© TEENI Consortium, 2008

Turboshaft Engine Exhaust Noise Identification


TEENI deals with experimental identification of the contributions of each of the engine modules to exhaust Broadband Noise emission. This noise component is the second most dominant noise source of a Turboshaft engine, and installing acoustic liners on the exhaust can lead to significant benefit for reducing noise levels from helicopters.

Turboshaft exhaust noise is taken to be a mix of combustion and turbine noise, with very little jet noise. It is representative of what is generally called core noise on aircraft engines. Therefore, it should also help with the understanding of this difficult subject, as a result of its simpler geometry and absence of parasitic noise sources (such as jet and fan noise).

The TEENI work programme is divided in 3 interdependent Workpackages (WP):

- WP1 : Innovative sensors development - to provide reference measurements of fluctuating quantities within the engine under harsh operating conditions.

- WP2 : Noise Sources Breakdown Techniques (NSBT) development - to determine the dominant emission location/s from external measurements. Several techniques will be evaluated, both internal and external measurements will be undertaken, and, various formalisms and approaches will be considered. Propagation through turbine/s and tools to help take into account individual engine noise sources will also be developed.

- WP3 : An Ardiden 1H Turboshaft engine full-scale test - to include and test the developed sensors, to verify (through correlation with internal sensors), to assess the pertinence of the various NSBT and to provide an initial example of noise decomposition per module.

In order to reduce development risks, both sensors and methods will be tested within their relative WP before the engine test.

The major deliverables of TEENI will be:

  • A set of sensors for measuring unsteady quantities, suitable for full-scale engine testing (650°<T<1000°C)
  • A noise breakdown technique selected from a set of methods as a result of comparisons with data from an engine noise database
  • A thorough understanding of noise generation, propagation and radiation through the exhaust
  • A comprehensive full-scale engine test database
  • A ranking of exhaust noise sources, with a recommendation on the noise source to be reduced in priority, through appropriately tuned liners in the exhaust duct.

Project Coordinator


  • AVIO (IT)
  • Brí»el & Kjaí«r (DK)
  • DLR (DE)
  • EPFL (CH)
  • Microflown Technologies (NL)
  • ONERA  (FR)
  • TCD (IE)

Project status

Start Date : 2008-04-01
End Date : 2013-03-31
Duration : 60 months
Project Status : Closed
Programme Type : 7th FWP (Seventh Framework Programme)


18 Month- Publishable summary

60 Month- Publishable summary