Description of a flow of a gas-condensate mixture in an axisymmetric capillary tube by the density-functional method

An isothermal flow of a two-phase multicomponent mixture through a small-diameter capillary tube is examined by the density-functional method. For low ratios of the characteristic radius of the capillary to its length, a general form of the dominating term in the asymptotic solution is found. An improved version of the law of mixture transfer is obtained. The form of possible corrections to the Darcy law for the filtration rates of the phases is discussed.