  We present mesoscale numerical simulations based on the coupling of the
fluctuating lattice Boltzmann method (FLBM) for multicomponent systems with a
wetted finite-size particle model. This newly coupled methodologies are used to
study the motion of a spherical particle driven by a constant body force in a
confined channel with a fixed square cross-section. The channel is filled with
a mixture of two liquids under the effect of thermal fluctuations. After some
validations steps in absence of 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 settling velocity is quantitatively assessed, especially in comparison to
unconfined situations. Results show that the expected effects of confinement
are very well captured by the numerical simulations, wherein the 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 proposed methodology in
highlighting the effects of confinement on the motion of particles in presence
of thermal fluctuations.
