Comparison of low amplitude oscillatory shear in experimental and computational studies of model foams

Details Comparison of low amplitude oscillatory shear in experimental and computational studies of model foams Comparison of low amplitude oscillatory shear in experimental and computational studies of model foams

2008-07-29

arxiv.org/abs/0807.4743v2

Phys. Rev. E 79, 041405 (2009)

Physics

Condensed Matter

Soft Condensed Matter

Scientific paper

10.1103/PhysRevE.79.041405

A fundamental difference between fluids and solids is their response to applied shear. Solids possess static shear moduli, while fluids do not. Complex fluids such as foams display an intermediate response to shear with nontrivial frequency-dependent shear moduli. In this manuscript, we conduct coordinated experiments and numerical simulations of model foams subjected to boundary-driven oscillatory, planar shear. Our studies are performed on bubble rafts (experiments) and the bubble model (simulations) in 2D. We focus on the low-amplitude flow regime in which T1 bubble rearrangement events do not occur, yet the system transitions from solid- to liquid-like behavior as the driving frequency is increased. In both simulations and experiments, we observe two distinct flow regimes. At low frequencies $\omega$, the velocity profile of the bubbles increases linearly with distance from the stationary wall, and there is a nonzero total phase shift between the moving boundary and interior bubbles. In this frequency regime, the total phase shift scales as a power-law $\Delta \sim \omega^n$ with $n \approx 3$. In contrast, for frequencies above a crossover frequency $\omega > \omega_{p}$, the total phase shift $\Delta$ scales linearly with the driving frequency. At even higher frequencies above a characteristic frequency $\omega_{nl} > \omega_{p}$, the velocity profile changes from linear to nonlinear. We fully characterize this transition from solid- to liquid-like flow behavior in both the simulations and experiments, and find qualitative and quantitative agreement for the characteristic frequencies.

Affiliated with

Also associated with

No associations

Rating

Comparison of low amplitude oscillatory shear in experimental and computational studies of model foams 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 Comparison of low amplitude oscillatory shear in experimental and computational studies of model foams, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Comparison of low amplitude oscillatory shear in experimental and computational studies of model foams will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-258888