基于斯托克斯数的弯管冲蚀数值模拟

摘要

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 (St),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 St 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 St,whereas the increment is very small.When St 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 St,and the increment is very small but significantly larger than that when St is less than 1.%利用计算流体力学数值模拟软件Fluent,采用DPM模型中的稳态方法和随机轨道模型,进行颗粒的运动轨迹追踪.考虑到离散相对连续相的影响,采用相间耦合方法,基于斯托克斯数(St)进行了一系列颗粒对弯管管壁的冲蚀数值模拟.结果表明:弯管入口直管段,冲蚀速率很小且均匀;在随后的弯管段,颗粒聚集较多,该处冲蚀速率较大;出口直管段,当St＜1时,冲蚀情况由弯管外侧沿着管壁逐渐均匀过渡到整个管壁四周,管壁最大冲蚀速率随St的增大而略有增大,但增幅很小.当St＞1时,颗粒在内外管壁之间变性跃移,管壁冲蚀呈现不连续的点状冲蚀,管壁最大冲蚀速率随St的增大而略有增大,增幅很小,但明显大于St＜1时的最大冲蚀速率.