多孔介质流动沸腾微观模型实验研究

多孔通道内流动沸腾广泛应用于热管、高效换热器、航天热防护等领域,认识孔隙尺度相变典型行为及特点有助于理解多孔介质内沸腾传热机理,进而改进多孔介质内部流体相变模型。基于此,本文搭建了二维多孔介质内流动沸腾实验台,对微米级多孔通道内部流动沸腾现象及气泡行为进行研究。实验发现在毛细力、黏性力和惯性力的共同作用下,多孔介质内的流动沸腾形态显著区别于直通道内的沸腾,存在局部气泡堵塞、合并和液膜蒸干、再润湿等行为。该研究有助于增强对相变过程的理解,并为多孔结构优化设计提供指导。

Experimental Investigation of Flow Boiling in Porous Media With Micromodels

Flow boiling inside porous media is widely used in many applications,such as heat pipes,high-efficiency heat exchangers,and aerospace thermal protections.To understand the mechanism of boiling heat transfer in porous media.and modify the two-phase model,it’s necessary to take deep insight into phase change behavior and characteristic at pore-scale.Based on this consideration,an experimental investigation with two-dimensional micromodels is carried out to study the flow boiling phenomenon and bubble behavior in a micron-sized chip with porous structures.The results show that,due to the effect of capillary pressure,viscous force and inertial force,flow boiling in porous media is different from that in microchannels.and there are unique phenomenon of local bubble trap and coalescence,and liquid film dry out and re-wetting.This research helps to understand the phase change process,and to guide the design of cooling systems.