Study On Bubble Impact Kinetics And Processing Effect In Gas-Liquid-Solid Three-Phase Abrasive Flow

The gas-liquid-solid three-phase particle flow is widely found in various engineering fields,and the bubble burst process is a complex gas-liquid three-phase coupling problem.At present,the effect of particle velocity disturbance and wall contact effect caused by bubble burst is not clear.In view of the above problems,the dynamic characteristics of gas-liquid three-phase abrasive grain flow and its experimental research are discussed.The main contents are as follows.(1)Using the multiphase fluid volume(VOF)model and the k-? turbulence model to establish the gas-liquid-solid three-phase particle flow bubble crack dynamics model;combined with the pressure implicit operator segmentation method to solve the unsteady Navier-Stokes(NS)equation,the dynamic characteristics of the collapse process of the single and multiple bubbles near the wall and the wall are obtained,and the effect of the velocity on the velocity of the particles and the impact of the flow wall is revealed.The results show that in the high-speed turbulent environment,the bubble burst is easy to occur from the tail of the bubble due to the large difference in pressure inside and outside the bubble tail.The smaller is the distance between the bubble center and the wall,the greater the force of the micro jet on the wall.The greater the speed,the less time required for the complete rupture of the bubble,but the time required for the complete rupture of the bubble increases as the flow rate increases to 60 m / s.The double bubble rupture-polymerization process prolongs the time of the bubble burst,The acceleration of movement.(2)Based on the three-phase coupling calculation method of bubble particles,the bubble particle dynamic model was established.Based on the above model,the controllability of the surrounding particles in the near-wall micro-nano bubble burst.The results show that the motion and rupture of a single bubble in the flow field will disturb the motion of the surrounding particles,but the influence of the instantaneous velocity on the surrounding particles is two orders of magnitude less than that in the case of failure.In the case of rupture during bubble movement,the smaller the initial diameter of the bubble or the smaller the distance between the bubbles and the particles,the greater the effect of the local jet generated by the bubble burst on the surrounding particles.(3)Based on the particle image velocity measurement(PIV)technology,to build gas-liquid-solid three-phase bubble movement process observation experimental platform.According to the relevant conclusions obtained from the theoretical research,the corresponding observation experiments are carried out to verify the correctness of the model and the method.At the same time,the gas-liquid-solid three-phase abrasive grain polishing experiment was carried out to further verify the conclusion of numerical simulation.The results can provide a reference for the study of the coupling mechanism of the three-phase flow and the cavitation erosion mechanism.It can also provide technical support for the gas-liquid-solid three-phase flow regulation in the fields of mechanical,chemical and metallurgy.