Peeling of elastic sheet using complex fluids at low Reynolds numbers

We investigate the transient fluid structure interactions (FSIs) of a non-Newtonian fluid peeling a elastic  sheet at low Reynolds numbers (Re) .We express the rheology of the fluid through the simplified Phan-Thien-Tanner (sPTT) model. Invoking the lubrication approximation for fluid flow and modeling the structure as series of Hookean springs, we reduce the problem to that of a partial differential equation for the evolution of the deformed height in time and space. An order of magnitude analysis reveals two distinct regimes of peeling, based on the relative magnitude of the viscoelasticity and FSI parameters, further aided by similarity solutions. On inspecting the numerical solution, we infer that the non-Newtonian nature brings the system to a steady state faster in comparison to a Newtonian fluid. We explore this idea by investigating the dynamics of peeling actuated by purely shear thinning fluids. And therefore, we present the results for the peeling actuated by such generalized Newtonian fluids as well. To conclude, this study aims to afford to the experimentalist a system of knowledge to a priori delineate the peeling characteristics of a certain class of complex fluids.