Numerical Simulation of two particles in a bended micro-channel

Abstract

Microfluidics has been widely utilized in various applications including biochemical analysis and medical diagnosis. As, from last decade particles separation and mixing in optimized micro channel through various modern techniques is an emerging field. A numerical investigation and parametric study have been developed for two micro-particles in a bended micro-channel using COMSOL Multiphysics 5.2. The focus of research is to identify the trajectories of particles and particle-particle gap with wide range of parametric diversities. There are three study setups developed for identifying and optimizing the range of particles’ position at inlet of micro-channel. For fluid domain, blood is considered with platelets, debris and white blood cells (WBCs) as micro particles. Initially, by varying the inlet gap between two particles in horizontal and vertical directions, the gap between particles is observed at outlet of micro-channel with finite range of flow rates from 0.8μl/min to 2.6 μl/min. Furthermore, the particle trajectories are plotted using Newtonian formulation combined with stokes drag law. One-way coupling is introduced for particle-fluid interaction in which effects of fluid on particles are considered. Dominant changes in particle-particle gap and trajectories of particles at bended portion and after bend of micro-channel are observed. A dimensionless parameter (є) which is a hydraulic diameter of micro-channel and length of channel after bended portion dependent number, defined for optimizing the particle-particle outlet gap for a set of inlet positions and velocities. Secondly, size base study is performed by considering average cell size of platelets, debris and white blood cells ranging from 2μm-12μm under same position and flow rate conditions. Finally, density base study is simulated for normal and cancerous white blood cells with same size and optimized range of velocity.