Physics of microstructures enhancement of thin film evaporation heat transfer in microchannels flow boiling

Physics of microstructures enhancement of thin film evaporation heat transfer in microchannels flow boiling

Performance enhancement of the two-phase flow boiling heat transfer process in microchannels through implementation of surface micro- and nanostructures has gained substantial interest in recent years. However, the reported results range widely from a decline to improvements in performance depending on the test conditions and fluid properties, without a consensus on the physical mechanisms resp...

Flow Boiling Heat Transfer in Microchannels

Pool Boiling Heat Transfer Enhancement Through Nanostructures on Silicon Microchannels

Uniform silicon nanowires (SiNW) were successfully fabricated on the top, bottom, and sidewall surfaces of silicon microchannels by using a two-step electroless etching process. Different microchannel patterns with the channel width from 100 to 300 lm were first fabricated in a 10 mm 10 mm silicon chip and then covered by SiNW with an average height of 10–20 lm. The effects of the microchannel ...

Heat Transfer Mechanisms During Flow Boiling in Microchannels

The forces due to surface tension and momentum change during evaporation, in conjunction with the forces due to viscous shear and inertia, govern the two-phase flow patterns and the heat transfer characteristics during flow boiling in microchannels. These forces are analyzed in this paper, and two new nondimensional groups, K1 and K2 , relevant to flow boiling phenomenon are derived. These grou...

Ultrahigh Flux Thin Film Boiling Heat Transfer Through Nanoporous Membranes.

Phase change heat transfer is fundamentally important for thermal energy conversion and management, such as in electronics with power density over 1 kW/cm^2. The critical heat flux (CHF) of phase change heat transfer, either evaporation or boiling, is limited by vapor flux from the liquid-vapor interface, known as the upper limit of heat flux. This limit could in theory be greater than 1 kW/cm2...