Lattice Boltzmann simulations of homogeneous shear turbulence laden with finite-size particles

As a powerful tool to investigate turbulent flows laden with finite-size particles, the lattice Boltzmann method (LBM)'s capability to contribute to a particle-resolved simulation of particle-laden homogeneous shear turbulence (HST) has yet to be realized. To capture the turbulence-particle interactions more accurately, the interpolated bounce-back schemes combined with the momentum-exchange method that possesses second-order accuracy are adopted to treat the no-slip condition on particle surfaces and compute the hydrodynamic force/torque. However, this choice brings extra difficulties in enforcing the shear periodic boundaries due to the absence of fluid information in solid regions. The present study resolves these difficulties by designing a scheme to construct the distribution functions in the particle gaps based on the lubrication theory and an algorithm for the "refilling" process near the shear periodic boundaries. With these developments, a direct numerical simulation of particle laden HST is achieved with LBM. The turbulence modulation effects induced by particles are briefly discussed.