Two-Phase Flow in Microchannel Heat Sink with Nearly Uniform Heat Flux Boundary Condition

A thermal microsystem, integrated with pressure and temperature microsensors, is fabricated to study convective boiling under nearly uniform heat flux boundary condition. The temperature and pressure distribution along the microchannel is measured correspondingly. The pressure increases with input power when two phase flow develops. A pressure peak appears at the location of liquid-vapor interface region. The transient temperature and pressure fluctuation is also measured. The dominant frequencies of the temperature and pressure fluctuation are the same values at the liquid-vapor interface region and this dominant frequencies increase with input power. Simultaneously, the qualitative visualizations of the evolving flow patterns have been correlated with the quantitative temperature and pressure measurements.