Turbulent Suspension Flows in Porous-Walled Duct Using Immersed Boundary Method

In this study, we employ Direct Numerical Simulations (DNS) combined with an immersed boundary method (IBM) to investigate the turbulent suspension flow of non-Brownian, non-colloidal, neutrally buoyant, rigid spherical particles in a duct with porous walls on all sides. We consider particle volume fractions (Φ_b​) ranging from 0 to 20%, and the particles interact with but do not enter the porous layers. The porosity is constant at 0.6 while the permeability is varying. Our primary objective is to analyze how varying the permeability of the porous layers affects the dynamics of the suspension particles within a turbulent duct flow. The duct geometry leads to the formation of vorticities along the sides of the duct, which significantly influence the flow dynamics. On the other hand, increasing the particle volume fractions greatly enhances the turbulence activities throughout the duct. In addition, as wall permeability increases, the streamwise velocity intensity near the interface also rises, indicating that the slip velocity increases. This research provides insights into optimizing the design and operation of systems relevant to various engineering applications, such as filtration systems and biomedical flows.