CEAS Aeronautical Journal

, Volume 7, Issue 2, pp 185–207 | Cite as

Numerical investigations of Fenestron™ noise characteristics using a hybrid method

  • Jae Hun YouEmail author
  • Christian Breitsamter
  • Rainer Heger
Original Paper


The present article gives an overview of numerical investigations performed during a research project aimed at in-depth understanding of noise generation mechanisms of a shrouded helicopter tail rotor such as Airbus Helicopters Fenestron\(^\mathrm{TM}\). Both aerodynamic and aeroacoustic studies are performed based on a full-scale lightweight transport helicopter configuration with detailed geometry of the Fenestron\(^\mathrm{TM}\) and by neglecting of the main rotor downwash effect. Analysis is carried out by using a hybrid method, combining Unsteady Reynolds-Averaged Navier-Stokes (URANS) simulation with Ffowcs Williams and Hawkings (FW-H) acoustic analogy. Two representative helicopter flight conditions, namely fast forward flight and hovering, are considered. Thereby, it is intended to assess the influence of cross flow in forward flight condition on the Fenestron\(^\mathrm{TM}\) acoustic property. Effect of turbulence model on the accuracy of noise prediction is also investigated by comparing the Shear Stress Transport (SST) turbulence model with the Scale Adaptive Simulation (SAS). The capability of the applied hybrid methodology is estimated by means of flight test measurements. A good agreement is found between the predicted and measured sound spectra in terms of blade passing frequency (BPF) and its corresponding sidebands for both flight conditions investigated.


Shrouded helicopter tail rotor Fenestron\(^\mathrm{TM}\) URANS FW-H Scale Adaptive Simulation (SAS) 



This work has been supported by the Bayerische Forschungsstiftung (BFS) within the frame of the FORLärm project. The support of these investigations by the Airbus Helicopters Deutschland GmbH is gratefully acknowledged. The authors wish to thank ANSYS, Inc. for providing the flow simulation software CFX. The authors would also like to thank C. Scheit, M.Sc. and Dr. S. Becker from the Lehrstuhl für Prozessmaschinen und Anlagentechnik, Universität Erlangen-Nürnberg for providing their in-house FW-H code SPySI. Computer resources for this project have been provided by the Gauss Centre for Supercomputing/Leibniz Supercomputing Centre under grant: pr83nu.


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Copyright information

© Deutsches Zentrum für Luft- und Raumfahrt e.V. 2016

Authors and Affiliations

  • Jae Hun You
    • 1
    Email author
  • Christian Breitsamter
    • 1
  • Rainer Heger
    • 2
  1. 1.Institute of Aerodynamics and Fluid MechanicsTechnische Universität MünchenGarchingGermany
  2. 2.Airbus Helicopters Deutschland GmbHDonauwörthGermany

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