CONVECTIVE INSTABILITY OF MOIST GAS IN A POROUS-MEDIUM

Flow and heat transfer in a porous medium filled with an ideal gas of 100% humidity are strongly coupled. The transitions between the conduc tive and convective regimes can be found by stability analysis of the governing equations. A dimensionless Rayleigh number controls the heat and flow regime. Stability conditions obtained by perturbation analys is show that the critical Rayleigh number depends heavily on the vapor pressure. The moist gas studied here is much less stable than a dry i deal gas, because the latent heat carried by a warm moist gas is much greater than the sensible heat.