Skip to main content
U.S. flag

An official website of the United States government

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS
A lock ( ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.

Onset of Convection in Two Liquid Layers with Phase Change

Published

Author(s)

Geoffrey B. McFadden, Sam R. Coriell, Katharine F. Gurski, David Cotrell

Abstract

We perform linear stability calculations for horizontal fluid bilayers that can undergo a phase transformation, taking into account both buoyancy effects and thermocapillary effects. We compare the familiar case of the stability of two immiscible fluids in a bilayer geometry with the less-studied case that the two fluids represent different phases of a single-component material, e.g., the water-steam system. The two cases differ in their interfacial boundary conditions: the condition that the interface is a material surface is replaced by the continuity of mass flux across the interface, together with an assumption of thermodynamic equilibrium that in the linearized equations represents the Claussius-Clapeyron relation relating the interfacial temperature and pressures. For the two-phase case, we find that the entropy difference between the phases plays a crucial role in determining the stability of the system. For small values of the entropy difference between the phases, the two-phase system can be linearly unstable to either heating from above or below. For larger values of the entropy difference the two-phase system is unstable only for heating from below, and the the Marangoni effect is masked by effects of the entropy difference.
Citation
Physics of Fluids
Volume
19

Keywords

bilayer convection, linear stability, Marangoni effect, phase-change convection, Rayleigh-Benard convection

Citation

McFadden, G. , Coriell, S. , Gurski, K. and Cotrell, D. (2007), Onset of Convection in Two Liquid Layers with Phase Change, Physics of Fluids, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=50867 (Accessed May 28, 2024)

Issues

If you have any questions about this publication or are having problems accessing it, please contact reflib@nist.gov.

Created December 31, 2006, Updated October 12, 2021