In the process of hydraulic fracturing,the ground high-pressure manifold is affected by the complex flow of liquid-particle two-phase fracturing fluid in the pipe,which makes it suffer severe erosion damage for a long time.Among all kinds of high-pressure manifold components,the erosion damage of elbow is the most serious.In order to improve the erosive wear of fractured double-bends,DPM model and RNG k-ε turbulence model were used to comprehensively analyze the influence of Stokes numbers (St),gravity directions,particle sizes and flow velocities on the erosive wear of series double-bends.The results show that the erosion zone is mainly determined by St and gravity direction.When St is less than 1,the maximum erosion rate increases linearly with the increase of particle size.When St is more than 1,the maximum erosion rate increases exponentially.The effect of velocity on erosion rate is much larger than that of particle size when St is the same.In the gravity direction of downflow,the critical particle size of the damage region completely transferred to the second elbow with the increase of St is significantly smaller than that of the upflow.Although the gravity direction has an enhancing effect on the erosion damage of co-directional impact particles,its effect on erosive wear is far less than that of particle size.