Experimental and Numerical Analysis of the Microlayer Development underneath Nucleating Bubbles on Hydrophobic Textured Surfaces

• Applicant: Professor Dr.-Ing. Uwe Hampel
• Subject Area: Chemical and Thermal Process Engineering
• Term: since 2026
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 577208610

Bubble nucleation is a phenomenon that occurs in boiling, but also in electrolysis and during other gas-producing chemical reactions. In the field of heat transfer, boiling is a highly efficient mechanism and thus fundamental to many energy conversion systems, such as solar and conventional power plants, electronics cooling, data center cooling, rocket engine cooling, cryo-cooling, nuclear reactors and others. We also speak of sub-cooled boiling, because the heater wall and the liquid in the thermal boundary layer near the heated surface have a temperature above, and the bulk liquid has a temperature below saturation temperature. Over the past decades, understanding and modelling of nucleate boiling has attracted considerable attention of many researchers as it is key to designing and optimizing high power heating and cooling systems. In particular, the microlayer evaporation is considered a key heat transfer mechanism in nucleate boiling but its dynamics yet lacks full understanding. The objective of the planned work is to examine the microlayer formation on hydrophobic surfaces using synchrotron X-ray imaging and then to understand its development. Following that, we investigate how the surface microstructure alters the microlayer morphology. The proposed work will not be limited to nucleate boiling. It can be extended to all nucleation related processes such as in water electrolysis and other gas producing chemical reactions.

• DFG Programme: Research Grants