10.2514/3.46570

    Google Scholar 

  • Martin PB, Pugliese GJ, Leishman JG, Anderson SL (2000) Stereo PIV measurement in the wake of a hovering rotor. In: Proceedings of the AHS 56th annual forum, Virginia Beach, VA, USA

  • Martin PB, Pugliese GJ, Leishman JG (2001) High resolution trailing vortex measurements in the wake of a hovering rotor. In: Proceedings of the AHS 57th annual forum, Washington, DC, USA

  • McCroskey W (1981) The phenomenon of dynamic stall. TM 81264, NASA

  • Mulleners K, Kindler K, Raffel M (2011) Dynamic stall on a fully equipped helicopter model. Aerosp Sci Technol (in press). doi:10.1016/j.ast.2011.03.013

  • Pahlke KG (2007) The GOAHEAD project. In: Proceedings of the 33rd European rotorcraft forum, Kazan, Russia

  • Raffel M, Seelhorst U, Willert C (1998) Vortical flow structures at a helicopter rotor model measured by LDV and PIV. Aeronaut J R Aeronaut Soc 102(1012):221–227

    Google Scholar 

  • Raffel M, Richard H, Ehrenfried K, Van der Wall B, Burley C, Beaumier P, McAlister K, Pengel K (2004) Recording and evaluation methods of PIV investigations on a helicopter rotor model. Exp Fluids 36:146–156

    Article  Google Scholar 

  • Raffel M, De Gregorio F, Sheng W, Gibertini G, Seraudie A, de Groot K, van der Wall BG (2009) Generation of an advanced helicopter experimental aerodynamic database. In: Proceedings of the 35th European rotorcraft forum, Hamburg, Germany

  • Raffel M, De Gregorio F, de Groot K, Schneider O, Sheng W, Gibertini G, Seraudie A (2011) On the generation of a helicopter aerodynamic database. Aeronaut J 115(1164):103–112

    Google Scholar 

  • Raghav V, Richards P, Komerath N, Smith M (2010) An exploration of the physics of dynamic stall. In: Proceedings of AHS aeromechanics specialists conference, AHS, San Francisco, CA, USA

  • Spentzos A, Barakos GN, Badcock KJ, Richards BE (2006) Modelling three-dimensional dynamic stall of helicopter blades using computational fluid dynamics and neural networks, Proceedings of the Institute of Mechanical Engineers, Part G. J Aeros Eng 220(6):605–618

    Google Scholar 

  • Van der Wall BG, Richard H (2006) Analysis methodology for 3C-PIV data of rotary wing vortices. Exp Fluids 40:798–812

    Article  Google Scholar 

  • Vollmers H (2001) Detection of vortices and quantitative evaluation of their main parameters from experimental velocity data. Meas Sci Technol 12:1199–1207

    Article  Google Scholar 

Download references

Acknowledgments

This project was funded by the European Union within the 6th Framework European Research Programme, contract Nr. 516074. The professional and personal commitment to the project by all the GOAHEAD partners and the DNW staff is gratefully acknowledged.

Author information

Author notes

  1. Kolja Kindler

    Present address: Max-Planck-Institute for Marine Microbiology, Celsiusstr. 1, 28359, Bremen, Germany

Authors and Affiliations

  1. Fluid Mechanics Department, Italian Aerospace Research Centre (CIRA), Via Maiorise, 81043, Capua, Italy

    Fabrizio De Gregorio

  2. German-Dutch Wind Tunnels (DNW), 8300 AD, Emmeloord, The Netherlands

    Kurt Pengel

  3. Institute for Aerodynamics and Flow Technology, German Aerospace Centre DLR, Goettingen, Germany

    Kolja Kindler

Authors
  1. Fabrizio De Gregorio
    View author publications

    You can also search for this author in PubMed Google Scholar

  2. Kurt Pengel
    View author publications

    You can also search for this author in PubMed Google Scholar

  3. Kolja Kindler
    View author publications

    You can also search for this author in PubMed Google Scholar

Corresponding author

Correspondence to Fabrizio De Gregorio.

Rights and permissions

Reprints and permissions

About this article

Cite this article

De Gregorio, F., Pengel, K. & Kindler, K. A comprehensive PIV measurement campaign on a fully equipped helicopter model. Exp Fluids 53, 37–49 (2012). https://doi.org/10.1007/s00348-011-1185-0

Download citation

  • Received:

  • Revised:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1007/s00348-011-1185-0

Keywords

Search

Navigation