The presence of an icy crust covering several satellites of the solar system (e.g. Europa, the jovian satellite) suggested us to accomplish the numerical simulation of the Rayleigh-Benard convection flow of a horizontal layer of mushy water, covered at the top by its own ice and immersed in a low gravity field. The phase transition occurring at the ice/mushy water interface, with release/absorp...

In this study, the effects of Prandtl number on the primary and secondary instability of the Rayleigh-Benard convection problem has been investigated using the lattice Boltzmann method. Two different cases as Pr=5.8 and 0.7 representing the fluid in liquid and gas conditions are examined. A body forces scheme of the lattice Boltzmann method was presented. Two types of boundary conditions in the...

Motivated by the observation of spiral patterns in a wide range of physical, chemical, and biological systems, we present an automated approach that aims at characterizing quantitatively spiral-like elements in complex stripe-like patterns. The approach provides the location of the spiral tip and the size of the spiral arms in terms of their arc length and their winding number. In addition, it ...

Eddy length scales, eddy velocity scales, and the amplitude of eddy fluxes in the mid-latitude troposphere are discussed, primarily from the qualitative perspective provided by studies of quasi-geostrophic turbulence. The utility of a diffusive picture for the near surface poleward flux of heat is emphasized, as is the extent to which a full closure theory for the troposphere, including the int...

The use of lattice gas (cellular automaton) models has recently been advocated as an interesting method for the simulat ion of fluid flow . Th ese automata are an idealizat ion of the real microscopic molecula r dynamics. We present a model derived from the hexagonal lat t ice gas ru les of Frisch Hasslacher and Pomea u (FHP) that incorporates buoyant forces and d iscusses its prope rt ies. We ...