Numerical study on the particle erosion of elbows mounted in series in the gas-solid flow

Solid particles in the fluid cause great damages to elbows. In particular, the erosion behavior of elbows mounted in series is more complicated than a single elbow. In the present study, the Eulerian-Lagrangian approach is applied to solve the gas-solid flow in the pipeline with four elbows mounted in series. Three erosion models are used for prediction and Zhang et al. model is finally selected for the development of the numerical model after comparison with the experimental data. Based on the numerical model, the effect of particle diameter, connection length between elbows, and curvature radius on the erosion behavior of four elbows are investigated through the particle trajectory analysis and particle impact characteristic at the elbows. Obtained results show that the erosion behavior of downstream elbows of the connecting pipe is considerably affected by the connection length. The sensitivity of four elbows to particle size is significantly different. Compared with small size particles, large size particles cause greater damage at the first elbow and less erosion at downstream elbows. Additionally, due to the secondary collision of particles, V-shaped erosion morphology appears at elbows and gradually evolves into the closed ring under a larger curvature radius.