Near-surface rheology and hydrodynamic boundary condition of semi-dilute polymer solutions

Understanding confined flows of complex fluids requires simultaneous access to the mechanical behaviour of the liquid and the boundary condition at the interfaces. Here, we use evanescent wave microscopy to...

Assessment of the Hydrodynamic Boundary Condition at Open-Porous Interface Using Pore-Level Flow Simulations

In this paper, we follow the pore-level flow simulation approach to investigate fluid flow over an open-porous interface using the lattice Boltzmann method. As this approach does not require any specific treatment for the interface, its results can be used to evaluate the current macroscopic boundary conditions for the interface. The Beavers & Joseph boundary condition is evaluated and the value of slip coefficient is presented as a function of porosity of the porous region. Analytical solution of the velocity profile in the close vicinity of the interface is used to predict the penetration depth. The predicted numerical results for porous penetration depth are in excellent agreement with those predicted from the analytical solution.