Despite the paramount importance of wall turbulence in various engineering applications–including pipelines, wind turbines, cars, planes, ships, etc.–several critical questions persist unanswered. This proposal centers on investigating two primary research questions:
- (i) the influence of Reynolds number on rough-wall turbulence, emphasizing inner/outer region interactions, and
- (ii) the effects of wall curvature and its interplay with pressure gradients.
Insights gained from this research helps informing drag reduction strategies via wall roughness, propose reduced-order models to account for the effect of Reynolds number and inner/outer interactions (such as modulation) in the presence of roughness, and enhance turbulence models to account for wall curvature, pressure gradient, and their interaction.
Beyond practical implications, the study holds significant fundamental value. Given the complex nature of the phenomena under investigation and the numerous unknowns involved, full spatio-temporal resolution of all turbulent structures is imperative. This warrants the use of computational methods and accurate direct numerical simulation (DNS) in particular. Given the scale of these simulations–demanding up to 20 billion grid points and multiple configurations for each flow setup–access to Tier-0 high performance computing (HPC) resources is crucial. In particular, GPU-accelerated codes on LUMI-G will be the only way to tackle these turbulence problems.
Philipp Schlatter, Friedrich-Alexander-Universität Erlangen-Nürnberg, Germany