Final Report Summary - WALLTURB (A European Synergy for the assessment of wall turbulence)
Europe seeks to reduce aircraft development and operating costs in the short and long terms. This must be accomplished both through improved aircraft performance and through reduction in maintenance and other direct operating costs. To reach these objectives, the aeronautical industry needs improved models based on a deeper understanding of the physics, which in turn must be acquired using the most advanced experimental and modelling methods. While this is true for all the aspects of the design and operation of an aircraft, it is particularly true for aerodynamics. Although aerodynamics has made tremendous progress in the last century, it still lacks reliable turbulence models (which are crucial also for many other industrial design problems) and the understanding to develop them. The search for these models remains a very active domain for research and improvement. In fact, turbulence remains one of the great unsolved riddles of engineering and natural sciences, nowhere more so than for flow near surfaces.
The WALLTURB project was a challenging research program within the objectives of the EU in Aeronautics and of strong industrial interest at intermediate and long term. The global aim of WALLTURB was to bring a significant progress in the understanding and modelling of near wall turbulence in boundary layers.
To reach these objectives, the WALLTURB consortium took advantage of the recent progress in the experimental and numerical approaches of turbulence and the complementary skills of leading teams in Europe working on turbulence. It has generated a large and original database, with recent and relevant data about near wall turbulence. This database was shared by the partners to extract relevant physical data and will be used by the scientific community in the next years.
This database comprises new experimental and DNS data, giving new insights into both zero and adverse pressure gradient turbulent boundary layer physics, with and without separation. This database was used by the partners in the frame of WALLTURB to improve RANS, and LES near wall turbulence models and to investigate LODS / LES coupling near the wall. The work performed has allowed development of new turbulence models and the assessment of the relative merits and drawbacks of these models. These models were also evaluated by AIRBUS in the industrial context. It has also generated new physical insights, both with regard to classical scaling laws (on which most models to-date have been based) and turbulent structures (on which future models will most likely be based.)
Globally, it should be said that, although the time scale of turbulence model development is much larger than that of this project, the WALLTURB consortium can claim that a real step forward was done, thanks to the unique possibility offered by this type of project: a tight cooperation, at the highest level of competence, between scientists of different origins and different skills, supported by a good amount of funding.
The WALLTURB project was a challenging research program within the objectives of the EU in Aeronautics and of strong industrial interest at intermediate and long term. The global aim of WALLTURB was to bring a significant progress in the understanding and modelling of near wall turbulence in boundary layers.
To reach these objectives, the WALLTURB consortium took advantage of the recent progress in the experimental and numerical approaches of turbulence and the complementary skills of leading teams in Europe working on turbulence. It has generated a large and original database, with recent and relevant data about near wall turbulence. This database was shared by the partners to extract relevant physical data and will be used by the scientific community in the next years.
This database comprises new experimental and DNS data, giving new insights into both zero and adverse pressure gradient turbulent boundary layer physics, with and without separation. This database was used by the partners in the frame of WALLTURB to improve RANS, and LES near wall turbulence models and to investigate LODS / LES coupling near the wall. The work performed has allowed development of new turbulence models and the assessment of the relative merits and drawbacks of these models. These models were also evaluated by AIRBUS in the industrial context. It has also generated new physical insights, both with regard to classical scaling laws (on which most models to-date have been based) and turbulent structures (on which future models will most likely be based.)
Globally, it should be said that, although the time scale of turbulence model development is much larger than that of this project, the WALLTURB consortium can claim that a real step forward was done, thanks to the unique possibility offered by this type of project: a tight cooperation, at the highest level of competence, between scientists of different origins and different skills, supported by a good amount of funding.
