Drag of heterogeneous rough surfaces

• Applicant: Professorin Dr.-Ing. Bettina Frohnapfel
• Subject Area: Fluid Mechanics
• Term: since 2025
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 561486292

Surfaces subject to turbulent flow experience greater flow resistance if the surfaces are rough. Rough surfaces therefore result in increased energy requirements in the transport sector, the assessment and prediction of which is an important basis for the design and operation of pipelines, aircraft or container ships. Currently available prediction tools for the global drag of objects with rough surfaces contain large uncertainties. In consequence a wide variety of research work is being carried out to enable an improved prediction of the flow resistance of rough surfaces. The present project belongs to this research field and is particularly dedicated to heterogeneous rough surfaces, i.e. surfaces whose roughness properties vary spatially. A clear need for research into this type of surface roughness has been identified in recent review articles. This concerns both the lack of reference data for the global frictional resistance of heterogeneous rough surfaces and the lack of models to predict it. These two topic areas are addressed in the present proposal using a combined experimental-numerical approach. The proposed research program builds on the expertise available at the Institute of Fluid Mechanics in the area of measuring and simulating turbulent flows over rough surfaces and the resulting data analysis.

• DFG Programme: Research Grants