搅拌流内大振幅界面波特性研究

针对竖直管内不同工况下气液两相搅拌流内的大振幅界面波特征参数(波形、波幅、波长和频率等)及运动特性进行了实验研究,系统分析了流动参数对大振幅界面波特征参数及运动特性的影响规律。结果表明:由于重力和气流剪切力在大振幅界面波不同运动阶段的影响程度不同,大振幅界面波在运动过程中存在与气流先逆向后同向的运动特点,证明了液泛现象普遍存在于搅拌流内,揭示了造成搅拌流液膜振荡剧烈的原因;搅拌流内,大振幅界面波波形符合正态分布函数特征,且波幅较环状流内扰动波波幅大,但是波幅和波长变化趋势与环状流内扰动波变化趋势相似,即波幅和波长随着气速的增大而减小,随液量的增大而增大,且当气速较小时,临界波幅随着液量的增加逐渐趋于定值;而大振幅界面波平均产生频率随气速和液速的增大而增大。

Study on properties of huge waves in churn flow

The present paper focused on huge wave's feature parameters (e. g. wave shape,wave ampli-tude,wave length,wave frequency,etc. )and kinetic properties in gas-liquid two-phase churn flow in vertical pipe under different working conditions and conducted experimental study. The effects of flow parameters on feature parameters and kinetic properties of huge wave were investigated. The results indicate that the competi-tion between gravity and shear force under different flow conditions affects the wave behavior significantly. The huge wave firstly moves downward due to the gravity till it reaches a critical amplitude for the flow reversal, which demonstrates that the flooding of the film is a characteristic of the churn flow throughout the regime and the reason makes churn flow highly disturbed. The shape of huge wave can be described by a normal-distribu-tion function,and the wave amplitude of huge wave is larger than disturbance wave in annular flow. The am-plitude and wavelength of huge wave decrease with the increase in gas flow rate but increase with the increas-ing liquid mass flow rate,which is similar to annular flow. At lower gas superficial velocities,the critical amplitude asymptotically approaches a constant value at greater liquid mass flow rates. The wave frequency is found to be proportional to the gas and liquid velocity.