Dynamics of pairs and triplets of particles in a viscoelastic fluid flowing in a cylindrical channel

The three-particle dynamics is more complex. In a Newtonian liquid, the leftmost particle of the triplet approaches and slows down the middle one. Consequently, the rightmost particle separates, giving rise to a pair and an isolated particle. A similar scenario occurs for a viscoelastic liquid. In this case, however, depending on the initial configuration and the Deborah number, the particles forming the pair can subsequently approach or separate. In the latter case, the final configuration is the formation of three isolated particles.