Numerical investigation of multistability in the unstable flow of a polymer solution through porous media

The accumulation of stresses as polymeric chains cross successive pores creates streaks of high polymeric stress. Highly stretched polymeric chains in the regions of high polymeric stress resist the flow crossing these streaks, leading to eddy formation in the different regions of the pores. Multiple distinct unstable flow structures occur inside the pore above a critical Weissenberg number.