Two-way coupling of FENE dumbbells with a turbulent shear flow

Physics – Fluid Dynamics

Scientific paper

Rate now

  [ 0.00 ] – not rated yet Voters 0   Comments 0

Details

20 pages, 10 Postscript figures (Figures 5 and 10 in reduced quality)

Scientific paper

10.1063/1.2735562

We present numerical studies for finitely extensible nonlinear elastic (FENE) dumbbells which are dispersed in a turbulent plane shear flow at moderate Reynolds number. The polymer ensemble is described on the mesoscopic level by a set of stochastic ordinary differential equations with Brownian noise. The dynamics of the Newtonian solvent is determined by the Navier-Stokes equations. Momentum transfer of the dumbbells with the solvent is implemented by an additional volume forcing term in the Navier-Stokes equations, such that both components of the resulting viscoelastic fluid are connected by a two-way coupling. The dynamics of the dumbbells is given then by Newton's second law of motion including small inertia effects. We investigate the dynamics of the flow for different degrees of dumbbell elasticity and inertia, as given by Weissenberg and Stokes numbers, respectively. For the parameters accessible in our study, the magnitude of the feedback of the polymers on the macroscopic properties of turbulence remains small as quantified by the global energy budget and the Reynolds stresses. A reduction of the turbulent drag by up to 20% is observed for the larger particle inertia. The angular statistics of the dumbbells shows an increasing alignment with the mean flow direction for both, increasing elasticity and inertia. This goes in line with a growing asymmetry of the probability density function of the transverse derivative of the streamwise turbulent velocity component. We find that dumbbells get stretched referentially in regions where vortex stretching or bi-axial strain dominate the local dynamics and topology of the velocity gradient tensor.

No associations

LandOfFree

Say what you really think

Search LandOfFree.com for scientists and scientific papers. Rate them and share your experience with other people.

Rating

Two-way coupling of FENE dumbbells with a turbulent shear flow does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Two-way coupling of FENE dumbbells with a turbulent shear flow, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Two-way coupling of FENE dumbbells with a turbulent shear flow will most certainly appreciate the feedback.

Rate now

     

Profile ID: LFWR-SCP-O-207742

  Search
All data on this website is collected from public sources. Our data reflects the most accurate information available at the time of publication.