Classification of Drying Models for Porous Solids

Investigation of Multiscale and Multiphase Flow, Transport and Reaction in Heavy Oil Recovery Processes

“…Because it is small, a further rescaling of the nucleation fraction and the cluster size is necessary. After some analysis, it is not di cult to show that for the cavity n ucleation model, the following scaling is valid (for example, for the constant pressure decline rate), f q while for the constant liquid withdrawal rate, 3 The last two equations are also accompanied by equation (32). The gas saturation expression for either case becomes 1 or h 1 = h 1 4 3 ; 3 2 in the respective cases.…”

“…9 we used a Rayleigh size distribution, 2 and 3 were kept constant t o t h e v alues 6:84 10 5 and 1:5 10 ;2 , respectively, while 4 varied over several orders of magnitude (from 10 ;12 to 10 ;6 ). During the nucleation period, the pressure declines almost linearly with time, P Dl 1; t D 3 , following equation (32). This decrease slows down as nucleation sets in, and when the maximum supersaturation is approached, the pressure reaches a local minimum.…”

“…The front retardation is due to the requirement to heat the rock matrix from the initial (injection) to the front temperature. Because of the increasing separation between the two fronts, the relevant boundary condition for our problem of interest, which is the steady-state in a frame of reference moving with the combustion front, would be @ @x = 0 (32) This also implies that ! f asx !…”

“…The traditional description relies on phenomenological approaches, in which the porous medium is a continuum, the dependent variables, like moisture content, are volumeaveraged quantities and the relation of fluxes to gradients is through empirical coefficients [9,17,31,32,33]. Such approaches essentially ignore the effect of the pore microstructure which is of key importance for a quantitative understanding of the process.…”

Convective Drying of Gels: Comparison Between Simulated and Experimental Moisture Profiles Obtained by X-ray Microtomography

“…Comparison of actual and predicted moisture profiles which develop during drying is an elegant a way to validate simulation models [1]. However, the difficulty to obtain experimental measurements has limited the ability of such drying models validation.…”