Numerical study of elbow erosion due to sand particles under annular flow considering liquid entrainment

Sand particle erosion is always a challenge in natural gas production.In particular,the erosion in gas-liquid-solid annular flow is more complicated.In this study,a three-phase flow numerical model that couples the volume of fluid multiphase flow model and the discrete phase model was developed for prediction of erosion in annular flow.The ability of the numerical model to simulate the gas-liquid annular flow is validated through comparison with the experimental data.On the basis of the above numerical model,the phase distribution in the pipe was analyzed.The liquid entrainment behavior was reasonably simulated through the numerical model,which guaranteed the accuracy of predicting the particle erosion.Additionally,four erosion prediction models were used for the erosion calculation,among them,the Zhang et al.erosion model predicted the realistic results.Through the analysis of the particle trajectory and the particle impact behavior on the elbow,the cushion effect of the liquid film on the particles and the erosion morphology generation at the elbow were revealed.