Convection in binary fluid mixtures. II. Localized traveling waves

Spatially localized states in Marangoni convection in binary mixtures

Two-dimensional Marangoni convection in binary mixtures is studied in periodic domains with large spatial period in the horizontal. For negative Soret coefficients convection may set in via growing oscillations which evolve into standing waves. With increasing amplitude these waves undergo a transition to traveling waves, and then to more complex waveforms. Out of this state emerge stable stati...

Traveling-Wave Phase Boundaries in Compressible Binary Fluid Mixtures

Roll convection of binary fluid mixtures in porous media

We investigate theoretically the nonlinear state of ideal straight rolls in the Rayleigh– Bénard system of a fluid layer heated from below with a porous medium using a Galerkin method. Applying the Oberbeck–Boussinesq approximation, binary mixtures with positive separation ratio are studied and compared with one-component fluids. Our results for the structural properties of roll convection rese...

Convection in binary fluid mixtures with modulated heating.

The response behavior of strongly nonlinear binary fluid convection to temporal modulation of the heating is investigated for the case of a negative Soret coupling between temperature and concentration gradients. Finite difference numerical simulations are performed for ethanol-water parameters subject to realistic boundary conditions. Traveling waves with modulated amplitudes and phase velocit...

Localized waves without the existence of extended waves: oscillatory convection of binary mixtures with strong soret effect.

Spatially confined solutions of traveling convection rolls are determined numerically for binary mixtures such as ethanol-water. The appropriate field equations are solved in a vertical cross section of the rolls perpendicular to their axes subject to realistic horizontal boundary conditions. The localized convective states are stably and robustly sustained by strongly nonlinear mixing and comp...