T型微小通道内两相流分流与分离调控研究进展

Research Progress on Splitting and Separation of Two-phase Flow in T-type Microchannels

T型通道内的两相流流动和传递过程广泛存在于石油化工、生物制药、电子冷却等领域,而伴随社会进一步微型化、精细化的需求,微小尺度下T型通道内的流动过程及界面受力分析研究的重要性逐渐凸显。尺度的减小使得流动过程中主导作用力由重力等体积力转变为毛细力等表面力,界面运动及相作用机理也随之发生变化;同时,在微尺度下,等径与非等径T型微通道使得两相流流动呈现相分流和相分离两种具有本质区别的流动规律。从小尺度、微尺度和跨尺度三个方面对T型微小通道内两相流分流与分离的研究进展进行整理和分析。目前,等径微通道中相分流的研究多以实验为主,探索各种因素对两相分流特性的影响,诸如入口流型、表观速度、表面张力等;而真正针对非等径微通道内实现相分离的研究较少,且仅限于关注实现两相完全分离的条件及分离性能。鉴于微尺度尤其是非等径跨尺度T型微通道内相分离界面运动复杂、界面受力难于测量等原因,直至如今,相分离过程中的界面受力分析、分离机理以及相分布的主动调控仍是阻挡多孔结构在多相工质中高效利用的关键科学问题;急需实验与数值相耦合的机理研究,最终实现简单多孔结构在实际多相流场合中的广泛应用。

T-type channels widely exist in petrochemical industry,bio-pharmaceuticals,electronic cooling and other fields.With the need of miniaturization and refinement of application,the importance of the study on the flow process and interface force analysis in T-type channel at a micro-scale has gradually become important.The reduction of the scale causes the dominant force of flowing changing from body forces to surface forces,and the interface movement and mechanisms of phase interaction also change.At the same time,based on size comparison of the branch and the main channels,micro-channel can be divided into equal-diameter(ED)and non-equal-diameter(NED)T-type micro-channel,which lead two kinds of flow modes with intrinsic difference,phase spitting and phase separation.The research progress of two-phase flow splitting and separation in T-type microchannels from small scale,micro-scale and cross-scale were analyzed.The researches on phase spitting in ED micro-channel mainly focus on the influence of various factors on the split performance of two phases,such as the inlet flow pattern,superficial velocities and the surface tension.Whereas,there are a little studies on the phase separation in NED micro-channel which just focus on the conditions and separation performance of two-phase complete separation.As the complexity of interface movement and difficulty of force measurement at interface,the interface stress analysis,separation mechanism and active control of phase separation in NED micro-channel are still the key issue to effectively application of porous materials until now.It is urgently need to further study the mechanism with a coupling using of experiment and simulation,and finally realize the widely using of simple porous structures in practical multiphase flow.