A numerical modeling study on the impact of particle concentration on the particle sorting in spiral channels

This work investigates the influence of concentration on the separation of microparticles in spiral microchannels. Using numerical modeling, we study the impact of the particle concentration on fluid flow pattern, particle trajectory, focusing resolution, and focusing time. Immersed boundary method and a numerical solver are developed in the OpenFOAM framework for modeling of particle motion. Modeling for different particle concentration in both rectangular and trapezoidal spiral channels is conducted to elucidate the particle focusing and separation efficiency in the spiral channels with a large number of particles. The detailed numerical modeling results clarify the configuration of Dean flow with multiple particles, the interaction within the particle cloud, and the impact of particle concentration on the focusing time and sorting process.