SOLUTE TRANSPORT IN NONSTATIONARY VELOCITY-FIELDS

The paper addresses the problem of transport of inert solutes in rando m nonstationary velocity fields. General equations for the first two m oments of the particle trajectory are derived. It is shown that they c an be solved analytically in quadratures for the case of quasi-unidire ctional mean flows. The solution generalizes the previous results obta ined for transport in velocity fields which are uniform in the average . The theory is applied to the case of transport in media displaying a linear trend in the mean logconductivity. The dynamics of particle di splacements is discussed for the case of two-dimensional media with is otropic fluctuations of the logconductivity.