The reduction of aircraft drag is of major interest to the aeronautical industry. Drag reduction provides clear economic benefits in terms of fuel savings, extended operational range and/or increased payload. In addition, reductions in fuel consumption will have a direct beneficial effect upon environmental pollution levels. The laminar flow concepts offers the largest performance gain of any single technology. Thus the main objectives of this project are to prove the basic concepts of this technology and to prepare the tools, methods and systems required for its successful application to a wide range of practical airframes, from small subsonic commuters to large transonic transport aircraft.
The first phase of the project was successful. All objectives have been reached. The numerical tools developed and experimental data collected in the project will be applied and analyzed in more detail in the ELFIN II project.
Wind tunnel test of the Hybrid Laminar Flow Control (HLFC) concept on a large-scale wing model with perforated leading edge. Two suction philosophies will be investigated; discrete lower surface suction for flow stabilization downstream of minor surface discontinuities, and extensive distributed leading-edge suction for stabilization of high sweep, high Reynolds number flows.
Testing techniques and suction device development for wind tunnel and flight testing. The full exploitation and adaptation of the laminar flow concept relies upon improvements in and modification to existing measurement techniques for use in industrial wind tunnels and under flight conditions. The suction methodology and associated systems as required in the wind tunnel test and also for practical aircraft application will be developed and supplied.
Boundary layer and transition prediction methods for laminar wing design application. Accurate laminar boundary layer calculations are vital for reliable transition prediction. Existing stability codes utilize an empirical correlation for transition prediction. These codes will be extended to include important terms previously neglected. Database methods will be developed as practical and efficient design tools and direct simulation studies will be initiated as a long term solution to transition prediction.
Flight test with Natural Laminar Flow glove. Flight testing of laminar part-span wing glove (on F100 aircraft ), to provide design criteria, wind tunnel correlation and CFD method validation.
Funding SchemeCSC - Cost-sharing contracts
16451 Argyroupolis -Athina
80038 Pomigliano D'arco - Napoli
GU14 6YU Farnborough
1100 AE Amsterdam
28850 Torrejon De Ardoz
581 88 Linköping
2629 HS Delft
BS8 1TR Bristol, Clifton
M13 9PL Manchester