Acceleration Statistics of Finite-Size Particles in Turbulent Channel Flow in the Absence of Gravity

Abstract

The interaction between finite-size particles and turbulent channel flow in the absence of gravity is studied here by direct numerical simulation. The turbulent flow is resolved by an efficient Fourier Chebyshev method, coupled with a direct forcing method for particle tracking. For the volume fraction and particle size we studied here, the presence of particles decreases slightly the streamwise mean velocity in the near wall region. The velocity fluctuations in the vicinity of particles are dissipated more than generated by the presence of the wakes. According to the statistics of the fluid in the vicinity of particles, particles segregate in regions of low streamwise and spanwise r.m.s. velocity close to the wall. Moreover, between the region of maximum particle concentration and the wall, particles are swept by flow presenting high acceleration fluctuations.