Contrastive Simulation Research on PM₁ Particles Deposition in Two Narrow Rectangular Channels

This paper intends to make numerical simulation to study the regularity of the deposition of PM1 particles under the turbulent condition at different temperatures in two narrow vertical rectangular channels.The channel 1 length is 1000mm,and the sectional dimension is 20 mm×20mm.Channel 2 sectional dimension is 10 mm×30 mm,and channel 2 length is as long as channel 1.The gas phase uses the standard k– model and the PM1 particles use DPM（Discrete Phase Model）.The study found that,the turbulent diffusion,the thermophoresis and the secondary flow together make the PM1 particles gather in the channel near-wall regions,the turbulent diffusion make PM1 particles concentrate in the channel near-wall regions,and the important reason of PM1 particles concentration is the secondary flow in the corner.In the temperature field in near-wall regions,it can be found that the thermophoretic force is the most important factor for the PM1to deposit on the cold wall.With the rise of the main flow temperature,the random motion and diffusion of the PM1 particles tend to be intensified due to the significant intensification of the PM1 particles Brownian motion,which is not conducive to form the stable gathering areas of PM1 particles in the near-wall regions,and it tends to weaken the deposition of PM1particles on the cold wall.