The problem of hydrodynamic dispersion in non-Darcy free convection heat and mass transfer from vertical surface embedded in a porous medium has been presented. The Forchheimer extension is considered in the flow equations. The flow, temperature and concentration fields in Darcy and non-Darcy porous media are observed to be governed by complex interactions among the diffusion rate Le, buoyancy ...

In thermal convection, coherent flow structures emerge at high Rayleigh numbers as a result of intrinsic hydrodynamic instability and self-organization. They range from small-scale thermal plumes that are produced near both the top and the bottom boundaries to large-scale circulations across the entire convective volume. These flow structures exert viscous forces upon any boundary. Such forces ...

Explosive nucleosynthesis is a combination of the nuclear physics of thermonuclear reactions, and the hydrodynamics of the plasma in which the reactions occur. It depends upon the initial conditions—the stellar evolution up to the explosive instability, and the nature of the explosion mechanism. Some key issues for explosive nucleosynthesis are the interaction of burning with hydrodynamics, the...

The theory of diffusive particle acceleration explains the spectral properties of the cosmic rays below energies of ≃ 10 eV as produced at strong shocks in supernova remnants (SNR’s). To supply the observed flux of cosmic rays, a significant fraction of the energy released by a supernova has to be transfered to cosmic rays. The key to the question of the efficiency of SNR’s in producing cosmic ...

A three-dimensional boundary layer solution is presented to study the effect of magneto-hydrodynamic with variable viscosity on natural convection in the vicinity of an axisymmetric stagnation point on heated vertical surfaces saturated in porous medium. The fluid viscosity is assumed to vary as a linear function of temperature. The governing partial differential equations for the flow and heat...

Context. Red supergiant stars represent a key phase in the evolution of massive stars. Recent radiative hydrodynamic simulations suggest that their atmospheres may be the location of large-scale convective motions. Aims. As supergiant convection is expected to generate supersonic motions and shocks, we seek constraints on these atmospheric motions and their possible relation with mass-loss rate...

A two-fluid hydrodynamic model of a two-dimensional gas-solids fluidized bed is used to calculate the shape of an isolated bubble. The calculations are done by applying four different discretization schemes to the convection term. The bubble shape calculated by using the first order upwind scheme is unphysical and pointed, where as the bubble shape calculated by the second order schemes SMART, ...

The hydrodynamic characteristics of flow regime were studied employing different draft tubes during the spouted bed roasting of groundnuts and the dimensionless parameters were employed for predicting the flow regime. The estimated Reynolds's number (Re) under the turbulent convection regime was ≈ 8399. The size of the draft tubes employed ranged from 0.175 to 0.375 m length and 0.065 m diamete...

background and aims: adenovector gene transfer induces inflammatory response that finally leads to vector removal from delivered site. the effect of hydrodynamic pre-injection on adenovector mediated liver inflammation remained elusive. materials and methods: different mice groups were pre-treated by hydrodynamic saline, dexamethasone or nothing prior to adeno-luciferase administration. their s...

The effect of radiation on a steady two-dimension magneto-hydrodynamic mixed convection flow from a vertical plate embedded in a saturated porous media with melting is analyzed.The non-linear partial differential equations, governing the flow field under consideration, have been transformed by a similarity transformation into a system of non-linear ordinary differential equations and then solve...