Study On Microfludic Inertia Separation Characteristics Of Abrasive Grain In The Engine Oil

Oil plays the role of "blood" in power machinery equipment,and plays an important role in lubrication,rust prevention,equipment cooling and shock absorption.Whether mechanical equipment can maintain normal operation is closely related to the cleanliness of oil.Studies shows that the abrasive particles produced by mechanical wear in the engine oil are the main causes of equipment operation failure.The oil contamination grade standard is based on the size and number of particles per milliliter of oil.Current methods for detecting abrasive particles in motor oils are applicable to most mechanical equipment,but are relatively accurate for highprecision mechanical equipment.And the targeted wear particle detection can ensure the stable operation of the equipment and prolong the service life of the equipment.Microfluidic chips have developed rapidly in particle manipulation in recent years.For the detection of particles and cells,microfluidic chips have the advantages of high sensitivity,portability,and ease of on-site detection.Microfluidic chip manipulation of particles is mainly divided into active and passive,active need to add an external force field,the device is complex and the processing sample flow is low,for passive particle manipulation,inertial effects of particles in the flow field with the flow rate of the fluid increases Gradually increase,particles can be manipulated at high flux.This article combines the oil detection technology and the inertial microfluidic particle manipulation method to sort abrasive particles with different particle sizes in the microfluidic chip,and increase the detection accuracy by counting separately.Starting from the sorting of low-viscosity spherical particles,the migration theory was explored and applied to the separation of high-viscosity irregular particles.Therefore,starting from the sorting of polystyrene beads with diameters of 5 μm and15 μm in aqueous solution,the numerical simulation and experimental investigation of the motion of the particles in the helium channel were carried out,and the results were 5 μm and 15 μm.The optimal separation conditions for polystyrene beads in water were optimized,and the microchannel structure was optimized.The effect of microchannel inlet flow rate on the separation results was analyzed by numerical simulation.Based on the sorting study of the aqueous solution of polystyrene beads,a movement model of the abrasive particles along the flow field was established to simulate the movement of the abrasive particles in the oil channel in the channel.In the numerical simulation,the shape of the abrasive particles was corrected,and theoptimum separation conditions for 5 μm and 15 μm iron powder particles in a specific viscosity oil were obtained through numerical simulation and experimental studies.The effects of microchannel inlet flow rate,channel size and oil viscosity on the separation of iron powder particles were analyzed.In this paper,the microfluidic inertial sorting of oil abrasive particles can be used to further improve the accuracy of abrasive particle detection and expand the application of inertial migration of complex shape particles in high viscosity fluids.