The Effect of Particles on The Dynamics of Fluid Flows Around an Obstacle

The two-way fluid-solid coupling model is developed to numerically study the effect of particles on the dynamics of fluid flows around an obstacle. Fluid with a large number of finite-sized particles flows around a large-sized obstacle, where randomly distributed particles flow into the domain at the same speed as the fluid, while the obstacle is fixed. The fluid flow is described by the Eulerian formalism, while the Lagrangian formalism is used for the particles and obstacle. Specifically, the discrete element method is applied to evaluate the motion of the particles and a fully-resolved direct numerical simulation of fluid-obstacle interactions is achieved by using the immersed boundary method. The results show that the introduction of particles changes the structure of the flow field where the vortex behind the obstacle sheds up and down alternately. The original regular vortex collapses due to the influence of particles on the fluid, and as the particle mass loading ratio increases, the intensity of the vortex increases.