Numerical simulation of growth of a vapor bubble during flow boiling of water in a microchannel
Numerical simulation of growth of a vapor bubble during flow boiling of water in a microchannel
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DOI：
10.1007/s10404-004-0021-8
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发表时间：
2005-05-01
影响因子：
2.8
通讯作者：
Kandlikar, SG
中科院分区：
文献类型：
--
作者：
Mukherjee, A;Kandlikar, SG
本研究是进行数值分析的水通过微通道流动过程中的汽泡的生长。完整的Navier-Stokes方程，沿着与连续性和能量方程，使用SIMPLER（半隐式方法的压力链接方程修订）方法求解。使用水平集技术捕获液体-蒸气界面。微通道截面为200 μ m见方，气泡位于通道中央，周围有过热液体围绕，气泡在通道中初始生长稳定，充满通道后迅速轴向膨胀。当气泡伸长时，在气泡和通道之间观察到捕获的液体层。气泡生长速率随来流液体流速的增加而增大，随雷诺数的增加而减小。蒸汽补丁在墙壁上的形成被发现是依赖于时间的气泡需要填补了通道。发现气泡的上游界面在气泡生长过程中表现出正向和反向运动。结果表明，在特定条件下，重力对气泡生长速率的影响很小。从数值计算结果中得到的气泡生长特征被发现是定性相似的实验观察。
The present study is performed to numerically analyze the growth of a vapor bubble during flow of water through a microchannel. The complete Navier-Stokes equations, along with continuity and energy equations, are solved using the SIMPLER (semi-implicit method for pressure-linked equations revised) method. The liquid-vapor interface is captured using the level set technique. The microchannel is 200-mu m square in cross-section and the bubble is placed at the center of the channel with superheated liquid around it. The results show steady initial bubble growth followed by a rapid axial expansion after the bubble fills the channel cross-section. A trapped liquid layer is observed between the bubble and the channel as it elongates. The bubble growth rate increased with the incoming liquid superheat, but decreased with Reynolds number. The formation of a vapor patch at the walls is found to be dependent on the time the bubble takes to fill up the channel. The upstream interface of the bubble is found to exhibit both forward and reverse movement during bubble growth. The results show little effect of gravity on the bubble growth rate under the specified conditions. The bubble growth features obtained from the numerical results are found to be qualitatively similar to experimental observations.