This open access book explains the wetting of surfaces by fluids or their dewetting plays an important role in numerous processes in production engineering, energy technology and process engineering. However, the mutual influences between the dynamic wetting and dewetting processes and the local transport processes in terms of momentum, energy or material are not sufficiently understood and predictable, especially when the fluids and surfaces are complex and the processes are transient. The Collaborative Research Center 1194 of the German Research Foundation (CRC 1194) has derived 5 overarching goals for its research program: (1) In-depth understanding of the relationships and mechanisms of action of local momentum, heat and mass transport processes on wetting properties and vice versa; (2) Development of physically based, mathematical models, numerical methods and freely available simulation programs; (3) Development of high-resolution measurement methods for the experimental analysis of the interactions of transport and wetting processes, including the establishment of new measuring instruments; (4) Demonstration of the possibilities of targeted influencing and optimization of wetting processes by transport processes and vice versa; (5) Exemplary research into new and improved processes for selected, technically relevant applications. To achieve these goals, researchers from different disciplines (engineering, mathematics, natural sciences) work together in the CRC using complementary methods. This allows the processes to be investigated experimentally, theoretically and numerically on different length scales (nano-micro-meso-macro). In addition, a bridge is built between basic research and application-oriented research. The CRC comprises three project areas: (A) Generic Experiments (B) Modeling and Numerical Simulation and (C) New and Improved Applications. Two generic guiding configurations and OpenFOAM as a common software platform were established as important integrative brackets and for the common focus. The guiding configurations immersion body and droplet are, on the one hand, independent generic experiments that address complementary scientific questions and, on the other hand, arrangements that are taken up in numerous other experiments and that serve to validate the simulation models. In the last funding period, the focus lied on consolidating the comprehensive understanding and description of various coupled phenomena while further increasing the complexity of the fluids and surfaces. In addition, the transfer of measurement technology was accelerated.
Table of Contents:
Forced wetting and de-wetting on complex surfaces – Generic configuration immersed body.- Experimental investigation of coalescence and breakup of droplets on solid surfaces – Generic configuration sessile drop.- Investigation of fast de-wetting from substrates with complex surface morphologies.- Flow and evaporation of pure liquids and (nano)-suspensions from structured coatings.- Wetting and transport on swellable, immobilized polymer brushes and polymer networks.- Flow velocity profile near a moving three-phase contact line.- Raman spectroscopy for investigating mass transport and concentration gradients in mixtures.- Spatially resolved NMR for investigating fluid behavior on solid surfaces.- Nanoscale investigation of wetting and de-wetting during imbibtion and nucleation.- Modeling and VOF-based multiphysics simulation of irreversible thermodynamic transfer processes at dynamic contact lines.- Direct numerical simulation of locally coupled interface processes at dynamic contact lines.- Simulation-based optimization and optimal design of experiments for wetting processes.- High order schemes for direct numerical simulation for wetting and de-wetting problems based on the discontinuous Galerkin method.- Scale bridging simulation of dynamic wetting based on the phase field method.- Forced wetting with hydrodynamic assist on gravure print cylinders.- Multiscale investigations of boiling of complex fluids on complex surfaces.- Condensation of water on hydrophobic, structured surfaces.- Controlled dynamic wetting and the influence of ionic mass transport in mesoporous films.- Contact line dynamics and diffusion-driven nucleation during cavitation.- Surface characterization by drops on an inclined plane.- Research data management.- Management of research collaboration.
About the Author :
Peter Stephan is Full Professor at TU Darmstadt and head of the Institute of Technical Thermodynamics. His research spans heat and mass transfer, interfacial phenomena and thermo fluid systems. He served as Spokesperson of CRC 1194. He is spokesperson of TU Darmstadt's Research Field "Energy & Environment", Vice President of the International Centre for Heat and Mass Transfer and holds editorial positions in several leading heat transfer journals.
Dieter Bothe is Full Professor at TU Darmstadt and head of the Institute for Mathematical Modeling and Analysis. His research focuses on two-phase flows and transport phenomena at fluid interfaces combining continuum-thermodynamical modeling, mathematical and computational analysis, numerical methods, and research software engineering. He served as Co-Spokesperson of the CRC 1194. He is coordinator of TU Darmstadt's research profile topic "Thermo-Fluids & Interfacial Phenomena", associated editor of the international journal "Nonlinear Analysis: Real World Applications" and serves on the editorial advisory board of the "International Journal of Multiphase Flow".
Benjamin Lambie is Managing Director of the TU Darmstadt's Research Field "Energy & Environment", where he also managed the CRC 1194 and coordinated major collaborative research programs. His background spans thermo fluids, multiphase flow systems, research management and digital transformation. He holds a PhD in Mechanical Engineering from TU Darmstadt and previously contributed to the Smart Interfaces Excellence Cluster as researcher and innovation lead.
