双流体雾化喷嘴的液膜模型
Liquid film model for the flow in a twin-fluid atomization nozzle

双流体雾化喷嘴出口的气液流动可认为是非充分发展的环状流动，借助已有的气液两相流模型无法准确描述其液膜形成过程。为此，该文基于环状流假设，分析比较了3种不同的滑移比模型对液膜厚度和液体质量流率的预测特性，并与实验数据进行比较。结果表明：无滑移模型对液膜厚度的预测值偏低；而基于充分发展环状流假定的Ishii经验关联式模型对液膜厚度的预测值偏高；根据实验数据提出的滑移比模型，考虑了环状流不充分发展的特征、气液质量比（gas to liquid mass ratio，GLR）和入口压力的影响，能够准确预测喷嘴的流量特性及液膜厚度。
Abstract：The flow of gas-liquid mixtures in atomization nozzles is generally believed to not be fully developed annular flow but liquid film formation cannot be described accurately by traditional gas-liquid two phase flow models. This paper compares three slip ratio models for annular flow and their predictions of the liquid film thickness and the liquid mass flow rate with experimental data. The non-slip model under predicts the film thickness while the Ishii empirical correlation based on the hypothesis of fully developed annular flow over predicts the film thickness. A slip model was then developed from experimental data based on a non-fully developed annular flow model, the gas-liquid mass flow ratio and the inlet pressure. This model more accurately predicts the flow characteristics and the liquid film thickness in the nozzle than the other models.