Coarsening Dynamics of 2D Subaqueous Dunes

Fixation for coarsening dynamics in 2D slabs

We study zero-temperature Ising Glauber Dynamics, on 2D slabs of thickness k ≥ 2. In this model, ±1-valued spins at integer sites update according to majority vote dynamics with two opinions. We show that all spins reaches a final state (that is, the system fixates) for k = 2 under free boundary conditions and for k = 2 or 3 under periodic boundary conditions. For thicker slabs there are sites ...

Subaqueous Barchan dunes in turbulent shear flow. Part 2: Fluid flow

Heterogeneous dynamics of coarsening systems.

We show by means of experiments, theory, and simulations that the slow dynamics of coarsening systems displays dynamic heterogeneity similar to that observed in glass-forming systems. We measure dynamic heterogeneity via novel multipoint functions which quantify the emergence of dynamic, as opposed to static, correlations of fluctuations. Experiments are performed on a coarsening foam using tim...

A scaling law for aeolian dunes on Mars, Venus, Earth, and for subaqueous ripples

The linear stability analysis of the equations governing the evolution of a flat sand bed submitted to a turbulent shear flow predicts that the wavelength λ at which the bed destabilises to form dunes should scale with the drag length Ldrag = ρs ρf d. This scaling law is tested using existing and new measurements performed in water (subaqueous ripples), in air (aeolian dunes and fresh snow dune...

A scaling law for aeolian dunes on Mars, on Earth and subaqueous ripples

The linear stability analysis of equations governing the evolution of a flat sand bed submitted to a shearing flow predicts that the wavelength λ at which the bed destabilises to form dunes should scale with the drag length Ldrag = ρs ρf d. We tested this scaling law using measurements performed in water (subaqueous ripples), in air (aeolian dunes) and in the CO2 martian atmosphere (martian dun...