CiteULike: dchen's foam

Instabilities in liquid foams

D Weaire — 2008-06-20T22:24:37-00:00

Soft Matter, 2007, 3, 47 - 57, DOI: 10.1039/b608466b

Instabilities play a central role in the physics of foams. Some that change the topology of a dry foam are indicated by the laws promulgated by Plateau in his 1873 book. Their occurrence is less clearly predictable in wet foams. Various other instabilities are related to gravitational loading and gas compressibility. We gather up many examples as a guide to future research and identify problems that remain, including what we call pre-emptive instabilities, which occur before they are expected on the basis of Plateau's laws.

Rheology of Steady-State Draining Foams

Raenell Soller — 2008-06-06T18:00:34-00:00

Physical Review Letters, Vol. 100, No. 20. (2008)

We developed the foam drainage rheology technique in order to perform rheological measurements of aqueous foams at a set liquid fraction and fixed bubble radius R without the usual difficulties associated with fluid drainage and bubble coarsening. The shear stress exhibits a power-law dependence on strain-rate, ~n where n0.2. The stress exhibits an inverse dependence on liquid content, ~(1+h)-1, where h=(10) exhibits a diminishing logarithmic trend with . We propose a model based upon film shearing as the dominant source of viscous dissipation.

Increasing Magnetoplasticity in Polycrystalline Ni-Mn-Ga by Reducing Internal Constraints through Porosity

Yuttanant Boonyongmaneerat — 2008-05-04T00:05:33-00:00

Physical Review Letters, Vol. 99, No. 24. (2007)

Foams with 55% and 76% open porosity were produced from a Ni-Mn-Ga magnetic shape-memory alloy by replication casting. These polycrystalline martensitic foams display a fully reversible magnetic-field-induced strain of up to 0.115% without bias stress, which is about 50 times larger than nonporous, fine-grained Ni-Mn-Ga. This very large improvement is attributed to the bamboolike structure of grains in the foam struts which, due to reduced internal constraints, deform by magnetic-field-induced twinning more easily than equiaxed grains in nonporous Ni-Mn-Ga.

Velocity fluctuations in a steadily sheared model foam

Ian Ono — 2008-04-29T00:58:30-00:00

Physical Review E, Vol. 67, No. 6. (18 June 2003), 061503.

Nonlinear stress and fluctuation dynamics of sheared disordered wet foam

Ethan Pratt — 2008-04-29T00:41:34-00:00

Physical Review E, Vol. 67, No. 5. (May 2003), 051402.

Local Stress Relaxation and Shear Banding in a Dry Foam under Shear

Alexandre Kabla — 2008-04-28T16:00:58-00:00

Physical Review Letters, Vol. 90, No. 25. (27 June 2003), 258303.

Foam in a two-dimensional Couette shear: a local measurement of bubble deformation

D1 — 2008-04-28T14:45:29-00:00

243 c 2005 Cambridge University Press J. Fluid Mech. (2005), vol. 532, pp. 243–267.

Viscous instabilities in flowing foams: a Cellular Potts Model approach

Soma Sanyal — 2006-10-18T18:43:28-00:00

J. Stat. Mech., Vol. 2006, No. 10. (October 2006), P10008.

Slow dynamics in glasses, gels and foams

Luca Cipelletti — 2008-04-28T14:27:59-00:00

Current Opinion in Colloid & Interface Science, Vol. 7, No. 3-4. (August 2002), pp. 228-234.

Slow dynamics and aging effects in disordered, out-of-equilibrium systems are a rich and fascinating topic, yet still poorly understood. Recent developments in light scattering methods, such as the multispeckle technique, combined with new theoretical approaches that underline the analogies between different glassy materials are bringing a better understanding of these phenomena.

FOAM FLOWS

Andrew Kraynik — 2008-04-28T13:59:32-00:00

Ann.Rev. Fluid Mech. 988.20 : 325-57

Structure of Random Foam

Andrew Kraynik — 2008-04-28T13:55:47-00:00

Physical Review Letters, Vol. 93, No. 20. (November 2004), 208301.

The rheology of two-dimensional foams

Simon Cox — 2008-04-27T00:23:47-00:00

Rheologica Acta, Vol. 43, No. 5. (1 November 2004), pp. 442-448.

We survey simulations of two-dimensional flowing foam inspired by recent illuminating experiments. We also describe the viscous froth model, an effective tool for such simulations, which accurately represents the detailed structure of the foam and includes a linear drag force.

Foam Mechanics at the Bubble Scale

DJ Durian — 2007-09-27T03:41:32-00:00

Physical Review Letters, Vol. 75, No. 26. (25 December 1995), 4780.

By focusing on entire bubbles rather than films or vertices; a simple model is proposed for the deformation and flow of foam in which dimensionality; polydispersity; and liquid content can easily be varied. Simulation results are presented for the linear elastic properties as a function of bubble volume fraction; showing a melting transition where the static shear modulus vanishes and the relaxation time scale peaks. Results are also presented for shear stress versus strain rate; showing intermittent flow via avalanchelike topological rearrangements and Bingham-plastic behavior.

Deformation and Flow of a Two-Dimensional Foam under Continuous Shear

G Debrégeas — 2008-04-26T23:52:31-00:00

Physical Review Letters, Vol. 87, No. 17. (October 2001), 178305.

Shear-Induced Stress Relaxation in a Two-Dimensional Wet Foam

John Lauridsen — 2008-04-26T22:16:37-00:00

Physical Review Letters, Vol. 89, No. 9. (2002), 098303.

Shear-Induced Changes in Two-Dimensional Foam

Abd — 2008-04-26T22:15:30-00:00

Physical Review Letters, Vol. 82, No. 12. (22 March 1999), 2610.

Two-Dimensional Foam Rheology with Viscous Drag

E Janiaud — 2008-04-26T22:13:18-00:00

Physical Review Letters, Vol. 97, No. 3. (2006)

We formulate and apply a continuum model that incorporates elasticity, yield stress, plasticity, and viscous drag. It is motivated by the two-dimensional foam rheology experiments of Debregeas et al. [Phys. Rev. Lett. 87, 178305 (2001)] and Wang et al. [Phys. Rev. E 73, 031401 (2006)], and is successful in exhibiting their principal features, which are an exponentially decaying velocity profile and strain localization. Transient effects are also identified.

An elastic, plastic, viscous model for slow shear of a liquid foam

P Marmottant — 2008-04-18T01:30:45-00:00

The European Physical Journal E - Soft Matter, Vol. 23, No. 4. (2007), pp. 337-347.

Abstract. We suggest a scalar model for deformation and flow of an amorphous material such as a foam or an emulsion. To describe elastic, plastic and viscous behaviours, we use three scalar variables: elastic deformation, plastic deformation rate and total deformation rate; and three material-specific parameters: shear modulus, yield deformation and viscosity. We obtain equations valid for different types of deformations and flows slower than the relaxation rate towards mechanical equilibrium. In particular, they are valid both in transient or steady flow regimes, even at large elastic deformation. We discuss why viscosity can be relevant even in this slow shear (often called “quasi-static”) limit. Predictions of the storage and loss moduli agree with the experimental literature, and explain with simple arguments the non-linear large amplitude trends.

Bubble Raft Model for an Amorphous Alloy

AW Simpson — 2008-04-16T21:51:05-00:00

Nature, Vol. 237, No. 5354. (June 1972), pp. 320-322.

Diffusive Liquid Propagation in Porous and Elastic Materials: The Case of Foams under Microgravity Conditions

Saint Jalmes — 2008-03-19T16:58:14-00:00

Physical Review Letters, Vol. 98, No. 5. (2007)

We report the results of fluid transport experiments in aqueous foams under microgravity. Using optical and electrical methods, the capillary motion of the foam fluid and the local liquid fractions are monitored. We show that foams can be continuously wetted up to high liquid fractions (~0.3), without any bubble motion instabilities. Data are compared to drainage models: For liquid fractions above 0.2, discrepancies are found and identified. These new results on foam hydrodynamics and structure can be useful for other poroelastic materials, such as plants and biological tissues.

Experimental Growth Law for Bubbles in a Moderately “Wet” 3D Liquid Foam

Jérôme Lambert — 2008-03-18T21:26:37-00:00

Physical Review Letters, Vol. 99, No. 5. (2007)

We used x-ray tomography to characterize the geometry of all bubbles in a liquid foam of average liquid fraction l17% and to follow their evolution, measuring the normalized growth rate =V-1/3 for 7000 bubbles. While does not depend only on the number of faces of a bubble, its average over f-faced bubbles scales as Gf~f-f0 for large f's at all times. We discuss the dispersion of and the influence of V and l on .

Diffusion and Relaxation Dynamics in Cluster Crystals

Angel Moreno — 2008-03-18T20:36:27-00:00

Physical Review Letters, Vol. 99, No. 10. (2007)

For a large class of fluids exhibiting ultrasoft bounded pair potentials, particles form crystals consisting of clusters located in the lattice sites, with a density-independent lattice constant. Here we present an investigation on the dynamic features of a representative example of this class. It is found that particles can diffuse between lattice sites, maintaining the lattice structure, through an activated hopping mechanism. This feature yields finite values for the diffusivity and full relaxation of density correlation functions. Simulations suggest the existence of a localization transition which is avoided by hopping and a dynamic decoupling between self- and collective correlations.

Rigidity Percolation in Particle-Laden Foams

Sylvie Addad — 2008-03-18T19:16:27-00:00

Physical Review Letters, Vol. 99, No. 16. (2007)

We study the viscoelastic behavior of aqueous foam mixed with solid noncolloidal particles. We show that adding a tiny amount of grains can enhance the elastic and loss shear moduli by more than 1 order of magnitude. The scaling of these moduli with solid volume fraction is in qualitative agreement with that predicted by an effective-medium rigidity percolation model. We present a simple model, based on capillary attraction, to explain the particle-size dependence of the threshold.

Mechanical probing of liquid foam ageing

I Cantat — 2006-08-11T13:48:17-00:00

Journal of Physics: Condensed Matter, Vol. 17, No. 45. (2005), pp. S3455-S3461.

We present experimental results on the Stokes experiment performed in a 3D dry liquid foam. The system is used as a rheometric tool: from the force exerted on a 1~cm glass bead, plunged at controlled velocity in the foam in a quasi-static regime, local foam properties are probed around the sphere. With this original and simple technique, we show the possibility of measuring the foam shear modulus, the gravity drainage rate and the evolution of the bubble size during coarsening.