| Wed June 28th 2023 16:00 – 17:00 ZH286 | Seminar | Including thermal effects in modeling and computing dynamics of thin films Lou Kondic |
Details:Modeling thermal effects and their influence on dynamics of thin films and drops is of relevance in a number of different problems, and on the length-scales that range from nano to micro and macro. The common feature is that one needs to consider a complicated setup such that the dynamics of films and drops modifies the heat flow, which in turn influences the fluid dynamics due to temperature dependence of fluid material properties, such as surface tension and viscosity. Therefore, one needs to come up with a self-consistent approach that considers coupling of fluid and thermal effects. A significant simplification is however possible for thin films and/or drops: in such a case it is possible to reduce the problem to a simpler one by carrying out asymptotic analysis which is similar in spirit to the approach used for deriving well known thin-film equation. The outlined approach is illustrated by considering metal films of nanoscale thickness, exposed to external heating by nanosecond laser pulses: such pulses melt the film which then evolves and breaks up into droplets. One unusual feature of this setup is that that the heating is volumetric due to the fact that the film thickness is comparable to thermal absorption length: therefore, not only heat conduction, but also heat absorption depends on the film thickness. Combining asymptotic analysis with novel GPU-based simulation allows to consider film evolution in large computational domains and explore the relevance of thermal effects during nonlinear stages of evolution. | ||
