Natural convection flow of a radiating rarefied gas between concentric rotating spheres

The gasdynamics of a rarefied gas between two concentric rotating spheres is studied when the temperatures of the spheres are large enough for radiative heat transfer to be significant. Assuming the gas is slightly rarefied, the problem is modelled by the differential Navier Stokes equations and slip boundary conditions. When the buoyancy parameter is small, asymptotic approximation is adopted for the solution. On the assumption that the gas is optically thick and invoking the Rosseland differential approximation for radiation, the basic nonlinear approximation is integrated in a close form. The higher approximations which are linear are tackled by finite difference scheme. Quantitative discussions of the results are presented. The problem is important in vacuum technology, astrophysics and new aircraft and rocket technology. (author). 2 refs, 2 figs