Numerical Simulation Of Acoustic Wake Effect Of Particle Base On Two-dimensional Lattice Boltzmann Method

Acoustic agglomeration technology is a dust collector pretreatment technology with great economic potential.Acoustic wave wake effect is considered as one of the main mechanisms of particle acoustic agglomeration.At present,the research on acoustic wake effect mainly focuses on experimental research and theoretical analysis.Lattice boltzamnn method(LBM),as a new Computational Fluid Dynamics(CFD)method,has advantages over conventional CFD method in dealing with micro-flow and particle-laden flow.In this paper,the LBM program is edited by MATLA B to simulate the acoustic wake effect of two-dimensional circular particles.The single relaxation collision equation in LBM and D2Q9 velocity model are used to simulate the flow of weakly compressible fluid.Momentum exchange method(ME)and YMS format in moving boundary method are used to realize fluid-solid two-way coupling.Firstly,the motion of a single circular particle in a plane sinusoidal sound field is studied by theoretical analysis.The effects of sound pressure level,frequency and particle size on particle vibration are investigated.Then,the vibrations in the acoustic field has been simulated by LBM,and has been compared with theoretical results.It is found that the simulation curve is close to the theoretical curve,which proves the feasibility of applying LBM simulation to the study of particle motion in the acoustic field.Finally,LBM was used to simulate the agglomeration and repulsion of two particles in the sound field caused by wake effect.It is found that the intensity of attraction(or repulsion)between particles varies with the angle between the particle line and the sound field.Sound pressure level,sound frequency and particle spacing will affect the intensity of attraction(or repulsion)and the angle range of attraction(or repulsion)between particles.In the simulation process,sound waves propagate along the x-direction,and the direct attraction and repulsion of particles are decomposed into x and Y directions.(1)Sound pressure level has no effect on the angular distribution of the attraction and repulsion of particles in the X and Y directions.However,the sound pressure level has an effect on the agglomeration and repulsion strength.The greater the sound pressure level,the stronger the attraction or repulsion between particles.(2)The larger the frequency of sound wave,the smaller the attraction intensity in the X direction,the smaller the angle range of the attraction area,the greater the intensity of the repulsion and the larger the angle range of the repulsion area.(3)The smaller the particle spacing is,the larger the angle range of particle attraction in the X direction is,the larger the angle range of attraction is,the stronger the attraction is,and the weaker the repulsion is.