一种减轻固粒对壁面冲蚀磨损的新方法

A New Way to Reduce Wall Erosion Caused by Solid Particles

针对带固粒的近壁流场,提出了在壁面上开凿纵向浅沟槽以减轻固粒对壁面冲蚀磨损的方法.采用改进的k-ε湍流模式和气-固两相双向耦合模型,计算了流场中颗粒的速度、轨迹以及固粒对壁面的冲蚀磨损,并进行了相应的试验对比.结果表明:在壁面上开凿纵向沟槽能减轻固粒对壁面的磨损;在一定的沟槽高度下,当沟槽宽度同沟槽间距离相等时,减轻磨损的效果最明显;在一定颗粒尺寸范围内,大颗粒导致磨损质量损失增大,当颗粒尺寸超过某一临界值后,颗粒尺寸对磨损的影响较小.进口处颗粒运动方向对壁面磨损具有直接影响.

It was suggested to reduce the wall erosion caused by particles in a particulate flow by digging slot on the wall. Thus the improved kε turbulence model and twoway coupling method were used to calculate the particle velocities and trajectories, and the wall erosion rate caused by particle impact. The calculated results were verified by comparison with the corresponding experimental ones. As the results, the calculated results agreed well with the experimental ones. The wall erosion attributed to the particle impact was significantly decreased by digging streamwise slot on the wall. At a fixed slot height, the reduction of the erosion rate was significant when the slot width was almost identical to the gap between two slots. Within a certain region of the particulate size, larger particles led to higher erosion rate of the wall, while at a particle size exceeding a critical value, the erosion rate of the wall had little dependence on the particle size. Moreover, the erosion rate of the wall was closely related to the initial inlet angle of the particles.