ABSTRACT
The successful developments of computational techniques provide nowadays robust and stable algorithms for the simulation of systems involving interfaces. Molecular dynamics (MD) and computational fluid dynamics (CFD) are two techniques commonly used to numerically describe such systems. To illustrate the capabilities of both techniques, this chapter will present simulations of simplified systems consisting of surfactant monolayers at water/air interfaces and water droplets in a continuous paraffin oil phase. The goal of this chapter is hence not to present a detailed review of all the running challenges in the simulation of interfaces. It essentially aims to put emphasis on the opportunities offered by CFD and MD in the field of interfacial chemistry. Such systems have a major applicative importance since their understanding is fundamental in a large variety of research domains and in many industrial applications. The dispersion of two immiscible liquids, such as in emulsions, is, for example, commonly found in many technical processes with major importance in chemical, pharmaceutical, petroleum, and food industries (Binks 1998; Bourrel and Schechter 1988; Dickinson 2003; Léal-Calderon et al. 2007; Salager 2000). This is also the case for liquid droplets in a gaseous phase like in sprays (Charles 2012). Emulsions and sprays both involve liquid free interfaces and hence lead to the same difficulties when trying to simulate their behavior. Besides these practical issues, challenging applied mathematics questions also appear in the simulation of free-surface systems. In the simple case of evaporating sessile droplets, solid, liquid, and gaseous phases simultaneously come into play. The simulation of heat and mass transfers as
11.1 Introduction ............................................................................................221 11.2 MD Applied to Surfactant Monolayers ........................................................226 11.3 Numerical Approach of Heterogeneous Continuous Media ......................... 232 11.4 Simulation of Droplet Hydrodynamics ......................................................... 238 11.5 Conclusions ................................................................................................... 247 Acknowledgments ..................................................................................................248 References ..............................................................................................................248
