ETW - LoCaRe

LuFo V-3 Project LoCaRe

Title: Localisation and Characterisation of Flight Relevant Noise Sources on High Lift Systems &
Innovative Experimental Investigations on Natural Laminar Flow Control at Flight Reynolds numbers

Leader: ETW GmbH, Partners: DLR e.V., Embraer

The LuFo research project LoCaRe was based on an established and successful cooperation between ETW, DLR and Embraer. It sustainably improved the capabilities of ETW and DLR to support the development of particularly low-noise and fuel-efficient aircraft.

On the one hand, ETW was enabled to contribute to localising sources of noise that occur during take-off and landing on high lift systems at an early stage of development. DLR provided the measurement methodology and investigate the physics of typically occurring phenomena, and Embraer compared the results with its own flight test data, evaluate and confirmed the methodology. On the other hand, ETW and DLR expanded the technical and methodological basis for efficiently and effectively supporting the development and application of future low-drag laminar wings. Embraer validated the new methods by using a research configuration as a sample application.

In both areas, the cooperation with Embraer not only contributed toward further development of the capabilities at ETW and DLR, but also established them for application in aircraft research and development (R&D). LoCaRe increased the competitiveness of ETW and DLR and strengthened R&D capabilities in Germany, which are valuable and required to enable sustainable aviation.

This work received funding from the German Federal Ministry for Economic Affairs and Climate Action LuFo V-3/2018-2022 under grant agreement no 20A1701A.

Research Projects Contact

The Manager Operations & Administration ensures, administers, and enhances efficient and effective operation of ETW. This task includes the initiation and advancement of research projects with ETW participation.

Dr.-Ing. Peter GUNTERMANN

Dr.-Ing. Peter GUNTERMANN
Manager Operations & Administration
Tel.: +49 (2203) 609-113
E-Mail:

Main LoCaRe topics

Flight relevant noise sources

The comparison of aircraft overflight results with investigations in conventional wind tunnels have shown differences in terms of the location and intensity of noise sources. It is highly likely that some of the aerodynamics causing noise strongly depends on the correct represention of the boundary layer flow, thus, on the flow parameter Reynolds number. In order to reduce the noise emmisions of future aircraft, high Reynolds number wind tunnel tests at ETW shall provide added value. ETW strives to perform noise source localisation piggyback to take-off and landing aerodynamic performance testing. This was successfully applied to a semi-span model in a closed test section, and shall be extended to full-span models in a slotted test section configuration. A comparsion with flight test data shall prove the validity of the concept.

Laminar testing and drag reduction

In order to save energy and fly eco-efficiently, the drag of an aircraft has to be minimal. The aircraft surface is partly covered by a so-called laminar low-drag boundary layer, and further downstream by a turbulent one. A promising concept to minimise drag is to delay the laminar-turbulent boundary-layer transition downstream, and to maximise laminar flow areas. The physics of the transition process strongly dependends on the inflow disturbances and the boundary layer above the aircraft surface. High Reynolds number wind tunnel tests at ETW can simulate the physics close to reality in a natural and well reproducible manner, and boundary-layer transition can be accurately located. LoCaRe will assess ETW's spectral inflow disturbances in detail, and improve ETW's capabilities for laminar testing and supporting laminar aircraft design.