# The effect of phase change on stability of convective flow in a layer of volatile liquid driven by a horizontal temperature gradient

## TL;DR

This paper investigates how phase change influences the stability of buoyancy-thermocapillary convection in a volatile liquid layer under a horizontal temperature gradient, highlighting the role of gas phase composition and heat transport.

## Contribution

It provides a linear stability analysis showing the impact of gas phase transport and phase change on convection onset, extending understanding at atmospheric conditions.

## Key findings

- Gas phase transport significantly affects convection thresholds.
- Decreasing air concentration raises the instability threshold.
- Phase change effects are notable even at atmospheric conditions.

## Abstract

Buoyancy-thermocapillary convection in a layer of volatile liquid driven by a horizontal temperature gradient arises in a variety of situations. Recent studies have shown that the composition of the gas phase, which is typically a mixture of vapour and air, has a noticeable effect on the critical Marangoni number describing the onset of convection as well as on the observed convection pattern. Specifically, as the total pressure or, equivalently, the average concentration of air is decreased, the threshold of the instability leading to the emergence of convective rolls is found to increase rather significantly. We present a linear stability analysis of the problem which shows that this trend can be readily understood by considering the transport of heat and vapour through the gas phase. In particular, we show that transport in the gas phase has a noticeable effect even at atmospheric conditions, when phase change is greatly suppressed.