Project Details
Projekt
Highly accurate numerical simulation of wetting and dewetting on flexible substrates including Heat transfer
Applicant
Dr.-Ing. Florian Kummer
Subject Area
Fluid Mechanics
Term
since 2019
Project identifier
Deutsche Forschungsgemeinschaft (DFG) - Project number 422800359
The essence of this project is development of numerical simulation methods. The specific physics to be modeled, respectively simulated, is motivated by the practical experiments planned in the Priority Program 2171 (SPP 2171). In particular, experiments are to be investigated in which wetting or dewetting of flexible surfaces takes place. For this purpose, a corresponding high-precision numerical toolbox for the simulation of three-phase systems, consisting of a flexible solid as well as a liquid and a gaseous phase, was developed in the first funding phase. In the second funding phase of the program, these simulation techniques will be further improved and extended to cover a broader range of experiments. In particular, evaporation effects are now to be taken into account.It is important to note that simulation is a complement to the experiments in SPP 2171 here, as it can act as a magnifying glass, so to speak: it provides insights that experiment cannot. For example, simulations make it possible to determine quantities that are difficult or impossible to measure in experiments due to technical limitations.The complementary simulation of experiments of increasing complexity is planned. At the beginning there will be configurations with simple droplets and liquid bridges. In the further course, the impact behavior of droplets on flexible substrates will be investigated. Evaporation, by heating the substrate, will also be considered. The most challenging simulation, which concludes the project, is a Leidenfrost configuration, i.e. an evaporating droplet which, supported by its own vapor layer, hovers above a heated substrate.The simulation procedure is based on a numerical method for two-phase flows, developed by the applicants. These are mixtures of two immiscible fluids, in this case the printing ink and the ambient air. This setup is now supplemented by a third phase, i.e. a flexible solid. If air, liquid and solid meet, this is referred to as a three-phase contact line. The numerical-mathematical basis for this project is a so-called extended discontinuous Galerkin method, which was specially developed to simulate three-phase flows with contact lines with high accuracy. In particular, the interfaces between air and liquid, as well as the three-phase contact line can be followed with high accuracy. For the given problems, the method has to be combined with a simulation method for solids. Furthermore, the heat transfer as well as the evaporation have to be modeled.
DFG Programme
Priority Programmes
