Sticking and sliding in contact between a solid body and a fluid

• Applicant: Professor Dr. Valentin L. Popov
• Subject Area: Mechanics
• Term: since 2025
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 554322826

In macroscopic hydrodynamics, it is usually assumed that a fluid at the boundary of a solid body has the same velocity as the solid body itself. However, this sticking condition is not universal. In nanotribology and nanofluidics, it was found that liquids can sometimes slide along solid boundaries. However, there is almost no systematic research into the conditions for sliding at the solid-liquid interface and the friction force appearing during sliding. Research into such boundary conditions and development of corresponding technologies could represent a breakthrough both in nanotechnologies and in some macroscopic hydrodynamic applications. The present project is dedicated to a preliminary qualitative analysis of a number of phenomena that can be the cause for the sliding condition at the solid-fluid interface (feasibility study). The question to be answered is: Is the sliding boundary condition possible in a contact between a solid body and a liquid on a macroscopic scale and if so, what are the main factors that favor the violation of the usual sticking condition?

• DFG Programme: Research Grants