Droplets under gradients of temperature and velocity by atomistic simulation
The behavior of droplets under strong non-equilibrium conditions is not well understood. With respect to heat and mass transfer phenomena, a decisive role is played by their fluid phase interface. Because of its typically very small spatial extent, processes across the fluid phase interface can directly be studied with atomistic molecular dynamics simulation, which allows for a detailed insight on a sound physical basis. Strong driving force gradients for heat and mass transfer are beneficial for this approach since they increase the signal-to-noise ratio of such calculations.
In the present project, liquid and vapor phases that interact with each other via their interface are studied under non-equilibrium conditions by means of relatively large atomistic systems. Evaporation of droplets is addressed directly. Next to pure fluids, mixtures containing several components are considered. Force field models for the description of the molecular interactions are available from preceding work, e.g. for acetone or nitrogen.
The influence of temperature and velocity gradients on heat and mass transfer will be studied together with the physical properties of the interface. It is aimed at a phenomenological model for evaporation based on molecular dynamics simulation series. The extended critical region, being associated with a spatially significantly extended interface, will be studied as well. In cooperation with other projects of SFB-TRR75, experimental scenarios will be modelled. Data based on atomistic simulations will be supplied for comparisons to CFD and dynamics density functional theory calculations. Moreover, thermodynamic property data will be predicted, particularly for transport diffusion.