Solid particles entrained in the low liquid loading pipelines will cause pits or scratches on the pipe wall, and further lead to wall thinning or even leaks. Annular flow is a common flow pattern in pipeline. The particles in annular flow distribute in the liquid film and the gas core, and there are two existence forms for the solid particles in the gas core: wrapped in droplets and not be wrapped. In this paper, gas-particle slip was considered in a slip model in order to calculate the erosion of the particles wrapped in droplets in the gas core and a no-slip model was proposed to calculate the erosion of other particles in the gas core. The cushion effect of gas-liquid interface and the liquid film on the solid particles was equivalent to wall roughness. Finally, a simplified numerical simulation method considering the cushion effect and the gas-particle slip was developed to predict the erosion rate of vertical pipe bends. It is found that the predictions are in good agreement with the experimental data. The ratio of the solid particles wrapped in droplets to the total number of solid particles in the gas core is 0.626. Additionally, the relationship among liquid entrainment, erosion rate and liquid film thickness is investigated.

低载液量管道中夹带的固体颗粒会在管壁上造成凹坑或划痕，进而导致管壁变薄甚至泄漏。环形流是管道中常见的流动模式。环状流中的颗粒分布在液膜和气核中，气核中的固体颗粒有两种存在形式：包裹在液滴中和不被包裹。本文在滑移模型中考虑了气体-颗粒滑移，以计算包裹在气核中液滴的颗粒的侵蚀，并提出了一个无滑移模型来计算气核中其他颗粒的侵蚀。气液界面和液膜对固体颗粒的缓冲作用相当于壁面粗糙度。最后，开发了一种考虑缓冲效应和气体-颗粒滑移的简化数值模拟方法来预测垂直弯管的侵蚀率。发现预测与实验数据吻合良好。包裹在液滴中的固体颗粒与气核中固体颗粒总数的比值为0.626。此外，还研究了液体夹带、侵蚀速率和液膜厚度之间的关系。