The conduction-diffusion regime has been defined as a stationary state of the system for which the profiles of velocity, temperature, mass fraction and pressure gradient are one-dimensional over some section of the height. The existence of the regime in a two-dimensional cavity has been demonstrated, simultaneously validating the numerical and analytic solutions.
In the regime, the size of
the end-zone relative to the cavity width
appears to be independent of the aspect ratio, suggesting a
simplification of the functional form of the overall heat and mass
transfer rates. If the combined
Grashof number is sufficiently large (the required value increasing with
vertical aspect ratio) the regime is destroyed by penetration of convective
effects from the end-zones into the core.