Our present predictive capabilities for friction losses occurring in turbulent flow over rough surfaces include large uncertainties, especially for large scale inhomogeneous surfaces. The ridge-type surface structures of the present proposal are a model system for a spanwise variation in roughness that is widely employed in literature. The surface mounted ridges are oriented in streamwise flow direction. Previous work by our group has revealed that this simple surface geometry results in a complex drag behavior that can be classified by different drag regimes. The present project aims at investigating whether these drag regimes can be reproduced with different types of ridge geometries and which flow phenomena can be linked to the different drag regimes. We envisage that the obtained insights can provide important understanding for the further development of predictive roughness tools for inhomogeneous rough surfaces.
DFG Programme
Research Grants
