Effect of Particle Concentration and Size on the Time-Averaged Velocity of Oil

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.