Vision-2020, whose objectives include the reduction of emissions and a more effective transport systems, puts severe demands on aircraft velocity and weight. These require an increased load on wings and aero-engine components. The greening of air transport systems means a reduction of drag and losses, which can be obtained by keeping laminar boundary layers on external and internal airplane parts. Increased loads make supersonic flow velocities more prevalent and are inherently connected to the appearance of shock waves, which in turn may interact with a laminar boundary layer. Such an interaction can quickly cause flow separation, which is highly detrimental to aircraft performance, and poses a threat to safety. In order to diminish the shock induced separation, the boundary layer at the point of interaction should be turbulent.
The main objective of the TFAST project is to study the effect of transition location on the structure of interaction. The main question is how close the induced transition may be to the shock wave while still maintaining a typical turbulent character of interaction.
The main study cases (shock waves on wings/profiles, turbine and compressor blades and supersonic intake flows) will help to answer open questions posed by the aeronautics industry and to tackle more complex applications. In addition to basic flow configurations, transition control methods (stream-wise vortex generators and electro-hydrodynamic actuators) will be investigated for controlling transition location, interaction induced separation and inherent flow unsteadiness. TFAST for the first time will provide a characterization and selection of appropriate flow control methods for transition induction as well as physical models of these devices.
Emphasis will be placed on closely coupled experiments and numerical investigations to overcome weaknesses in both approaches.