Local thermal equilibrium and ideal gas Stephani universes

Symmetries of the Stephani Universes

Symmetries of the Stephani Universes and Related Solutions

Some years ago Stephani derived the general solution of Einstein's eld equations for a conformally at perfect uid. In these metrics the spacelike hypersurfaces orthogonal to the uid ow have constant curvature. The metrics with non-zero expansion involve ve arbitrary functions a, b, c 1 , c 2 and c 3 of time t. It is shown that any Killing vectors must be tangent to the constant curvature hypers...

Modelling Bidispersive Local Thermal Non-Equilibrium Flow

In this work, we present a system of equations which describes non-isothermal flow in a bidispersive porous medium under conditions of local thermal non-equilibrium. The porous medium consists of macro pores, and in the solid skeleton are cracks or fissures which give rise to micro pores. The temperatures in the solid skeleton and in the fluids in the macro and micro pores are all allowed to be...

Slip flow in porous micro-tubes under local thermal non-equilibrium conditions

In the present work, forced convection heat transfer of slip flow in porous micro-tubes with local thermal non-equilibrium between the gas and the solid matrix is investigated numerically. For this purpose, the flow is considered hydrodynamically developed but thermally developing. The Darcy-Brinkman-Forchheimer model in conjunction with separate energy equations for the gas and the solid matri...

Analytical model for thermal boundary conductance and equilibrium thermal accommodation coefficient at solid/gas interfaces.

We develop an analytical model for the thermal boundary conductance between a solid and a gas. By considering the thermal fluxes in the solid and the gas, we describe the transmission of energy across the solid/gas interface with diffuse mismatch theory. From the predicted thermal boundary conductances across solid/gas interfaces, the equilibrium thermal accommodation coefficient is determined ...