Convection flows driven by laser heating of a liquid layer: experimental and numerical investigation

When a fluid is heated by the absorption of a continuous laser wave, the fluid density decreases in the heated area. This induces a pressure gradient which generates internal motion of the fluid. Due to masse conservation, convection eddies emerge in the sample. Despite several studies on laser heating in fluids, the key link between the induced temperature gradient and the resulting convective flows as a function of the laser parameters is still poorly understood. To investigate these laser-driven bulk flows at the microscopic scale, we combine an experimental investigation of the temperature field and the velocity in the sample with a numerical approach. This allows a quantitative description of the convection flows induced by the absorption of light in a thin liquid layer.