A study on interfacial area transport in gas-liquid two-phase flow in mini-channels

在这项研究中，发展了一种用于二维和三维两相流局部测量的成像处理技术和四传感器探针法，并对其进行了验证。对微小通道(即窄矩形通道)内的两相流动进行了局部测量，得到了局部流动参数，如含气率、界面浓度和气泡直径。在此基础上，对现有的两相摩擦系数关联式、漂移通量分布参数关联式和漂移速度关联式以及IAC关联式进行了验证或修正。在考虑破碎气泡特性的基础上，推导了矩形窄缝通道的界面输运方程。气泡间的随机碰撞和湍流涡与气泡的碰撞分别模拟了气泡的合并和破裂。利用本数据库对新近建立的汇源项进行了评估，结果表明该方法是可靠的。

In this study, an imaging processing technique and a four-sensor probe method for local measurements in 2- and 3-D two-phase flows respectively were developed and verified. Local measurements of two-phase flows in mini-channels (namely narrow rectangular channels) were performed and the local flow parameters such as void fraction, interfacial area concentration (IAC) and bubble diameter were obtained. Based on the database, existing two-phase frictional multiplier correlations, existing drift-flux distribution parameter and drift velocity correlations and existing IAC correlation were verified or modified. By considering the crushed bubble characteristics, an interfacial area transport equation (IATE) was derived for the narrow rectangular channels. Random collisions between bubbles and impacts of turbulent eddies with bubbles were modeled for bubble coalescence and breakup respectively. The new IATE with the sink and source terms was evaluated to be reliable by the present database.