A diffuse-interface model for multiphase flow with surface-active particles

• Applicant: Professor Dr. Sebastian Aland
• Subject Area: Mathematics
• Term: from 2013 to 2017
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 237910870

Our goal is to use diffuse-interface models to describe complex interfacial phenomena arising in microprocess engineering, microfluidics and materials sciences. Thereby we will derive efficient numerical algorithms using adaptive methods and high performance computing with highly scalable domain decomposition. To discretize in time we propose new implicit and semi-implicit schemes which allow dealing with high surface tensions (i.e. small length scales) while maintaining dissipation properties. We consider three exciting scenarios involving soluble surfactants, mass transfer and interfacial nanoparticles. - For the soluble surfactants we will conduct simulations on Taylor bubbles which will allow code-tocode and model-to-model comparisons among the members of this SPP. Together with K.Eckert* we will try to improve the understanding of Marangoni pattern formation driven by surfactant mass transfer. - To account for mass transfer of dissolving bubbles we will develop the first phase-field model including bubble volume change. After proving mass conservation and asymptotic convergence to the sharp interface model, we will apply this model to dissolving Taylor bubbles and conduct benchmarks studies with other groups from the SPP. - During the last funding period we derived the first continuum model for particle-covered interfaces, which we call the NSCHSPFC model. We will carefully examine this promising new approach which is the first model allowing long-time simulations of two-phase flows with interfacial nano-particles. As a further validation we will compare simulation results to experiments from R. Miller*. Using our advanced time integration and parallelization techniques will allow simulations of exciting real-world scenarios, from particle-induced surface viscosity (with A.Voigt*) to interface evolution of biological cells.

• DFG Programme: Priority Programmes
• Subproject of: SPP 1506: Transport Processes at Fluidic Interfaces