Numerical study of sand particles transporting in the atmospheric Ekman boundary layer

The Eulerian-Lagrangian two-phase direct numerical simulation is used to study the dynamics of sand particles transporting in the atmospheric Ekman boundary layer. The results reveal that the velocity of sand particles in the viscous and buffer layers can apparently be influenced by gravity. But nearly no evident difference is discovered in the turbulent region where the inertial force is dominant. Further evidence on the interaction between particle and vortex shows that gravity is not strong enough in our simulation to change their relationship even in the viscous force dominant layers. Sand particles exhibit apparent tendency to accumulate in the low vortex strength regions similar to the particle-laden homogenous isotropic turbulence.