Numerical Simulation of Erosion of Elbow Based on Stokes Number

Using the steady state method in DPM model and the stochastic model of computational fluid dynamics numerical simulation software Fluent, the particle trajectory was tracked. In view of the influence of discrete phase on continuous phase at a series of Stokes number (S_t), the interphase coupling method was adopted to carry out the numerical simulation of particle erosion-corrosion on the elbow wall. The results show that the erosion rate in the entrance straight section of the elbow is low and uniform and that in the later section just behind the bend of the elbow is relatively large, where the particles are collected. At the exit section of the elbow, when S_t is less than 1, the erosion gradually transits from the outside along the pipe wall to the whole wall and the maximum wall erosion rate increases slightly with the increase of S_t, whereas the increment is very small. When S_t is more than 1, particles leap between the inner and outer pipe wall and on the pipe wall discontinuous punctate erosion occurs; the maximum wall erosion rate increases slightly with the increase of S_t, and the increment is very small but significantly larger than that when S_t is less than 1.