Semiconvection: numerical simulations

Semiconvection: numerical simulations

A grid of numerical simulations of double-diffusive convection is presented for the astrophysical case where viscosity (Prandtl number Pr) and solute diffusivity (Lewis number Le) are much smaller than the thermal diffusivity. As in laboratory and geophysical cases convection takes place in a layered form. The proper translation between subsonic flows in a stellar interior and an incompressible...

Semiconvection: theory

A model is developed for the transport of heat and solute in a system of double-diffusive layers under astrophysical conditions (viscosity and solute diffusivity low compared with the thermal diffusivity). The process of formation of the layers is not part of the model but, as observed in geophysical and laboratory settings, is assumed to be fast compared to the life time of the semiconvective ...

Layer Formation in Semiconvection

Layer formation in a thermally destabilized fluid with stable density gradient has been observed in laboratory experiments and has been proposed as a mechanism for mixing molecular weight in late stages of stellar evolution in regions which are unstable to semiconvection. It is not yet known whether such layers can exist in a very low viscosity fluid: this work undertakes to address that questi...

NUMERICAL SIMULATIONS OF THE PHASE TRANSITIONS IN CLUSTERS

We have studied the phase transitions in atomic clusters by molecular dynamics simulation, assuming Lennard-Jones interatomic pair potential. Calculations are performed by DAP parallel computer. The results are analyzed by simulating their orientational distribution plots (dot-plot), and neutron diffraction patterns. It is shown that all the main features of the bulk phase transitions are e...

TOkamaks and NUmerical Simulations