Statistics and intermittency of developed channel flows:: a grand challenge in turbulence modeling and simulation

Studying and modeling turbulence in wall-bounded flows is important in many engineering fields, such as transportation, power generation or chemical engineering. Despite its long history, it remains disputable even in its basic aspects and even if only simple flow types are considered. Focusing on the best studied flow type, which has also direct applications, we argue that not only its theoretical description, but also its experimental measurement and numerical simulation are objectively limited in range and precision, and that it is necessary to bridge gaps between parameter ranges that are covered by different approaches. Currently, this can only be achieved by expanding the range of numerical simulations, a grand challenge even for the most powerful computational resources just becoming available. The required setup and desired output of such simulations are specified, along with estimates of the computing effort on the NEC SX-8 supercomputer at HLRS.