We present a mesoscopic numerical solver for the constitutive equation of dilute polymer solutions, as described by Fokker–Planck bead-spring dumbbell models with linear spring forces, such Oldroyd-B, FENE-P (finitely extensible nonlinear elastic Peterlin closure), and C-FENE-P (charged FENE-P). The configuration density function is expanded into series Hermite polynomials, we show that only se...

We investigate the effects of helical swimmer shape (i.e., pitch angle and tail thickness) on swimming dynamics in a constant viscosity viscoelastic (Boger) fluid via combination particle tracking velocimetry, image velocimetry 3D simulations FENE-P model. The printed is actuated magnetic field using custom-built rotating Helmholtz coil. Our results indicate that increasing thickness enhances n...

In this talk, we present some joint work with current and former colleagues at Penn State (C. Liu, P. Yu and Y. Hyon) on moment closure approximations of multiscale complex fluid models. Moment closure not only provides a computationally feasible approach to simulate many multiscale phenomena but also offers insight to the understanding of the underlying physical processes. We will discuss some...

For many commonly used viscoelastic constitutive equations, it is well known that the limiting behavior of Oldroyd-B model. Here, we compare response simplified linear form Phan-Thien–Tanner model (“sPTT”) [Phan-Thien and Tanner, “A new equation derived from network theory,” J. Non-Newtonian Fluid Mech. 2, 353–365 (1977)] finitely extensible nonlinear elastic (“FENE”) dumbbell follows Peterlin ...

We present some analytical and numerical studies on the finite extendible nonlinear elasticity (FENE) model of polymeric fluids and its several moment-closure approximations. The well-posedness of the FENE model is established under the influence of a steady flow field. We further infer existence of long-time and steady-state solutions for purely symmetric or antisymmetric velocity gradients. T...

The effect of stress diffusivity is examined in both the Oldroyd-B and FENE-P models of a viscoelastic fluid in the low Reynolds (Stokes) limit for a 2D periodic time-dependent flow. A local analytic solution can be obtained when assuming a flow of the form u =Wi (x, y), whereWi is the Weissenberg number. In this case the width of the birefringent strand of the polymer stress scales with the ad...

Fluid dynamic simulations using the FENE-P model of polymer physics are compared to those an incompressible Newtonian fluid base case in order understand role elasticity formation vortices a 90° bend narrow channel. The analysis bridges flow behavior purely elastic and that fluid. We evaluated how four dimensionless numbers—Reynolds number (Re), Weissenberg (Wi), viscosity ratio (?), (El)—affec...

We present a study of the rheology and optical properties during the start-up of uniaxial extensional and shear flow for freely-draining, Kramers bead-rod chains using Brownian dynamics simulations. The viscous and elastic contributions to the polymer stress are unambiguously determined via methods developed in our previous publication [1]. The elastic contribution to the polymer stress is much...