Dynamic adsorption in a radial flow of a solution around a spherical cavity

The paper studies the local variation of the concentration of a neutral dilute solution during its radial flow around a spherical cavity in the approximations of an adsorption layer and the Langmuir adsorption kinetics. The authors used the boundary-layer method and the method of asymptotic series expansion of the solution in a small parameter, which is the ratio of the time of establishing an adsorption equilibrium to the time of establishing a steady diffusion layer around the cavity. The equations obtained for a zeroth approximation were studied analytically and numerically. In the case of high-frequency oscillations of the cavity in the solution, a solution of the problem was found that corresponds to the process of “straightened” adsorption or “pumping” an admixture into the adsorption layer.