Breakdown of a Locally Heated Liquid Film Shear-Driven in a Minichannel

The paper focuses upon shear-driven liquid film evaporative cooling of high-speed computer chips. Thin liquid films may provide very high heat transfer rates, however development of cooling system based on thin film technology requires significant advances in fundamental research. The paper presents new experimental data on flow and breakdown of a liquid film driven by the action of a forced gas flow in a horizontal minichannel (2 mm high), heated from a 22×6.55 mm heater. A map of isothermal flow regimes is plotted and the lengths of smooth region and region of 2D/3D wave occurrence are measured. The scenario of liquid film breakdown under heating is found to differ widely for different flow regimes. It is revealed that the critical heat flux at which film breakdown occurs for a shear-driven liquid film can be several times higher than that for a gravitationally-driven liquid film. This fact makes shear-driven liquid films very promising in high heat flux cooling applications.