Diffusion of water into purged volumes

In this paper, we report on an experimental and numerical effort to characterize removal and infiltration of atmospheric water vapor into a cavity purged with dry GN2. Multiple miniature sensors were used to track humidity and pressure inside a cylindrical enclosure with internal obstruction and a secondary volume. These measurements were compared against the well-known model of Scialdone. Although our data indicate a similar exponential-like decay, the t parameters differed from the predicted values. In addition, a numerical model was developed to study the purge and infiltration problem in more detail. The model utilizes an Advection-Diffusion solver for the contaminant species, and an incompressible Navier-Stokes solver for the flow velocity. Comparison of preliminary numerical results with the experimental data is presented.