管流式冲蚀装置异径管固液两相流场数值分析

Erosion-Corrosion of Solid-Liquid Phase Flow-Field in Heterodiamter Pipeline:A Simulation and Experimental Study

为深入研究管流式冲蚀装置异径管内固液两相流场对管壁面的影响,以砂粒为工质,采用Standard k-ε湍流模型、空化模型和冲蚀模型对DN100-DN50异径管进行数值模拟,在流速2、3、4、5 m/s时和温度300、310、320、330 K时,分别获得测试管壁面冲蚀和空化的分布规律。结果表明:测试管的冲蚀速率随着流速的增大而逐渐增大,随温度的升高而轻微变化;在流速为2、3和4 m/s时,测试管的空气体积分数较小近似为零,在流速为5 m/s时,测试管入口处出现空泡现象,其他区域空气体积分数近似为零。测试管的空气体积分数随温度的升高而无明显变化。在不同流速下冲蚀非稳定长度仿真结果与试验结果分别相差1.74%,1.67%,1.48%,1.39%。因此,管流式冲蚀装置的异径管连接方式设计合理,可以忽略空化对测试管的破坏作用,能够确定冲蚀非稳定长度,为后续研究管道冲刷腐蚀行为以及分析测试管腐蚀位置提供理论依据。

The solid-liquid phases(sand and water)flow field,inside a hetero-diameter pipeline,was empirically approximated,mathematically formulated by Standard k-εTurbulence/Cavitation/Erosion models,theoretically analyzed,numerically simulated with Fluent and experimentally evaluated with the lab-built test platform.The influence of the temperature and intake flow velocity on the distributions of erosion/cavitation on pipeline walls was investigated.The simulated results show that the flow velocity has a major and temperature has a minor impact.To be specific,as the flow velocity increases from 2 to 5 m/s,the erosion rate increases,accompanied by weak temperature dependence,and the cavitation starts appearing at 5 m/s only at the input.When it comes to the simulated and measured'unstable erosion lengths',the discrepancy was below 2%.We suggest that the simulated results be of some technological interest in industrial design and applications of solid-liquid slurry flow pipelines.