Numerical Study Of Indoor Particle Motion Based On LBM Method

With the emphasis on health,people pay more and more attention to indoor air quality.Particulate matter is the main pollutant in the room.Studying the rule of indoor particle movement and deposition is of great significance for improving air quality.In this paper,the particle motion in the laminar channel and the movement and deposition of particles in the indoor turbulent environment are studied.The specific contents are as follows:First of all,the movement and deposition of particles by different forces in 2D and 3D within the channel are studied,the influence of drag force,gravity force,Brown force,the saffman lift force on the particle movement are analyzed.The results show that in two-dimensional and three-dimensional laminar flow in the channel,the drag force is the main force of particle movement for different diameter and density.Gravity has effect on particles of different diameters,when the particle diameter is small,it has less effect on the particle motion,the variation of particle density has almost no effect on the particle movement,when the particle diameter is larger,gravity has great influence on the movement of the particles.Only when the diameter of the particle is very small,the force of the Brown force is obvious.The effect of the saffman lift on the particles of different diameter can be ignored.Secondly,the motion of particles in two-dimensional space is numerically simulated,and particle diameter,particle density and wall temperature are analyzed.The results show that the number of deposition particles on the top wall decreases with the increase of particle diameter,and the number of particles on the lower side increases with the increase of particle diameter.The number of particles deposited on the left and right walls is almost unaffected by the change of diameter.When the particle diameter is larger,the change of particle density has a great influence on the movement of particles.When the diameter of the particles is small,the change of particle density has little effect on the movement of particles.When the left wall is at low temperature,there are more particles coming out of the room,and fewer particles are deposited on the upper and lower walls.When the left wall is at high temperature,there are fewer particles coming out of the room,and more particles are deposited on the upper and lower walls.Finally,the particle motion in the three-dimensional chamber is numerically calculated,and the influence of particle diameter,particle density and wall temperature is analyzed.The results show that the number of particles deposited on the upper wall decreases with the increase of particle diameter in the three dimensional room,and the number of particles on the lower side increases with the increase of particle diameter,and the number of particles deposited on the left and right walls is almost unchanged.For larger diameter particles,the change of density has great influence on the motion of particles.When particle diameter is small,the change of particle density almost has no effect on the movement of particles.The change of the left wall temperature has little influence on the movement and deposition of the particles.