| Vapour transport in a gas saturated porous medium with surface convection occurs in many applications. For the Phoenix Mars mission, local convection over the regolith is studied to obtain a better insight into water vapour transport in the vicinity of the Lander. A 3-D, transient, transport model, extended to admit a layer of porous material is used to model two different local atmospheric flows: an early phase of the near surface natural convection and horizontal winds. Variable parameters are regolith thickness, domain pressure and temperature, imposed wind velocity (inflow) and surface temperature. The results of the numerical simulations are summarized by means of a special Sherwood number to quantify these complex effects. Theoretical and experimental data were used to partially validate the numerical simulations. Lastly, experiments were performed to investigate the effects of surface natural convection on vapour transport in a porous medium to partially validate the numerical model. |
