Abstract
This research studies the single-phase fluid flow in a two-dimensional microfluidic cell focusing on particle trajectories to gain insight into the transport phenomenon in porous media. It evaluates the passing performance by calculating the trajectory of released particles through the cell. The study was performed on a microfluidic cell with a size of approximately 5 mm x 1.5 mm. COMSOL Multiphysics software was used to perform simulations. Fluid flow is governed by the Navier-Stokes equations, the laminar flow interface and the finite element method (FEM) were used to compute the fluid velocity and pressure fields within the cell domain. Six separate cases were considered: 1. constant injection velocity, 2. randomly varying velocity with the coefficient of variance (CV) of 1% and 0.5%, 3. Sine function with three different values of amplitude. The wall conditions were no-slip and bounce in the CFD Module and the Particle Tracing Module, respectively. Results were compared for the particle transmission probabilities, the velocity fields, pressure, longitudinal Lagrangian velocities/accelerations, and mean square displacement (MSD). The simulation with 0.5% randomly varying velocity and sine function with an amplitude of 5% had the highest value of transmission probability 0.785, and constant velocity had the lowest value of transmission probability 0.781. All six simulations had similar surface velocity field and pressure contour plots. Additionally, the MSD plots had similar trends as well, and the Fickian scaling was not reached during the simulation time. The dispersion was sub-diffusive and non-Fickian in all cases.