A CERTIFIED REDUCED BASIS METHOD FOR THE FOKKER-PLANCK EQUATION OF DILUTE POLYMERIC FLUIDS: FENE DUMBBELLS IN EXTENSIONAL FLOW

In this paper we present a reduced basis method for the parametrized Fokker-Planck equation associated with evolution of finitely extensible nonlinear elastic (FENE) dumbbells in a Newtonian solvent for a (prescribed) extensional macroscale flow. We apply a proper orthogonal decomposition (POD)-greedy sampling procedure for the stable identification of optimal reduced basis spaces, and we develop a rigorous finite-time a posteriori bound for the error in the reduced basis prediction of the two outputs of interest-the optical anisotropy and the first normal stress difference. We present numerical results for stress-conformation hysteresis as a function of Weissenberg number and final time that demonstrate the rapid convergence of the reduced basis approximation and the effectiveness of the a posteriori error bounds.