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

在本研究中，分别开发并验证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头方法。对小通道（即窄矩形通道）内的两相流动进行了局部测量，得到了空隙率、界面面积浓度（IAC）和气泡直径等局部流动参数。在此基础上，对已有的两相摩擦乘法器相关性、已有的漂移通量分布参数和漂移速度相关性以及已有的IAC相关性进行了验证或修正。考虑破碎气泡的特性，推导了窄矩形通道的界面面积输运方程。分别模拟了气泡间的随机碰撞和湍流涡流与气泡的碰撞。用现有数据库对包含汇项和源项的新IATE进行了可靠性评价。

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.