Fully-resolved direct numerical simulations of particle motion in a turbulent channel flow with the lattice-Boltzmann method

•Effect of St on particle concentration profiles in a turbulent flow is studied.•Particles with low St exhibit a high concentration near the wall.•Particles with high St have a nearly uniform concentration profile.•Impact of Saffman lift and turborphoretic forces on particle motion is discussed. Particle-resolved direct numerical simulations (PR-DNS) of particle-laden turbulent flow in a channel are carried out to understand the effect of particle Stokes number (St) on their motion. The study focuses on particles which are larger than the Kolmogorov scale. The forces that impact this motion are factored into the discussion. The lattice-Boltzmann method (LBM) is employed for the simulations. The scheme employed is able to resolve the surface of the particle and a method is adopted to account for the exchange of momentum between the particles and fluid as the particles move on fixed lattices. The simulations show that particles with relatively lower St move preferentially toward the wall while those with higher St exhibit a relatively uniform concentration.