Localized traveling pulses in natural doubly diffusive convection

David Lo Jacono (1) , Alain Bergeon (1) , Edgar Knobloch (2)

1 IMFT - Institut de mécanique des fluides de Toulouse
2 LBNL - Lawrence Berkeley National Laboratory [Berkeley]

Two-dimensional natural doubly diffusive convection in a vertical slot driven by an imposed temperature difference in the horizontal is studied using numerical continuation and direct numerical simulation. Two cases are considered and compared. In the first a concentration difference that balances thermal buoyancy is imposed in the horizontal and stationary localized structures are found to be organized in a standard snakes-and-ladders bifurcation diagram. Disconnected branches of traveling pulses TPn consisting of n, n = 1,2, . . . , corotating cells are identified and shown to accumulate on a tertiary branch of traveling waves. With Robin or mixed concentration boundary conditions on one wall all localized states travel and the hitherto stationary localized states may connect up with the traveling pulses. The stability of the TPn states is determined and unstable TPn shown to evolve into spatio-temporal chaos. The calculations are done with no-slip boundary conditions in the horizontal and periodic boundary conditions in the vertical.

Mots clés: Localised states; Doubly diffusion convection

Domaines: Mécanique des fluides [physics.class-ph]

David Lo Jacono, Alain Bergeon, Edgar Knobloch. Localized traveling pulses in natural doubly diffusive convection. Physical Review Fluids, 2017, 2 (9), pp.093501. ⟨10.1103/PhysRevFluids.2.093501⟩. ⟨hal-01619713⟩