Modeling of transport processes in the presence of substance-locking effects

Mass-transport processes under the action of an external field in a medium with piecewise-constant properties and special equations of state are inves tigated both analytically and numerically. An analytical solution of hyperb olic conservation law on which some algebraic restrictions are imposed is p resented. Special emphasis is given to the construction of a correct mathem atical model for transport processes. The technique of solving the generali zed Riemann problem with two initial discontinuities is developed and rigor ously revised. The influence of diffusion effects on the solution profile, especially in the vicinity of a stationary contact discontinuity, is studie d by numerical methods. An example of a real mass-transport process under t he impact of an external force in which a part of the substance is entrappe d between stationary discontinuities is presented. This physical effect was observed experimentally for the first time by the authors in electrophores is-a separation method for chemically reactive multicomponent mixtures by m eans of an applied electric field.