Surface Structure Enhanced Microchannel Flow Boiling

Prediction of the onset of nucleate boiling in microchannel flow

The onset of nucleate boiling in the flow of water through a microchannel heat sink was investigated. The microchannels considered were 275 lm wide by 636 lm deep. Onset of nucleate boiling was identified with a high-speed imaging system and the heat flux at incipience was measured under various flow conditions. An analytical model was developed to predict the incipient heat flux as well as the...

Flow Boiling in an Asymmetrically Heated Single Rectangular Microchannel

Surface Acoustic Wave Driven Microchannel Flow

We demonstrate that the propagation of surface acoustic waves, arising from the excitation of the acoustic field on a piezoelectric crystal (lithium niobate) substrate, along the sidewalls of microchannels (50 μm or 280 μm wide and 200 μm deep) fabricated in the substrate, can give rise to throughflow with velocities of the order 10 mm/s. This streaming flow in the direction along which the sur...

Subcooled two-phase flow boiling in a microchannel heat sink: comparison of conventional numerical models

Subcooled flow boiling in multi-microchannels can be used as an efficient thermal management approach in compact electrical devices. Highly subcooled flow boiling of HFE 7100 is studied in two microchannel heat sinks to choose a proper numerical model for simulating boiling flows in microchannels. Results of five different numerical models, including Volume of Fluid (VOF), Eulerian boiling, Eul...

A comprehensive flow regime map for microchannel flow boiling with quantitative transition criteria

Due to the critical role of vapor confinement in establishing distinct flow and heat transfer characteristics in microchannels (as distinct from those in larger channels), the conditions under which such confinement occurs in microchannels are of great interest. It is shown in the present work that channel dimensions and flow properties alone, as proposed in past studies, are insufficient for d...