European Commission logo
English English
CORDIS - EU research results
Content archived on 2024-05-29

Testing for laminar flow on new aircraft

Final Report Summary - TELFONA (Testing for laminar flow on new aircraft)

The main objective of the TELFONA project was to demonstrate the ability to predict NLF aircraft performance in flight based on wind tunnel test and CFD results. This capability would allow industry to validate the design of such an environmentally friendly aircraft concept.

In order to achieve this objective, a number of supporting objectives were defined as listed below:
- Calibration of the ETW facility for testing laminar flow aircraft;
- Integration of receptivity modelling into transition prediction methods;
- Flight performance methods for a laminar flow aircraft;
- Development of technology for future hybrid laminar flow control testing;
- Validation of developed methods.

The performance wing test results were used along with CFD results by Airbus and Piaggio to develop a method of predicting the in-flight performance of an NLF aircraft. These calculations showed how the drag due to turbulent wedges could be accounted for.

Alongside these two major design and test activities, other partners performed support tasks aimed at improving the tools and techniques associated with laminar flow wing design. ITAM worked to develop a new cryogenic hotwire technique based on using a constant current anemometer. This new device was tested in the smaller pilot ETW facility. ETW also collaborated with DLR and TU Berlin to examine how the existing model manufacturing and test techniques would have to be extended if a Hybrid laminar flow control (HLFC) wing were to be tested. HLFC introduces the additional complexity of using suction through a porous wing skin along with the aerofoil shape to delay transition.

Additional wind tunnel testing was done by KTH and Tsagi to gather data for calibrating receptivity models. Receptivity models are currently not used during the wing design process but will allow the wing's surface quality and the turbulence and noise levels in the environment to be accounted for when predicting transition. DLR, Imperial College, KTH and Tsagi have contributed to the development of these receptivity models although the original objective of integrating these techniques into transition prediction methods remains to be achieved.

The tools and design knowledge that has been gathered in the project is now being applied within the smart fixed wing aircraft part of the JTI clean sky to design a natural laminar flow flying demonstrator. The research organisations and universities in TELFONA will continue to build upon the knowledge gained within the project to develop receptivity modelling software. These new tools will be deployed by industry in the longer term. A number of new measurement techniques will be available for future use including cryogenic hotwires and pressure sensitive copolymers.