The proposal covered the preparation and performance of a wind tunnel test using an innovative Bizjet with natural laminar flow wings, RC-controlled HTP and nacelles.
Model design, manufacturing and instrumentation were supported for achieving a high-quality model for a test in cryogenic environment. The tunnel was instrumented for performance tests on a z-sting mounted full model acquiring forces, moments as well as steady and unsteady pressure data. Transition location on the wings were assessed using temperature sensitive paint. Wing shape was determined with a stereo camera system.
Final data and images were going to be provided to the topic manager. Risk assessment and a dissemination plan were provided.
The “Vision 2020” goals, introduced in 2001 by the European Union, require breakthrough achievements related to drag reduction and propulsion efficiency. Laminar flow technology was identified as a promising candidate to contribute to this objective, as the extended laminar flow region allows a strong decrease in skin friction drag. Laminar flow may be achieved by shape modification (Natural Laminar Flow, NLF) or surface -suction (Hybrid Laminar Flow Control, HLFC).
In the past, a number of flight demonstrators were successfully used in the USA and Europe. Flight tests were selected as they allow full system demonstration at flight Reynolds numbers, which were not achievable in conventional wind tunnels, e.g. the maximum chord Reynolds number in a transition test in transonic flow in the ONERA S1MA wind‐tunnel facility was about 10 million. On the other hand, such flight tests were much too expensive to allow for extensive parametric exploration and optimization.
As the ETW cryogenic wind tunnel allows for full model testing chord Reynolds numbers up to 50 million by combining testing at cryogenic temperatures (down to 110 K) and increased pressures (up to 4.5 bar), the European Research project TELFONA, led by Airbus, was launched to demonstrate the use of ETW for NLF wing design validation at high Reynolds numbers.