Numerical modeling of the dynamics of nano- and microparticles at or close to an interface between two immiscible fluids based on a particle method
Final Report Abstract
In brief, the main results of the project are Inclusion of static and dynamic wetting phenomenainto a mesh-free particle code; development and validation of a mesh-free particle code for the Landau LifshitzNavier-Stokesequations; modelling and numerical simulation of the interaction of a rigid body with a compressible and incompressible fluctuating fluid; modelling and numerical simulation of the interaction of a rigid body with a rarefied gas; development and numerical investigation of a multi-scale mesh-free method for interacting particle systems; the structure of the EDL in the vicinity of a three-phase contact line has been computed; the influence of the EDL on the observed wetting angle of an electrolyte on a solid and the corresponding contribution of the EDL to the line tension have been quantified; the EDL structure around a spherical particle attached to a fluid interface has been computed; analytical expressions for the dynamic interface deformation due to a particle moving along a fluid interface and the particle tilt angle have been obtained for the case of large viscosity contrast between the fluids; the corresponding dynamic capillary interaction between two close-by particles moving along a fluid interface has been quantified; the low-Reynolds number drag force of a spherical particle attached to a fluid interface and moving along it has been computed for the case of large viscosity contrast between the fluids. Particles at fluid interfaces constitute a research area that has received increasing attention in the past few years. The analytical results obtained in the framework of this projects are relevant in a number of different areas. Examples are pickering emulsions, liquid marbles or flotation processes for which a better understanding of static and dynamic effects due to particles attached to fluid interfaces are of fundamental importance. On the one hand, we were able to provide closed-form expressions referring to phenomena that have been known before, such as the influence of EDLs on the observed contact angle of an electrolyte wetting a solid. On the other hand, we could uncover novel phenomena that the scientific community has not been aware of before, such as the deformation of the fluid interface by a moving particle and the corresponding dynamic capillary particle-particle interaction.
Publications
- Electric-double-layer structure close to the three-phase contact line in an electrolyte wetting a solid substrate, Physical Review E 86 (2012), 022601
A. Dörr and S. Hardt
(See online at https://doi.org/10.1103/PhysRevE.86.022601) - Meshfree method for fluctuating hydrodynamics, Math. Comput. 82(11) (2012), 2157-2166
A. Pandey, A. Klar, S. Tiwari
(See online at https://doi.org/10.1016/j.matcom.2012.06.002) - A multi-scale mesh-free method for macroscopic approximations of interacting particle systems, SIAM Multiscale Mod. Sim. 12No. 3(2014),1167-1192
A. Klar, S. Tiwari
(See online at https://doi.org/10.1137/130945788) - Line tension and reduction of apparent contact angle associated with electric double layers, Physics of Fluids 26 (2014), 082105
A. Dörr and S. Hardt
(See online at https://doi.org/10.1063/1.4892621) - Driven particles at fluid interfaces acting as capillary dipoles, Journal of Fluid Mechanics 770 (2015), 5–26
A. Dörr and S. Hardt
(See online at https://doi.org/10.1017/jfm.2015.129) - Numerical simulation of a rigid body in rarefied gas, J. Comput. Phys. 292 (2015), 239-252
S. Shrestha, S. Tiwari, A. Klar, S. Hardt
- Brownian dynamics of rigid particles in an incompressible fluctuating fluid by a mesh-free method, Comput. Fluids 127 (2016), 174-181
A. Pandey, S. Hardt, A. Klar, S. Tiwari
(See online at https://doi.org/10.1016/j.compfluid.2016.01.003) - Drag and diffusion coefficients of a spherical particle attached to a fluid interface, Journal of Fluid Mechanics 790 (2016), 607–618
A. Dörr, S. Hardt, H. Masoud and H. A. Stone
(See online at https://doi.org/10.1017/jfm.2016.41) - Numerical simulation of wetting phenomena by a mesh-free particle method, J. Comp. Appl. Math.292 (2016), 469-485
S. Tiwari, A. Klar, S. Hardt
(See online at https://doi.org/10.1016/j.cam.2015.07.021)
