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蒸发薄液层的热毛细对流实验
Alternative TitleThermocapillary Convection Experiment of the Thin Evaporating Liquid Layer
乔莉莉
Thesis Advisor刘秋生
2019-05-30
Degree Grantor中国科学院大学
Place of Conferral北京
Subtype硕士
Degree Discipline流体力学
Keyword热毛细对流,蒸发速率,热流体波,温度分布,纳米流体
Abstract

电子元器件的集成化和小型化,使其有效散热面积日趋减小,局部产热增
加,严重影响了其性能和使用寿命。蒸发冷却良好的冷却效果,使其成为有望解
决高散热难题的先进技术之一。在热管、毛细泵环等众多蒸发冷却设备中,都存
在由强表面温度梯度引发的热毛细对流,是影响微型换热设备换热效果的重要
因素。蒸发是一个非平衡过程,气液界面处,化学势不连续,传统的热力学平衡
不再成立,这使得带有蒸发界面的热毛细对流问题更为复杂。本文以蒸发液层为
研究对象,结合国内外学科发展前沿,开展了系统的实验研究,探索热毛细对流
与蒸发过程的耦合机理。
采用挥发性流体工质作为实验液体,观测了水平温度梯度作用下,矩形液层
的热毛细对流。采用红外热成像技术测量了蒸发界面的温度分布,同时采用共聚
焦位移计观测界面位置变化。实验研究了不同温差下瞬时蒸发速率与所加温差
的关系,观测到三种流型:混沌态,镜像对称的热液波及基态流,最后得到了不
同流型对应的界面温度分布和温度演化。
纳米流体是一种新型的换热流体,是指将纳米颗粒均匀分散在水、油、醇等
基液得到的稳定的悬浮液。与纯工质实验对比,研究纳米颗粒的添加对液层界面
温度分布、瞬态蒸发速率的影响。

Other Abstract

With the integration and miniaturization of electronic components, the effective
heat-dissipation area decreases gradually, while the local heat flux is increasing,
which has an adverse effect on their performance and service life. Evaporative
cooling has excellent cooling effect, making it one of the promising technology to
enhance heat dissipation of next generation electronic components. Thermocapillary
convection induced by temperature gradient exist in many evaporative cooling
devices, such as heat pipes, capillary pumped loop, and it is an important factor
affecting the performance of all the micro heat exchange equipment. Evaporation
In this paper, evaporative liquid layers are chosen to be the research object of our
experiments to explore the coupling mechanism of evaporation and thermocapillary
convection.
Volatile working fluid is chosen to observe the thermocapillary convection in
a rectangle liquid layer subjected to a horizontal temperature gradient. The technique
we used are infrared imaging system and laser co-focal displacement meter.
Infrared imaging system are used to measure the temperature distribution of the
evaporation interface. And Laser co-focal displacement meter are used to observe
the interface position. Finally, we give the relationship of the average evaporation
rate and the imposed temperature gradient. Also, we give the interfacial
temperature distribution and flow field evolvement during different flow patterns.
As a new generation of heat transfer fluid, nanofluids are liquids(water, oils,
alcohol etc.) with stable suspensions of nanometer sized nanoparticles. Compared
with pure working liquids, the effect of nanoparticles on the transient evaporation
rate and interfacial temperature distribution are explored.

Language中文
Document Type学位论文
Identifierhttp://dspace.imech.ac.cn/handle/311007/79225
Collection国家微重力实验室
Recommended Citation
GB/T 7714
乔莉莉. 蒸发薄液层的热毛细对流实验[D]. 北京. 中国科学院大学,2019.
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