Transition Pool Boiling Heat Transfer Mechanisms on a Strip Heater Using Microscale Heater Arrays

该奖项是实验研究在过渡沸腾过程中使用独立控制的加热器的局部传热系数。 大多数现有数据都是针对相对较大表面的平均系数。 这项工作将利用微尺度加热器的阵列，每个小于平均气泡尺寸，控制局部加热和测量局部系数。 通过精确定位在蒸汽离开循环中何时何地大量的热量从壁中被移除，并将该信息与在那些时间对流体状态的视觉观察相关联，将获得关于过渡沸腾期间的重要传热机制的信息。 这些信息也可以导致对临界热通量的更好理解。 将获得关于壁空隙率、液体接触持续时间和液体接触分布的额外数据。 该实验技术有望应用于喷雾冷却、冲击冷却和颗粒冲击传热。

This award is to study experimentally the local heat transfer coefficients during transitional boiling using independently controlled heaters. Most of the existing data are for average coefficients over relatively large surfaces. This work will utilize an array of microscale heaters, each smaller than the average bubble size, to control local heating and to measure local coefficients. By pinpointing when and where in the vapor departure cycle large amounts of heat are removed from the wall and correlating this information to visual observations of the state of the fluid at those times, information about the important heat transfer mechanisms during transitional boiling will be obtained. This information can also lead to an improved understanding of the critical heat flux. Additional data will be obtained regarding wall void fraction, liquid contact duration, and the distribution of liquid contact will be secured. The experimental technique is expected to be applicable to spray cooling, impingement cooling, and particle impingement heat transfer.