环状流液膜界面扰动波湍流诱导形成机制研究

Formation Mechanism for Turbulence Induced Disturbance Wave on Liquid Film of Annular Flow

为探明环状流液膜界面扰动波形成机制,以准确预测液膜质量输运和干涸(Dryout)型临界热流密度特性,本研究通过将高速摄像与液膜厚度电导传感结合的方法,分别对液膜界面波的演化行为和液膜厚度进行定性可视化分析和定量测量实验。结果表明,高湍动的气芯与液膜的相互作用在液膜界面上形成毫秒级不规则演变的涟波,高频涟波先驱经过一系列秒级自卷积演化成随机分布的扰动波;扰动波形成机制的数学模型表明,液膜界面扰动波的形成时间间隔符合伽马分布,伽马分布阶数与气相速度正相关但独立于液相流速。

To explore the formation mechanism of the disturbance wave from the perspective of accurately predicting the properties of the liquid droplet/film mass transport and dryout scenario, the high-speed camera and conductivity-based techniques are employed to visualize and measure the evolution behaviors of the interfacial waves and the liquid film thickness respectively. The millisecond-scale ripple waves induced by turbulent gas as precursors experience a series of second-scale self-convolution and evolve the random distribution of disturbance waves, and the time interval between the disturbance waves can be predicted statistically by the gamma distribution with an order n which increases with the gas superficial velocities but appears to be independent of the liquid superficial velocity.