In this work, we augment our earlier finite element formulation to address temperature discontinuities at liquid-vapor phase interfaces. Using this methodology, we study the flow of Argon vapor in a planar heat pipe and explore the consequences of a finite interfacial temperature jump. Our results indicate that accounting for temperature discontinuities at phase-interfaces leads to only a slight improvement in the prediction of mass fluxes as compared
to the case when temperature continuity is assumed. This contrasts with
the large improvement in the prediction of temperature profiles.