Abstract:

The microbubble behavior on platinum microheaters immersed in parallel microchannels during flow boiling was experimentally investigated, with the heater driven by pulse-heating.With increasing heat flux of rear face heater, three representative types of microbubbles, corresponding to three instable tendencies were identified.The relations between boiling instability and bubbles behavior were analyzed.The conclusions indicated that transitions among these bubbles and various departure modes strongly depended on the instability of flow boiling in microchannels.Meanwhile, heating power of the rear face heater was also one of the main factors that affected bubbles incipience and diameters.The results of present study can provide powerful basis for the future design of new micro-fluid functional devices.

Key words:

微汽泡, 铂膜微加热器, 脉冲加热, 流动沸腾不稳定性

摘要： 在流动沸腾的微通道内，以脉冲加热驱动微铂膜产生的汽泡为研究对象，通过实验的方法对处于流动沸腾微通道内的铂膜表面上的汽泡行为进行了研究。发现了三种代表性汽泡形态：类球形汽泡，锥形汽泡，液膜汽泡；分析了微通道内不同加热功率下流动沸腾的不稳定性与这些汽泡的形态和相互转化的关系。结果表明，微通道内不稳定性流动沸腾的振动流态，是铂膜上形成各种泡并以不同方式脱离铂膜的原因；背面加热膜的功率大小也是影响铂膜长泡以及汽泡大小的主要因素之一。研究结果为进一步开发设计新型的微流体功能器件提供了基础和依据。

关键词:

微汽泡, 铂膜微加热器, 脉冲加热, 流动沸腾不稳定性