On unstable perturbations in filtration theory
On unstable perturbations in filtration theory
(Russian, English abstract)
Abstract:
This review paper considers the types of loss of stability of filtration flows. Characteristic dispersion
curves are presented that correspond to transitions to instability within the Darcy theory at zero, finite and infinite values of the wave number, as well as at all wave numbers simultaneously. It is
shown that the use of the generalized Brinkman filtration equation suppresses short-wave instability corresponding to infinite values of the wave number. As calculations show, the obtained values of
characteristic sizes of the fastest growing disturbances are more than an order of magnitude smaller than a millimeter. This value is comparable to or smaller than the pore size of most natural porous
media, for which the study of the stability of filtration flow is relevant. Therefore, a conclusion is made about the inapplicability of filtration theory methods to a wide class of problems leading to
the formation of small-scale instability. It is assumed that such problems should be studied using micromechanics methods.
Keywords: Porous media, interface, instability