2019 

Xiao Xue; Luca Biferale; Mauro Sbragaglia; Federico Toschi Particle settling in a fluctuating multicomponent fluid under confinement Journal Article arXiv, 2019, (12pages, 7 figures). Abstract  BibTeX  Tags: condmat.soft, physics.compph, physics.fludyn @article{d03238a0027f4132ad45a1d7327e35d7, title = {Particle settling in a fluctuating multicomponent fluid under confinement}, author = {Xiao Xue and Luca Biferale and Mauro Sbragaglia and Federico Toschi}, year = {2019}, date = {20190101}, journal = {arXiv}, publisher = {Cornell University Library}, abstract = {We study the motion of a spherical particle driven by a constant volume force in a confined channel with a fixed square crosssection. The channel is filled with a mixture of two liquids under the effect of thermal fluctuations. We use the lattice Boltzmann method to simulate a fluctuating multicomponent fluid in the mixedphase, and particlefluid interactions are tuned to reproduce different wetting properties at the particle surface. The numerical setup is first validated in the absence of thermal fluctuations; to this aim, we quantitatively compute the drift velocity at changing the particle radius and compare it with previous experimental and numerical data. In the presence of thermal fluctuations, we study the fluctuations in the particle's velocity at changing thermal energy, applied force, particle size, and particle wettability. The importance of fluctuations with respect to the mean drift velocity is quantitatively assessed, especially in comparison to unconfined situations. Results show that confinement strongly enhances the importance of velocity fluctuations, which can be one order of magnitude larger than what expected in unconfined domains. The observed findings underscore the versatility of the lattice Boltzmann simulations in concrete applications involving the motion of colloidal particles in a highly confined environment in the presence of thermal fluctuations.}, note = {12pages, 7 figures}, keywords = {condmat.soft, physics.compph, physics.fludyn}, pubstate = {published}, tppubtype = {article} } We study the motion of a spherical particle driven by a constant volume force in a confined channel with a fixed square crosssection. The channel is filled with a mixture of two liquids under the effect of thermal fluctuations. We use the lattice Boltzmann method to simulate a fluctuating multicomponent fluid in the mixedphase, and particlefluid interactions are tuned to reproduce different wetting properties at the particle surface. The numerical setup is first validated in the absence of thermal fluctuations; to this aim, we quantitatively compute the drift velocity at changing the particle radius and compare it with previous experimental and numerical data. In the presence of thermal fluctuations, we study the fluctuations in the particle's velocity at changing thermal energy, applied force, particle size, and particle wettability. The importance of fluctuations with respect to the mean drift velocity is quantitatively assessed, especially in comparison to unconfined situations. Results show that confinement strongly enhances the importance of velocity fluctuations, which can be one order of magnitude larger than what expected in unconfined domains. The observed findings underscore the versatility of the lattice Boltzmann simulations in concrete applications involving the motion of colloidal particles in a highly confined environment in the presence of thermal fluctuations. 
publications
2019 

Particle settling in a fluctuating multicomponent fluid under confinement Journal Article arXiv, 2019, (12pages, 7 figures). 