We present a novel discretization method for nonlinear convection-diffusion equations and, in particular, for the compressible Navier-Stokes equations. The method is based on a Discontinuous Galerkin (DG) discretization for convection terms, and a Mixed method using H(div) spaces for the diffusive terms. Furthermore, hybridization is used to reduce the number of globally coupled degrees of free...

Linear stability analysis is performed for the onset of thermosolutal convection in a horizontal fluid layer with rigid-rigid boundaries. The temperature field between the walls of the fluid layer consists of two parts: a steady part and a time-dependent periodic part that oscillates with time. Only infinitesimal disturbances are considered. The effect of temperature modulation on the onset of ...

While the metallicity excess observed in the central stars of planetary systems is confirmed by all recent observations, the reason for this excess is still a subject of debate : is it primordial, is it the result of accretion or both? The basic argument against an accretion origin is related to the mass of the outer convective zones which varies by more than one order of magnitude among the co...

Entropy generation of double diffusive natural convection in a three dimensional differentially heated enclosure has been performed numerically. Vertical walls of enclosure are heated differentially and remaining walls are adiabatic. The obtained results were presented via iso-concentration, iso-temperatures, velocity vector projection, particle trajectories, velocity profiles, iso-entropy, loc...

One of the practical methods for examining stability and dynamical behaviour non-linear systems is weakly analysis. Time-varying gravitational acceleration triple-diffusive convection play a significant role in formation acceleration, inducing some dynamics industry. With an emphasis on natural Rayleigh–Bernard convection, more needed significance modulated field heat mass transfer due to tripl...

A numerical method is presented to solve a two-dimensional hyperbolic diffusion problem where is assumed that both convection and diffusion are responsible for flow motion. Since direct solutions based on implicit schemes for multidimensional problems are computa-tionally inefficient, we apply an alternating direction method which is second order accurate in time and space. The stability of the...

double-diffusive mixed convection in a lid-driven square enclosure filled with al2o3-water is numerically investigated. two-dimensional nonlinear governing equations are discretized using the control volume method and hybrid scheme. the equations are solved using simpler algorithm. the results are displayed in the form of streamlines, isotherms, and iso-concentrations when the richardson number...

This paper deals with the principle of groundwater pollution. The basic equation for pollution distribution is the diffusion equation. In the natural but also economical science different kinds of this equation are used. This work focuses on the convection-diffusion equation. Using this equation the diffusive behavior of the pollution influenced by a velocity field is described. Several approac...