Fourier decomposition of polymer orientation in large-amplitude oscillatory shear flow

• DOI: 10.1063/1.4914411
• Publication Date: 2015-03-19T17:00:38Z
• Authors: A. J. Giacomin; P. H. Gilbert; A. M. Schmalzer
• Keywords: Weissenberg number

In our previous work, we explored the dynamics of a dilute suspension rigid dumbbells as model for polymeric liquids in large-amplitude oscillatory shear flow, flow experiment that has gained significant following recent years. We chose since these are simplest molecular to give higher harmonics components stress response. derived expression dumbbell orientation distribution, and then used this function calculate response, normal difference responses flow. paper, deepen understanding polymer motion underlying by decomposing distribution into its first five Fourier (the zeroth, first, second, third, fourth harmonics). use three-dimensional images explore each harmonic motion. Our analysis includes three most important cases: (i) nonlinear steady (where Deborah number λω is zero Weissenberg λγ̇0 above unity), (ii) viscoelasticity both exceed (iii) linear exceeds unity where approaches zero). learn spherical viscoelastic regime, otherwise tilted peanut-shaped. find peanut-shaping mainly caused zeroth harmonic, tilting, second. The make only slight contributions overall