Automotive, aeronautic, and maritime transport of people and goods play important roles in the globalised world, but are also using up about five billion barrels of oil per year. Roughly half of the energy being spent worldwide in such transport activities is dissipated by undesired turbulent motion in the interface between moving objects and surrounding fluid. The knowledge of the behaviour of turbulence close to these surfaces is of paramount importance if optimal design and perhaps drag reduction via ow control is attempted.

Accurate numerical simulations allow the characterisation, with the highest level of detail, of the multiple physical phenom- ena present in complex ow cases such as around airplane wings. The physics includes the change from laminar to turbulent flow, developed turbulence, separation and the structure of the turbulent wake. In this project we use large-scale numerical simulations (so far with up to 3.2 billion grid points) to analyse the flow around an idealised wing.

Numerical experiments in a “virtual wind tunnel” and the concept of “virtual wind tunnel” aims at replacing, in the future, some real wind-tunnel experiments by corresponding simulations, which will yield a much larger wealth of data relevant for design purposes.

Figure. Three-dimensional visualisation of turbulent vortices in the ow around a NACA4412 wing section simulated in the “virtual wind tunnel”.