Microbubble emission boiling in microchannel and dynamical behaviors of vapor bubbles
Details
This paper reports an experimental investigation of "Microbubble Emission Boiling (MEB)" in a microchannel. The microchannel is 50 mm in length including heated length 20 mm, 1 mm in width and, 200 μm and 1000 μm in height. MEB in microchannel realized high heat flux over 4.5 MW/m^2 with low flow rate of 20 cc/min and low pressure drop nearly equal to that of single phase condition. Under conditions of higher heat flux more than certain value, however, saturate boiling at downstream took place and fluctuated annular flow was observed. High speed video camera captured how vapor bubbles emit microbubbles in pool boiling system. An interface of a primary vapor bubble on the heated surface undulated and several microbubble were produced from the ripples without departure of the primary bubble.
