Gravity effects on the vapor-liquid interface very close to the critical temperature

Abstract

In a previous paper we have investigated the nature of the density gradients induced by gravity in gases close to the critical point. In the present paper the analysis is extended to include the effects of gravity on the vapor-liquid interface near the critical temperature. A smooth transition is found between the gravitationally induced density profiles in the one-phase region and the interfacial density profiles in the two-phase region. The thickness of the interface in the presence of gravity does not diverge at the critical temperature, but goes through a finite maximum at a temperature slightly below the critical temperature. When the critical temperature is approached from below, the surface tension crosses over from a power-law behavior with exponent 2ν to an asymptotic power law with exponent β − ην.