Interfacial Waves in Accelerated Gas-Liquid Two-Phase Flows

通过空气-水系统实验，模拟了蒸发器管内气液两相加速流动。用电导法测量了水平矩形通道中界面波的特性。结合功率谱密度和液膜厚度变化的互相关函数，分析了扰动波的产生、生长和衰减机理。(1)在加速通道内通过目视观测构建流型图。当气体流速较低时，通道高度影响流型转变。与使用单位通道宽度的液体质量流量作为参数的结果相比，使用表面气液速度可以很好地预测流型转变。(2)明确了水平矩形通道中加速两相流的界面波特征。在加速度作用下，二维波发生变形，并出现扰动波。分析了这些波的振幅和频率之间的相互关系。(3)空气-水系统的模拟实验对研究蒸发器管内界面波特性是有效的。

An accelerated gas-liquid two-phase flow in an evaporator tube was simulated by an air-water system experiment. Characteristics of interfacial waves in a horizontal rectangular channel were measured by the electrical conductance method. Mechanisms of generation, growth and decay of the disturbance wave were analized considering the power spectrum density and the cross correlation function of variations of the liquid film thickness.(1) Flow pattern maps were constructed from the visual observation in the accelerated channels. At lower gas flow rate, the channel height affected the flow pattern transition. Flow pattern transitions were predicted fairly well by using the superficial gas and liquid velocities, compared to the results using liquid mass flow rate per unit channel width as a parameter.(2) Characteristics of interfacial waves of accelerated two-phase flow in a horizontal rectangular channel were clarified. Under acceleration two-dimensional waves were deformed and the disturbance waves appeared. Mutual relationships between amplitudes and frequenices of those waves were analized.(3) The simulation experiment by an air-water system was considered to be valid for the examination of interfacial wave characteristics in the evaporator tube.