Linear stability Analysis of Viscoelastic Flows

Abstract: The goal of present work is to investigate the instability of jet ow, mixing layer and Poiseuille ow of viscoelastic uids. According to Boeta et al: [4], small elastic eect in Kolmogorov ow will result in increasing critical Re for hydrodynamic instability, however, at high elasticity a new instability of elastic nature occurs even at vanishing Re. This thesis aims to test this result in jet and mixing layer. In addition, linear stability analysis (modal and non-modal) of viscoelastic Poiseuille ow is carried out to understand the elastic eects on the ows of both Oldroyd-B and FENE-P model uids. Energy analysis is used to reveal the instability mechanism.