When astrophysical jets were discovered one hundred years ago, the field of numerical simulations did not yet exit. Since arrival programmable computers though, have increasingly become an indispensable tool for dealing with “tough nut” problems which involve complex dynamic and non-linear phenomena. Astrophysical are ideal example such a tough nut, where multi-scale plasma physics, radiative n...

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...

We study numerically the spatial properties of relaxation clusters in a two dimensional sandpile automaton with dynamic rules depending stochastically on a parameter p, which models the eeects of static friction. In the limiting cases p = 1 and p = 0 the model reduces to the critical height model and critical slope model, respectively. At p = p c , a continuous phase transition occurs to the st...

A 1D loop radiative hydrodynamic model that incorporates the effects of gravitational stratification, heat conduction, radiative losses, external heat input, presence of helium, and Braginskii viscosity is used to simulate elementary flare loops. The physical parameters for the input are taken from observations of the Bastille-Day flare of 2000 July 14. The present analysis shows that: a) the o...

enhanced oil recovery using nitrogen injection is a commonly applied method for pressuremaintenance in conventional reservoirs. numerical simulations can be practiced for the prediction ofa reservoir performance in the course of injection process; however, a detailed simulation might takeup enormous computer processing time. in such cases, a simple statistical model may be a goodapproach to the...

In this work, cold bulge forming of an Aluminium-Magnesium (Al-Mg) sheet with a solid bulging medium is performed experimentally and numerically.  Mechanical properties and thickness variations of Al-Mg sheet are evaluated before and after the forming process.  The results indicated that the Al-Mg sheet has taken the desired shape without necking using the cold bulge forming process.  Also, the...