Physics

Critical heat flux

Nucleate boiling

Heat transfer

Mechanics

Boiling

Heat flux

Metallurgy

Materials science

Flow boiling

Flow (mathematics)

Flux (metallurgy)

Thermodynamics

Heat Transfer-Asian Research

Microchannel two‐phase flow is an effective cooling method used in microelectronics, in which the heat flux density is unevenly distributed usually. The paper is focused on numerical study the effect of aspect ratio on the flow boiling of microchannels with nonuniform heat flux. The heat source is a three‐dimensional (3D) integrated circuit. 3D microchannel model and volume of fluid method are coupled in numerical simulation. The results show that the aspect ratio has no relationship with the two‐phase pressure drop of the microchannel. It has a certain influence on the distribution of bubble shape. In terms of the heat transfer coefficient, the aspect ratio has a certain influence on a section of the inlet. Due to the nucleate boiling, the convective heat transfer in the remaining areas is the dominant factor and the average heat transfer coefficient is mainly determined by the heat flux at the bottom of the channel.

Effect of aspect ratio on saturated boiling flow in microchannels with nonuniform heat flux