Experiments in Fluids

, 60:62 | Cite as

Performance improvements of helicopter basic fuselage model by passive vortex generators

  • Fabrizio De GregorioEmail author
Research Article


Wind-tunnel tests of a heavy-class helicopter model were carried out to evaluate the effectiveness of a passive flow control system in alleviating fuselage parasite drag. An array of counter-rotating vortex generators was installed to reduce/remove the flow separation occurring on the rear-loading ramp responsible for the high-pressure drag. Novel technical solutions for the VGs’ design and location were selected compared to the previous work. A geometrically scaled 1:7 basic fuselage of a heavy-class helicopter was investigated with and without a passive flow control system using various measurement techniques. In particular, pressure measurements and stereo particle image velocimetry surveys were performed to obtain physical insights into load measurements. This paper reports promising results from wind-tunnel experiments, including the observation of significant drag reduction for a wide range of fuselage angles of attack and side slip angles without a negative impact on other aerodynamic characteristics.

Graphical abstract

List of symbols


VG base (m)


Fuselage drag coefficient, drag/(qACS)


Fuselage lift coefficient, lift/(qACS)


Pressure coefficient, (p − ps)/q


Fuselage drag force in the wind axis (N)


Fuselage height (maximum) (m)


VG height (maximum) (m)


Fuselage length (m)


VG length (m)


Reynolds number, U L/ν

\({U_\infty }\)

Freestream velocity (m/s)


Vortex generator


Fuselage width (maximum) (m)


Normalized streamwise coordinate


Normalized spanwise coordinate


Normalized vertical coordinate


Fuselage angle of attack (°)

\({\alpha _{{\text{VG}}}}\)

VG pitch angle (°)


Fuselage yaw angle (°)


Boundary layer displacement thickness


Upsweep angle (°)


Kinematic viscosity (m2/s)


Density (kg/m3)



The work has been partially founded by the European Union in the framework of the Clean Sky Joint Technology Initiative under grant agreement number: CSJU-GAM-GRC-2008-01. The author would like to acknowledge P. L. Vitagliano, G. Ceglia, G. Spaziani, F. Michaux, S. Kallweit and the LWTE colleagues for the valuable support provided during the measurement campaign. A special thank you to my friend Prof. Nathan Tubliz for his help in making the article legible.


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Copyright information

© Springer-Verlag GmbH Germany, part of Springer Nature 2019

Authors and Affiliations

  1. 1.Aerodynamic and Icing Measurement Methodologies LaboratoryItalian Aerospace Research Centre-CIRACapuaItaly

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