湍流作用下颗粒旋转对海水管道的冲蚀磨损过程分析

Erosion Process Analysis of Particle Rotation on Seawater Pipe under Turbulence

为准确预测海水管道携沙受到的冲蚀磨损,对湍流作用下颗粒旋转对海水管道的冲蚀磨损过程进行分析。基于计算流体力学和冲蚀磨损理论,建立颗粒旋转的数学模型。验证双向耦合对流场的影响,计算不同冲蚀磨损模型在颗粒旋转条件下的磨损率,讨论斯托克斯数(St)对磨损位置的影响,分析颗粒旋转条件下不同流速对应的冲蚀磨损过程。结果表明:在颗粒旋转条件下,颗粒在弯头处的运动轨迹发生明显改变,一部分颗粒在惯性力的驱动下直接冲击弯头,另一部分颗粒与弯头碰撞之后在旋转升力的作用下环绕管壁运动,使得颗粒与壁面的碰撞次数增多,颗粒获得充分发展,管道最大磨损率上升。

In order to predict the erosion of sand carrying sea water pipe accurately, the erosion process caused by the rotation of particles in turbulent flow are analyzed. Based on computational fluid dynamics and erosion theory, a mathematical model of particle rotation is established. The influence of two-way coupling on the flow field is verified, the wear rates of different erosion models under particle rotation conditions are calculated, the influence of Stokes number on the wear position is discussed, and the erosion processes corresponding to different flow rates under particle rotation conditions are analyzed. The results show that the trajectory of the particles at the elbow changes significantly under particle rotation conditions. Some of the particles directly impact the elbow under the driving of inertia force. The others collide with the elbow and then moves around the pipe wall under the driving of rotating lift force. The number of collisions between the particles and the pipe wall is thus increased, the particles flow sufficiently, and the maximum erosion rate of pipes is increased.