Instability in thin layer of liquid confined between rigid walls at different temperatures

Abstract

Combined thermocapillary and buoyancy convection in a thin layer of liquid, confined in a rectangular cavity, is investigated numerically. The fluid is heated from one side. Although the aspect ratio is very large, the existence of a thermal boundary layer near the rigid walls gives different results compared with convection in an infinite liquid layer. The temperature drops near the walls are rapidly increasing with the growth of the imposed temperature difference. As a result, in the core of the cavity the horizontal temperature gradient is up to 3 times smaller than the imposed Δ T/ L just before the onset of oscillatory instability. Further study is focused on the return-flow basic state, its transition to a steady multicellular state and the onset of time-dependent flow from the steady multicellular cell.