Moffatt eddies in a rectangular channel

A detailed analysis of the fluid flow in a rectangular channel is performed by combining numerical and analytical methods. While finite element analysis numerical models are used to extract the transversal velocity field, an analytical model in the limit of zero Reynolds numbers is used to determine the longitudinal component of the fluid velocities. The high resolution 3D model developed for the fluid flow in channels with aspect ratios (i.e. depth/width) ranging from 1 to 0.1, allows the identification of the position and extent of Moffatt eddies that impede the fluid mixing through the entire channel. Implications for polymer processing with extruders will be presented.