For developing falling film evaporation device that is suitable for organic fluid cogeneration, the gas-liquid two-phase countercurrent R113 falling film was simulated by using the RNG k-ε model in the vertical tube.The flow pattern and velocity characteristics of liquid film are analyzed.The results indicate that along the longitudinal direction, the velocity increases and the tendency tends to gently.The film thickness changes from uniform to uneven.Three kinds of flow patterns are founded, which are the steady flow, the wave flow and the shock flow.In the flow process, the liquid has a shock wave but no fracture.Compared with the theoretical value, the simulation results are reliable.%为研发有机工质余热发电降膜蒸发装置,采用RNG k-ε模型对氟利昂(R113)竖直管内气液两相逆流降膜进行数值模拟.对液膜的流动形态和速度特性进行详细的分析研究.研究发现在沿管长方向的流动过程中,流速呈现出逐渐增大的趋势,但随着流动的发展,这种增势变缓.膜厚由均匀变至厚薄交替并呈现出平稳段、波动段和震荡段三种不同的流动形态,虽然出现震荡波动但无断裂,与理论值对比模拟结果较可靠.
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