Cutting-Edge Turbulence Simulation Methods for Wind Energy and Aerospace Problems

The availability of reliable and efficient turbulent flow simulation methods is highly beneficial for wind energy and aerospace developments. However, existing simulation methods suffer from significant shortcomings. In particular, the most promising methods (hybrid RANS-LES methods) face divergent developments over decades, there is a significant waste of resources and opportunities. It is very likely that this development will continue as long as there is little awareness of conceptional differences of hybrid methods and their implications. The main purpose of this paper is to contribute to such clarification by identifying a basic requirement for the proper functioning of hybrid RANS-LES methods: a physically correct communication of RANS and LES modes. The state of the art of continuous eddy simulations (CES) methods (which include the required mode communication) is described and requirements for further developments are presented.