Abstract: In this paper,the prediction of void fraction and pressure drop for upward gas-liquid annular flow in a vertical annulus is studied.According to the idea of Kelessidis(1989)for the flow pattern transition from churn to annular flow and the integral analysis method of Wallis(1969)for the velocity profile of single-phase flow in an annulus,a new model for prediction of void fraction and pressure drop is proposed based on considering the structural feature of the concentric annulus and the flow pattern characteristics.The present model is compared with existing models and the experimental data from this paper and the literature.It is in better agreement with experimental data than existing models.

Key words:

垂直同心环形管, 气液流动, 含气率, 压降, 环状流

摘要： 对垂直同心环形管内上升气液环状流的截面含气率及压降预测进行了研究.根据Kelessidis有关团状流向环状流转换的思路以及Wallis有关圆管内环状流积分分析的方法，考虑环形管的结构特征及环状流的流型特征，通过两相动力学理论建立了新的预测截面含气率及总压降的模型.将新模型及现有模型与实验数据的分析比较表明新模型对于总压降的预测效果较好.

关键词:

垂直同心环形管, 气液流动, 含气率, 压降, 环状流