供水管道中球体运动受力特性分析

Mechanical Behavior of a Moving Sphere in Water Supply Pipelines

球形检测器在管道内部运行时会受到管内流体状态的影响,可能会使球体在管道内发生不稳定滚动,严重影响球形检测器检测效果.针对球体在供水管道中的动力学特性进行了理论分析,研究了球体运动状态与管内流体状态各参数因素之间的关系,给出了球体稳定运行条件,建立了供水管道中球体运动的受力模型;然后对受力数值模型进行仿真分析,得到球体周围的流体流速与压力分布规律,流体和球体相对速度与球体阻力系数、升力系数、力矩系数之间的关系,拟合了流体和球体相对速度与球体滚动角速度之间的函数关系;最后实验验证了理论分析和数值仿真的合理性,并由流体入口速度、球质心运动速度、球滚动角速度、球滑动速度和流体与球质心相对速度之间的关系,求出了球的滚动和滑动速度,为球形检测器结构质密参数管内流体状态参数之间的匹配优化设计提供理论指导,从而使其具有较好的管径适应性和管道通过性.

A spherical detector running inside the pipe will be affected by the fluid state inside the pipe,causing the detector to roll unstably in the pipe,and seriously affecting its detection effect.Based on the theoretical analysis of the dynamic characteristics of the detector in the water supply pipeline,the relationship between its motion state and the parameters of the fluid state in the pipeline is studied,its stable operation condition is given,and its force model in the water supply pipeline is established.Then,the numerical model of the force is simulated and analyzed to obtain the flow velocity and pressure distribution law around the detector,the relationship between the relative velocity of the fluid and the detector and the drag coefficient,its lift coefficient and torque coefficient,and the functional relationship between the relative velocity of the fluid and the detector and its rolling angular velocity is fitted.Finally,the experiment verified the rationality of the theoretical analysis and numerical simulation,and the rolling and sliding velocity of the detector were calculated from the relationship between the inlet velocity of the fluid,the motion velocity of the center of mass of the detector,the angular velocity of its rolling,its sliding velocity and the relative velocity of the fluid and the center of its mass.It provides the theoretical guidance for the matching optimization design of the fluid state parameters in the pipe of the structure of the detector,so that it has better pipe diameter adaptability and pipeline passing ability.