It is of great significance for the safe operation of oil equipment to know the influence of particle size and concentration on the time-averaged velocity of oil. The oil with different particle size and concentration were tested using particle image velocimetry (PIV) measurement technology in an exceedingly square tube, the instant velocity vector information of the oil flow field was non-inheritable, and the time-averaged velocity distributions were analyzed along the flow direction and normal direction. The results showed that the flow time-flow-averaged velocity of the oil-containing particles is a quasi-parabola shape along the normal direction, and its variation amplitude increases with the decrease of the particle concentration and reaches the highest value when the particle size is 25 μm. The normal time-flow-averaged velocity has the extreme value along the normal direction when the particle concentration is low, and the variation range is large; when the normal position ranges from 0 to 0.2 and above 0.2, the unidirectional of the normal time-flow-averaged velocity of the oil is reversed. The distribution of the flow time-normal-averaged velocity along the flow direction is also a quasi-parabolic shape, and its variation amplitude is more uneven with the decrease of particle concentration. Similarly, the distribution of the normal time-normal-averaged velocity along the flow direction increases with the decrease of particle concentration, and this trend is more obvious when the particle size is 25 μm. These changes make the motion characteristics of the oil unstable, which is not conducive to the stable realization of the function of the oil equipment, so the presence of particles in the oil has an important impact on the motion characteristics of the oil and even the accurate and reliable operation of the equipment.

了解油品颗粒尺寸和浓度对时均流速的影响对于石油设备的安全运行具有重要意义。在超方管内采用粒子图像测速（PIV）测量技术对不同粒径和浓度的油进行测试，油流场的瞬时速度矢量信息不可继承，并分析了油流沿线的时均速度分布。流动方向和法线方向。结果表明，含油颗粒的流动时间-流均速度沿法线方向呈准抛物线形，其变化幅度随着颗粒浓度的减小而增大，当颗粒尺寸减小时，其变化幅度达到最大值。为25微米。当颗粒浓度较低时，法向时间流平均速度沿法线方向有极值，且变化范围较大；当正常位置范围为0～0.2且大于0.2时，油的正常时间流平均速度的单向相反。流动时间法向平均速度沿流动方向的分布也呈准抛物线形，且随着颗粒浓度的减小，其变化幅度更加不均匀。类似地，法向时间-法向平均速度沿流动方向的分布随着颗粒浓度的减小而增大，并且当颗粒尺寸为25μm时这种趋势更加明显。这些变化使油的运动特性不稳定，