Concentration Effect Of Suspended Particles In Lubricating Oil Based On Surface Acoustic Standing Wave

Lubricating oils are widely used in all kinds of machinery and equipment,which are helpful for lubrication,auxiliary cooling,rust prevention,cleaning,sealing and buffering of machinery and equipment.Micron scale solid particles in lubricating oils are the most common and one of the most hazardous pollutants.They pose a great threat to safety,service life and mechanical wear.The accumulation of suspended particulates in lubricating oil will lead to premature aging of machinery,heating and fire,which will lead to catastrophic accidents and cause great economic losses and casualties.There is an urgent need to develop the theory and technology of removing suspended particulates from lubricating oils to separate the most affected wear particles in lubricating oils.The interdigital surface acoustic wave transducer is a device for separating particles by acoustic radiation force,which can be applied to purify impurity particles in lubricating oil.In this paper,Interdigital Transducer(IDT)is used to stimulate Surface Acoustic Wave(SAW),and the acoustic radiation force is controlled by standing wave.In this paper,the optimal structural parameters of the interdigital surface acoustic wave transducer are constructed by the finite element simulation.By means of printing electrodes directly printed on the piezoelectric substrate and using laser processing or cutting machine to cut microfluidic channels,a suspension particle manipulation system platform is built.The concentration effect of suspended particles in the lubricating oil is observed by experiments,which provides a reference for further separation of particles in the two stage.The research work mainly includes the following parts:(1)According to the background and significance of this research,the research status of suspended particle separation technology at home and abroad is introduced,and the research progress of SAW transducer is analyzed.The current status of separation technology of suspended particles is summarized,and the key scientific problems of this paper are put forward.(2)The stress,strain and constitutive equation based on elastic wave theory,construct the SAW constitutive equation,analyzed the basic characteristics of the SAW and the principle of standing wave,analyzes the basic structure and working principle of IDT,according to the basic characteristics of micro scale flow,we studied the mechanism of surface acoustic wave in acoustic radiation force;(3)Aiming at the design requirements and construction principles of the micro channel separation device,the numerical model of continuous micro flow is analyzed,and theinfluence rule of interdigital electrode width,electrode gap and the thickness of the substrate caused by the size change of the model is obtained.The feasibility of particle concentration under standing wave is verified by numerical simulation.(4)The geometric parameters of SAW-IDT are optimized by simulation,and two types of IDT are developed through simulation results.The suspended particulate control system platform is constructed.The phenomenon of suspended particles concentration in the lubricating oil is observed by experiments.