管道冲刷腐蚀缺陷对超声测量流体速度的影响

针对管道内流体冲刷腐蚀管壁变薄最终导致管内流体泄漏的问题,采用超声多普勒检测法测量管道内流体速度分布以判断管壁的损伤程度。建立带有缺陷的管道内流体模型,通过CFD数值模拟分析了不同雷诺数以及不同缺陷下管道内流体状态。利用含有不同预制缺陷管壁厚度的有机玻璃作为实验测量对象,超声多普勒检测法测量参量分别为入射频率8MHz,入射角10°。CFD数值模拟以及UVP实验结果均表明,在缺陷不同位置处的流体速度分布具有较大区别,具体表现为在缺陷位置处缺陷越大流体速度分布越平缓;在缺陷临界点位置处产生了涡流现象,随着缺陷的增大和流量的增大,涡流现象将更加明显;在远离缺陷位置后的流体速度分布与缺陷位置前的区别并不明显。

Erosion and Corrosion Defect Influence on Flow Velocity in Pipeline Using Ultrasonic Measurement

Considering the problem that the erosion and corrosion from the pipe wall will lead to the leakage of the fluid,the ultrasonic Doppler velocity profiler (UVP) is used to measure the fluid velocity distribution in the pipeline to determine damage degree of the pipe wall.Numerical simulations are carried out to analyze the fluid state under different reynolds numbers and different defects by establishing a fluid model in the pipeline with defects.Using the plexiglass with different prefabricated defects wall thickness as an experimental object.The parameters of UVP include the ultrasonic basic frequency is 8MHz and the incident angle is 10 degree,respectively.Both the CFD numerical simulation and the UVP experimental results show the fluid velocity distribution has a great difference at different locations from the defect,which is manifested by the fact that the defect is larger at the defect location to cause the fluid velocity distribution gentler.Vortex phenomenon occurs at the defect critical location, which increases distinctly with the increasing of the defect and flow rate.There is no obvious difference between the fluid velocity distribution after and before the location of the defect.