Convection in a thin liquid layer with local heating in the absence of marangoni effect

Abstract

In this study, we investigated convection dynamics in a thin liquid layer subjected to local laser heating in the absence of the Marangoni effect. Using a 1 mm water layer with a glass substrate in contact with the water surface to suppress surface tension-driven flows, we examined pure buoyancy-driven convection mechanisms. Particle Image Velocimetry (PIV) and thermal imaging techniques were employed to visualize flow patterns and temperature distributions. Our results revealed characteristic thermal equilibrium after 80-100 seconds of heating and the formation of a hexagonal convection pattern with six distinct divergence points