Swinging and tumbling of elastic capsules in shear flow

Details Swinging and tumbling of elastic capsules in shear flow Swinging and tumbling of elastic capsules in shear flow

2007-09-17

arxiv.org/abs/0709.2610v2

Journal of Fluid Mechanics 605, 207-226 (2008)

Physics

Condensed Matter

Soft Condensed Matter

20 pages, 7 figures

Scientific paper

10.1017/S0022112008001493

The deformation of an elastic micro-capsule in an infinite shear flow is studied numerically using a spectral method. The shape of the capsule and the hydrodynamic flow field are expanded into smooth basis functions. Analytic expressions for the derivative of the basis functions permit the evaluation of elastic and hydrodynamic stresses and bending forces at specified grid points in the membrane. Compared to methods employing a triangulation scheme, this method has the advantage that the resulting capsule shapes are automatically smooth, and few modes are needed to describe the deformation accurately. Computations are performed for capsules both with spherical and ellipsoidal unstressed reference shape. Results for small deformations of initially spherical capsules coincide with analytic predictions. For initially ellipsoidal capsules, recent approximative theories predict stable oscillations of the tank-treading inclination angle, and a transition to tumbling at low shear rate. Both phenomena have also been observed experimentally. Using our numerical approach we could reproduce both the oscillations and the transition to tumbling. The full phase diagram for varying shear rate and viscosity ratio is explored. While the numerically obtained phase diagram qualitatively agrees with the theory, intermittent behaviour could not be observed within our simulation time. Our results suggest that initial tumbling motion is only transient in this region of the phase diagram.

Affiliated with

Also associated with

No associations

Rating

Swinging and tumbling of elastic capsules in 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 Swinging and tumbling of elastic capsules in shear flow, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Swinging and tumbling of elastic capsules in shear flow will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-378724